<DOCUMENT>
 <TYPE>EX-10.14
 <SEQUENCE>4
 <FILENAME>dex1014.txt
 <DESCRIPTION>CAJARO CONTRACT
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                                                                                1
                                                                    EXHIBIT 10.14
 EMPRESA COLOMBIANA
 DE PETROLEOS
 ECOPETROL                                          "CAJARO" ASSOCIATION CONTRACT
                               ASSOCIATION CONTRACT
 ASSOCIATE      :   HARKEN DE COLOMBIA LIMITED
 SECTOR         :   CAJARO
 EFFECTIVE DATE :   February 18, 2002
                    -----------------
 The contracting parties, as such: on one Part, the Empresa Colombiana de
 Petroleos hereinafter referred to as ECOPETROL, an industrial and commercial
 State-owned enterprise authorized by law 165 of 1948, actually ruled by its
 by-laws, reformed by Decrees 1209 of June 15, 1994 and 2933 of December 10,
 1997, with head office in Bogota, D.C., represented by ALBERTO CALDERON ZULETA,
 of legal age, bearer of citizenship card No. 19'248.238 issued in Bogota, based
 in Bogota, D.C., who states: 1. That in his capacity as President of ECOPETROL,
 acts in representation of this Company, and 2. That for the execution of this
 contract he has been authorized by the Board of Directors of ECOPETROL, as
 witnessed in Minutes No. 2264 of December 14, 2001, and on the other hand HARKEN
 DE COLOMBIA LIMITED, company organized pursuant to the laws of the Caiman
 Islands, with a branch established in Colombia and with head offices in Bogota,
 D.C., pursuant to Public Deed No. 406 of February 19, 1993, executed in Notary
 Eleven (11) of Bogota, represented by GABRIEL GUSTAVO CANO VELASQUEZ, of legal
 age, Colombian citizen, bearer of citizenship card number 8'265.559, who
 declares: 1. That in his capacity as the Main Legal Representative he acts as
 the representative HARKEN DE COLOMBIA LIMITED, 2. That to execute this contract
 he is fully authorized as per the Certificate of Incorporation and Legal
 Representation issued by the Chamber of commerce of Bogota, D.C., and 3. That
 THE ASSOCIATE assures to have the financial capacity, technical competence and
 the professional abilities necessary to execute the activities to which this
 contract refers to.
 Under the above conditions, ECOPETROL and THE ASSOCIATE declare that they have
 entered into the contract contained in the following Clauses:
                          CHAPTER I - GENERAL PROVISIONS
 CLAUSE 1 - OBJECT OF THIS CONTRACT
 1.1       The object of this contract is the exploration of the Contract Area
           and the exploitation of such nationally owned hydrocarbons that may be
           found therein, described in Annex A that is part of this contract.
 1.2       Pursuant to Article 1o. of Decree 2310 of 1974, the exploration and
           exploitation of nationally owned hydrocarbons are entrusted to
           ECOPETROL, company that may, directly or under contracts with Private
           Parties, carry out such activities. Based on such provision mentioned,
           ECOPETROL has agreed with THE ASSOCIATE to explore the Contract Area
           and to exploit such Hydrocarbons as may be found therein, under the
           terms and conditions set
 <PAGE>
                                                                                2
           forth in herein, in Annex "A", Annex "B" (Operating Agreement) and
           Annex "C" (Lineaments for the Preparation of the Development Plan)
           that make part of this contract.
 1.3       Without prejudice of the provisions hereunder, it is understood that
           THE ASSOCIATE shall have the same rights and obligations in respect to
           the Hydrocarbons produced in the contract area and to its share of the
           same as are assigned under the Colombian Laws to anyone exploiting
           nationally owned Hydrocarbons in this country.
 1.4       ECOPETROL and THE ASSOCIATE agree to carry out the exploration and
           exploitation operations within the terms of this contract in the
           Contract Area, that they shall share between themselves the costs and
           risks thereof in the proportion and under the terms set forth in this
           contract and that the Hydrocarbons produced shall belong to each Party
           pursuant to the proportions set forth in this contract.
 CLAUSE 2 - APPLICATION OF THE CONTRACT
 This contract applies to the Contract Area, identified, and the boundaries of
 which are described in Clause 3 and Annex A of this contract, or to such portion
 thereof, when areas have been restituted pursuant to this contract.
 CLAUSE 3 -CONTRACT AREA
 The area Contract comprises thirty four thousand one hundred and ninety five
 (34.195) hectares with seven thousand fifty eight (7.058) square meters and is
 located within the municipal jurisdiction of Mani in the department of Casanare.
 The cartographic information was taken from the Political Map of Colombia,
 digital file of the I.G.A.C., on scale 1:1'500.000.
 This area is described on Annex "A" that is part of this contract.
 Paragraph 1. - Whenever a person files a claim pretending to be the owner of the
 property of the subsurface Hydrocarbons in the Contract Area, ECOPETROL shall
 handle the case and assume the obligations required.
 Paragraph 2.- In the case in which part of the Contract Area extends over the
 areas that are or that have been reserved and declared to be within a system of
 National Parks, THE ASSOCIATE is obliged to obey the conditions ruled by the
 corresponding authorities, without it being considered that this contract has
 been modified and without there being a right to make any claim against
 ECOPETROL, pursuant to that agreed on in Clause 30 (numeral 30.2) of this
 contract.
 CLAUSE 4 - DEFINITIONS
 For the purpose of this contract, the terms mentioned hereinafter, shall have
 the following meaning:
 4.1       Contract Area: Is the land described in Clause 3 hereinabove, and
           described in Annex "A" of this contract.
 <PAGE>
                                                                                3
 4.2       Field: Such portion of the Contract Area in which there are one or
           more structures and/or stratigraphic traps totally or partially
           overlaid, with one or more productive Reservoirs or that the capacity
           to produce Hydrocarbons in commercial amounts has been verified. Such
           reservoirs may be found vertically and/or laterally separated by
           geological barriers or impervious stratums, or both.
 4.3       Commercial Field: Is the field accepted by ECOPETROL able to produce
           Hydrocarbons in economically exploitable quantity and quality, in one
           or more of the Production Objectives defined by ECOPETROL at the time
           of acceptance of the commerciality, without prejudice that during the
           exploitation phase other Production Objectives may be found.
 4.4       Gas Field : Is such that based on the information supplied by THE
           ASSOCIATE, is classified by ECOPETROL as a Non Associated Natural Gas
           Producer (or free natural gas) in the definition of its commerciality
           .
 4.5       Executive Committee: Is the body established within thirty (30) days
           following the acceptance of the first Commercial Field, to supervise,
           control and approve all the operations and actions that are carried
           out during the term of the contract.
 4.6       Direct Exploration Costs: Are the monetary expenses reasonably
           incurred in by THE ASSOCIATE through the acquisition of seismic and
           the drilling of Exploratory Wells, as well as for the locations,
           termination, equipment and testing of such wells. The Direct
           Exploration Costs do not include administrative or technical support
           from the head office or central offices of the Company.
 4.7       Joint Account: Are the records to be kept by means of books of
           accounts pursuant to the Colombian laws, for crediting or debiting the
           Parties for their share in the Joint Account of each Commercial Field.
 4.8       Budget Execution: Are the resources actually committed and/or spent in
           each of the programs and projects approved for a given calendar year.
 4.9       Structure: It is the geometrical form with geological closing
           (anticlinal, synclinal, etc.) that present the formations in which
           fluid accumulations are found.
 4.10      Effective Date: It is the day in which the sixty (60) calendar day
           period expires, as from the date of this contract is signed, as of
           which all the terms agreed upon therein shall be counted,
           independently from the date of approval of the contract by the
           Ministry of Mines and Energy.
 4.11      Cash Flow: It is constituted by the movement of monies (income and
           disbursements) to be made by the Joint Account in order to meet the
           different obligations Contracted by the Operator for the normal
           progress of the operations.
 4.12      Associate Natural Gas: Mixture of light Hydrocarbons in a gaseous
           state or in solution in the Reservoir and that is produced jointly
           with liquid hydrocarbons.
 4.13      Non Associated Natural Gas (Production of): Are those Hydrocarbons
           produced in a gaseous state on surface and reported to standard
           conditions, with average values
 <PAGE>
                                                                                4
           (pondered by production), of initial relation Gas/Oil greater than
           15.000 standard cubic feet of gas per barrel of liquid Hydrocarbon and
           one molar composition of heptane plus (C7 +) less than 4.0%.
 4.14      Direct Expenses: Are all expenditures payable by the Joint Account for
           payments of personnel directly engaged in the Company, purchase of
           materials and supplies, contracting of services with third parties and
           other general expenses required by the Joint Operation in the normal
           performance of its activities.
 4.15      Indirect Expenses: Are those expenditures payable by the Joint Account
           for technical and/or administrative support, which the operator with
           his own organization, gives to the joint operation.
 4.16      Commercial Interest Rate: When referring to pesos, it shall be the
           current interest rate at the time of the delay; in dealing with
           dollars of the United States of America, it shall be the prime rate
           fixed by the LIBOR (London Interbank Borrowing Offered Rate), three
           (3) months for dollar deposits, increased by four percentage points
           (LIBOR +4%).
 4.17      Interest in the Operation: Is the share in the obligations and rights
           acquired by each party in the exploration and exploitation of the
           Contract Area.
 4.18      Development Investment: The sums of money invested in goods and
           equipment capitalized assets for the joint operations in a Commercial
           Field upon acceptance of the existence by the parties.
 4.19      Hydrocarbons: All organic compounds constituted mainly by the natural
           mixture of carbon and hydrogen as well those substances that accompany
           them or that are derived from them with the exception of helium and
           strange gases.
 4.20      Gaseous Hydrocarbons: All Hydrocarbons produced in a gaseous state in
           surface and reported to standard conditions (1. absolute pressure
           atmosphere and a temperature of 60(0)F.)
 4.21      Liquid Hydrocarbons: Crude and condensed oil and those produced in
           such state as a result of the gas treatment when required, reported to
           standard conditions.
 4.22      Production Objectives: Are the reservoirs located in the commercial
           field discovered and tested as commercial producers.
 4.23      Joint Operation: The activities and work performed or in the process
           of being performed, on behalf of the parties and on their own account.
 4.24      Operator: The person designated by the parties to directly carry out,
           on their behalf, and without representing them, the operations
           necessary to explore and exploit the Hydrocarbons found in the
           Contract Area.
 4.25      Parties: On the Effective Date, ECOPETROL and THE ASSOCIATE.
           Subsequently and at any time, ECOPETROL on the one hand, and THE
           ASSOCIATE and/or its assignees on the other.
 <PAGE>
                                                                                5
 4.26      Exploration Period: The time available to THE ASSOCIATE for complying
           with the obligations set forth in Clause 5 of this contract, which
           shall not exceed six (6) years as from the Effective Date, except in
           the cases contemplated in Clauses 5 (numeral 5.4), 9 (numeral 9.3) and
           34.
 4.27      Exploitation Period: The time elapsing from the end of the exploration
           period, or that of retention when necessary, to the end of this
           contract.
 4.28      Retention Period: The time required by THE ASSOCIATE and granted by
           ECOPETROL to being the exploitation period of each gas field
           discovered in the Contract Area, that due to its particular conditions
           is not able to be developed in a short term, requiring an additional
           term for the execution of feasibility studies, of construction of
           infrastructure and/or marketing development.
 4.29      Development Plan: Is the guide document to perform technical,
           efficient and economical exploitation operations of each field and
           shall contain, among other aspects, the development strategy, the
           environmental considerations, the activities to be developed, the
           Production forecasts for short and medium term, an estimate of the
           investment and expenses for the following five years and specifically,
           a description of the projects, the operations program and the Budget
           for the remaining of the present year or of the following year, as is
           the case. The lineaments for this development plan are described in
           Annex "C" that is part of this contract.
 4.30      Exploration Well: Any well designated as such by THE ASSOCIATE to be
           drilled or deepened on its behalf, in the Contract Area in search of
           new reservoirs or to verify the extension of a reservoir or to
           determine the stratigraphy of an area. For the fulfillment of the
           obligations contemplated in Clause 5 of this contract, the
           corresponding drilling well shall be previously classified between
           ECOPETROL and THE ASSOCIATE.
 4.31      Discovery Well: Is that exploration well in which the existence of one
           or more reservoirs is discovered or confirmed and that may require
           subsequent evaluation to determine whether such reservoir or
           reservoirs may be commercially exploited.
 4.32      Exploitation Well (or of Development): Any well previously scheduled
           as such by the Executive Committee for the production of Hydrocarbons
           discovered in the objectives of production in the area of each
           commercial field.
 4.33      Budget: The basic planning instrument whereby the resources are
           allocated for specific projects to be applied within a calendar year
           or part of a year, in order to achieve the goals and objectives
           proposed by THE ASSOCIATE or by the Operator.
 4.34      Extensive Production Tests: The operations performed in one or more
           producing Exploration Wells, to evaluate the production and behavior
           conditions of the reservoir with temporary production installations.
 4.35      Reimbursement: Is the payment of fifty percent (50%) of the Direct
           Exploration Costs incurred in by THE ASSOCIATE.
 <PAGE>
                                                                                6
 4.36      Exploration Operations. The operations performed by THE ASSOCIATE as
           related to the search and discovery of Hydrocarbons within the
           Contract Area.
 4.37      Reservoir: All rocks under the surface where Hydrocarbons in their
           porous space are accumulated, under production or that has the
           capacity to produce Hydrocarbons and that behaves as an independent
           unit as far as its petrophysical and fluid properties and that has a
           common pressure system throughout its entire extension.
                             CHAPTER II - EXPLORATION
 CLAUSE 5 - TERMS AND CONDITIONS
 5.1       THE ASSOCIATE is committed to carry out the exploration operations
           pursuant to the regulations and modern practices commonly accepted and
           in use by the international oil industry and to fulfill the legal and
           regulatory provisions in force. The exploration period shall be
           divided in three (3) phases, the first with a duration of twelve (12)
           months, the second phase with a duration of twelve (12) months and the
           third phase with a duration of twelve (12) months. The first phase
           begins on the Effective Date and the following on the calendar day
           immediately following the conclusion of the previous phase.
           During the exploration period, THE ASSOCIATE is obliged to carry out,
           as a minimum, the following exploration operations: during the first
           phase, THE ASSOCIATE must carry out the drilling of one (1)
           Exploration Well until reaching the formations that can produce
           Hydrocarbons in the Contract Area. With this well, the exploratory
           obligation corresponding to the fifth year of the exploration period
           of the Bocachico Association Contract is fulfilled.
           At the end of the first phase, THE ASSOCIATE shall have the option to
           resign from the Association Contract, provided having previously
           complied with the exploratory commitments agreed on for the present
           phase.
           During the second phase, THE ASSOCIATE must carry out the drilling of
           one (1) exploration well until reaching the formations that may
           produce Hydrocarbons in the Contract Area.
           At the end of the second phase, THE ASSOCIATE shall have the option to
           resign from the Association Contract provided having previously
           fulfilled the exploratory commitments agreed on for the present phase.
           During the third phase, THE ASSOCIATE shall drill one (1) Exploratory
           Well to depth so as to reach the formations capable of producing
           Hydrocarbons in the Contract Area.
           At the expiration of the exploration period, the contract shall end if
           the extension thereof has not been requested and authorized pursuant
           to Numeral 5.2 of this Clause, or if a field has not been discovered.
 <PAGE>
                                                                                7
 5.2       If THE ASSOCIATE has satisfactorily complied with the obligations
           stipulated in Clause 5.1, ECOPETROL, at the request of THE ASSOCIATE,
           shall annually extend the exploration period, up to three (3)
           additional years, for such purpose, THE ASSOCIATE must inform its
           intention to continue with the exploration in the Contract block with
           an anticipation not lower than ninety (90) days of the date of
           termination of the Exploration Period, accompanying such request with
           the proposal of the Exploration Operations Program to be performed
           during each extension period. Within ninety (90) days following the
           date of receipt of the request of THE ASSOCIATE in ECOPETROL, the
           PARTIES shall be able to agree on the Exploration Operations Programs
           to be performed during such extensions. If no agreement is reached,
           THE ASSOCIATE is obliged to carry out as a minimum, Exploration
           Operations in the Contract Area, consisting in the drilling of one (1)
           Exploration Well per year. At the end of each of the extensions, which
           duration is one year, THE ASSOCIATE, shall have the option to resign
           from the Association Contract having previously fulfilled the
           exploratory commitment agreed on for each of them.
 5.3       At its judgment, and at its own cost and risk, THE ASSOCIATE may
           perform additional Exploration Operations to those agreed on for the
           Phase or Stage of the Exploration Period under development. However,
           if THE ASSOCIATE wishes to have such additional Exploration Work
           accredited to the fulfillment of the exploratory commitments of the
           following phase or stage of the Exploration Period, it must request
           ECOPETROL to issue the corresponding approval. If the request is
           accepted by ECOPETROL, it shall determine the form and amount in which
           the transfer of the mentioned commitments is to be made.
 5.4       If at the end of the six (6) year Exploration Period, THE ASSOCIATE
           has drilled one or several Discovery Wells that show the possible
           existence of a Commercial Field, previous written request by THE
           ASSOCIATE, ECOPETROL may authorize the extension of the Exploration
           Period for the time necessary, that shall not exceed two (2) years, so
           that THE ASSOCIATE may have the opportunity to prove the existence of
           such Commercial Field. To bring into effect that herein set forth,
           before finishing the Exploration Period and simultaneously with the
           request, THE ASSOCIATE must provide ECOPETROL with the maps and other
           descriptions of the area considered as capable of producing
           Hydrocarbons, the Exploration Operations program and other operations
           that THE ASSOCIATE plans to carry out and the budget to carry out such
           work at its own cost and risk, to determine the extension of the
           Reservoir or Reservoirs discovered and to show the existence of a
           Commercial Field, without prejudice of that established in Clause 8.
           To give application to the partial restituted of the areas during this
           extension of the Exploration Period, THE ASSOCIATE shall retain the
           area that is the largest between fifty percent (50%) of the Contract
           Area and the area it considers capable of producing Hydrocarbons plus
           its zone of reserve of two and a half (2.5) kilometers wide around the
           previous one, within the limits of the Contract Area. If the
           operations program proposed adjusts to the international standards and
           has the object to show the commerciality of the discovered Reservoirs
           within the term established, ECOPETROL shall issue its authorization
           for the execution of this program.
 5.5       During the life of this contract and observing that established in
           Clause 7 of the same, THE ASSOCIATE may carry out the Exploration
           Operations in the areas it keeps pursuant to Clause 8 and THE
           ASSOCIATE shall be the only one responsible for the risks and costs of
           these activities, and, therefore, it shall have the complete and
           exclusive control of such activities without the maximum duration of
           the contract being modified for such cause.
 <PAGE>
                                                                                8
 CLAUSE 6 - SUPPLY OF INFORMATION DURING THE EXPLORATION
 6.1       ECOPETROL shall supply THE ASSOCIATE, whenever the latter may so
           request, with any information in its possession within the Contract
           Area. The costs of reproduction and supply of such information shall
           be charged to THE ASSOCIATE.
 6.2       During the Exploration Period, THE ASSOCIATE shall give ECOPETROL, as
           it is obtained and pursuant to ECOPETROL' s manual on information
           supply, all the geological and geophysical information, cores,
           magnetic tapes edited, processed seismic sections and all the
           information on the field supporting it, magnetic and gravimetric
           profiles, all in reproducible originals, copies of the geophysical
           reports, reproducible originals of all well logs drilled by THE
           ASOCIATE, including a final composite graph for each well and copies
           of the final drilling report that includes the analyses of core
           samples, the results of production tests and any other information
           related to the drilling, survey or interpretation of any nature done
           by THE ASSOCIATE for the Contract Area without any type of
           limitations. ECOPETROL is entitled to, at any time and by the
           procedures it considers appropriate, to witness all the operations and
           verify all information previously mentioned.
 6.3       The Parties agree that all geological, geophysical and engineering
           information obtained from the Contract Area in force during the
           development of this contract is confidential during the three (3)
           years following the date of acquisition or up to the termination of
           the contract, whatever happens first. The information made known is,
           but is not limited to seismic information, of potential methods, of
           remote sensors and geochemical, with its corresponding supports,
           surface and subsurface cartography, well reports, electric logs,
           formation tests, biostratigraphic, petrophysical and fluid analyses,
           and production background. Regardless of the confidentiality herein
           established, the Parties agree that in each case they may interchange
           with companies that are or not associated with ECOPETROL. It is
           understood that that agreed to herein shall take place without
           prejudice of the obligation to supply the Ministry of Mines and Energy
           with all information requested by it pursuant to the legal and
           Reglementary provisions in force. Nevertheless, it is understood and
           thus agreed, that the Parties may at their own discretion supply the
           information required by their affiliates, consultants, contractors,
           financial entities and that are required by the competent authorities
           with jurisdiction on the Parties or their affiliates, or by
           regulations of any stock markets in which the stocks of the Parties or
           corporations related are registered.
 6.4       Within the ninety (90) days following the date of termination of the
           drilling operations of each Exploration Well, THE ASSOCIATE shall
           inform ECOPETROL in writing of the condition of the corresponding
           well, its classification as to the results obtained (dry or discovery)
           and the type of fluids produced, if it is the case.
 CLAUSE 7 - BUDGET AND EXPLORATION PROGRAMS
 Observing that established in this contract, THE ASSOCIATE is obliged to prepare
 the programs, the chronogram of activities to be developed and the Budget to be
 executed in a short term (the following calendar year) and the vision for the
 following two (2) years with an estimated Budget, to carry out the exploration
 in the Contract Area. Such vision, programs, chronograms and Budgets
 <PAGE>
                                                                                9
 shall be presented for the first time to ECOPETROL, within the sixty (60) days
 following the date of the signing of this contract, and subsequently, December
 fifteen (15) of each year, the latest.
 Every semester THE ASSOCIATE shall present a technical and financial report to
 ECOPETROL, including the different exploratory activities performed, and the
 perspectives of the area based on the information obtained, the Budget assigned
 and the exploration costs incurred in up to the time of the presentation of the
 report, commenting in each case the causes that originated the main deviations
 presented. Upon request by ECOPETROL, THE ASSOCIATE shall supply the necessary
 explanations to the report, in meetings programmed for such purposed. The
 information presented by THE ASSOCIATE in the reports and the explanations to
 which the present Clause refers to, shall in any case be understood as accepted
 by ECOPETROL. The financial information shall be subject to auditing by of
 ECOPETROL pursuant to that established in Clause 22 of Annex "B" (Operating
 Agreement) of this contract.
 CLAUSE 8 - RESTITUTION OF AREAS
 8.1       Upon termination of the First Phase of three years of the Exploration
           Period or of such extensions thereof obtained by THE ASSOCIATE
           pursuant to Clause 5 (numeral 5.2), if a Commercial Field has been
           discovered and accepted by ECOPETROL in the Contract Area, said area
           shall be reduced to fifty percent (50%); two (2) years later the area
           shall be reduced to an extension equal to fifty percent (50%) of the
           remaining Contract Area and two (2) years later such area shall be
           reduced to the area of the Commercial Field or Fields under production
           or development plus one reserve zone of two and a half (2.5)
           kilometers wide surrounding each Commercial Field, and this shall be
           the only part of the Contract Area that shall be subject to the terms
           of this contract. Within the areas retained by THE ASSOCIATE pursuant
           to the present numeral, the Commercial Fields discovered shall be
           included.
 8.2       Notwithstanding the obligation to relinquish the areas referred to in
           Clause 8 (numeral 8.1), THE ASSOCIATE is not obliged to return the
           Commercial Fields that are under development or production, or in a
           Retention Period, including the reserve zones of two and a half (2.5)
           kilometers wide that surround such areas, except in the case in which
           by motives attributable to THE ASSOCIATE, the development or
           production operations are suspended continuously for more than one
           year without just cause, case in which such Commercial Fields shall be
           restituted to ECOPETROL, terminating the contract for said areas or
           part of the area. These stipulations are also applicable to the fields
           exploited under the modality of Sole Risk.
           Paragraph: To show just cause, THE ASSOCIATE must present to ECOPETROL
           the reasons and fundaments of the same for its acceptance.
 8.3       Retention Period: If THE ASSOCIATE has achieved the discovery of a Gas
           Field and presents a request for commerciality for such Field pursuant
           to that established in Clause 9 numeral 9.1, simultaneously with such
           application it may request ECOPETROL to issue a Retention Period,
           fully justifying the reasons to obtain such period.
 <PAGE>
                                                                               10
 8.3.1     The Retention Period must be requested by THE ASSOCIATE and granted by
           ECOPETROL previous to the date in which the last restitution of areas
           to which numeral 8.1 of this clause refers to. In the case in which
           the Retention Period is granted, it is understood that the term set
           forth in Clause 9 (numeral 9.1) for ECOPETROL to speak out with
           respect to the acceptance or not of the existence of the Commercial
           Gas Field shall be postponed for the same term of the Retention
           Period.
 8.3.2     The Retention Period may not exceed four (4) years. If the term
           initially granted as a Retention Period is insufficient, ECOPETROL,
           previous written and duly justified request by THE ASSOCIATE, may
           extend the Retention Period for an additional term, without having the
           sum of the initial retention period and its extensions exceed four (4)
           years. The Retention Period applies exclusively to the Gas Field area
           that ECOPETROL determines as capable of producing Hydrocarbons,
           including the reserve zone of two and a half (2.5) kilometers wide
           surrounding such area.
                            CHAPTER III - EXPLOITATION
 CLAUSE 9- TERMS AND CONDITIONS
 9.1       To initiate the Joint Operation hereunder, it is considered that the
           exploitation operations start on the date the Parties accept the
           existence of the first Commercial Field or upon compliance with the
           provisions of Clause 9 (numeral 9.5). The existence of a Commercial
           Field shall be determined by the drilling, by THE ASSOCIATE, within
           the proposed Commercial field of a number of Exploration Wells
           sufficiently to reasonably define the area and commerciality of the
           field capable of producing Hydrocarbons. If after evaluating the
           results obtained from the Discovery Wells, THE ASSOCIATE considers
           that it has discovered a possible Commercial Field, it must inform
           ECOPETROL in writing, supplying all the surveys on which this
           conclusion and the corresponding Development Plan are based on.
           ECOPETROL within the term of ninety (90) days as of the date in which
           THE ASSOCIATE turns in all the back-up information and makes a
           technical presentation to ECOPETROL, must accept or object the
           existence of the Commercial Field. ECOPETROL may request any
           additional information considered necessary within thirty (30) days
           following the date of submission of the first back-up information.
 9.2       Should ECOPETROL accept the existence of the Commercial Field, it
           shall, in this sense, notify THE ASSOCIATE within the term established
           in Clause 9 (numeral 9.1) specifying the area and the Production
           Objectives in the Commercial Field, and shall start to participate,
           under the terms of this contract, in the exploitation of the
           Commercial Field discovered by THE ASSOCIATE.
 9.2.1     ECOPETROL shall reimburse THE ASSOCIATE for fifty percent (50%) of the
           Direct Exploration Costs carried out by THE ASSOCIATE on its own
           account and risk within the Contract Area previous to the date of
           acceptance of the commerciality by ECOPETROL of each new Commercial
           Field discovered, pursuant to numeral 9.1 of the present Clause and
           that have not been previously charged to an other Field.
 9.2.2     The amount of such costs shall be determined in dollars of the United
           States of America, taking as a reference the date in which THE
           ASSOCIATE made such disbursements;
 <PAGE>
                                                                               11
           therefore, the costs incurred in Colombian pesos shall be liquidated
           at the market exchange rate in effect on such date, certified by the
           Superintendencia Bancaria or by the corresponding entity.
           Paragraph: Once the amount of the Direct Exploration Costs to be
           reimbursed in dollars of the United States of America is defined, this
           value shall be updated on a monthly basis pursuant to the average
           consumer index price of the industrialized countries, as of the date
           of its disbursement, to constant dollars on the date in which
           ECOPETROL begins the Reimbursement in the manner described on the
           Operating Agreement (Annex B) of this contract. The balances to be
           reimbursed shall be equally updated up to the date in which ECOPETROL
           fully reimburses its participation in the corresponding Commercial
           Field.
 9.2.3     The Reimbursement of the Direct Exploration Costs, pursuant to that
           established on Clause 9 (numerals 9.2.1) shall be made by ECOPETROL to
           THE ASSOCIATE, as of the moment in which the Field is put in
           production by the Operator, with the amount in dollars equivalent to
           fifty percent (50%) of its direct participation in the total
           production of the respective field, after deducting the corresponding
           percentage from the royalties.
           Paragraph: If concerning a Commercial Gas Field, such reimbursement
           shall be made by ECOPETROL to THE ASSOCIATE, as of the moment in which
           the Field is put under production by the Operator, with the amount in
           dollars equivalent to one hundred percent (100%) of its direct
           participation in the total production of such Field, after deducting
           the corresponding percentage from the royalties.
 9.3       If with the information supplied ECOPETROL cannot accept the existence
           of a Commercial Field to which Clause 9 (numeral 9.1) refers to, it
           may advise THE ASSOCIATE about the presentation and execution of a
           program for additional operations to demonstrate the existence of a
           commercial field, operations that will be carried out at the risk and
           cost of THE ASSOCIATE that may not require a term longer than two (2)
           years for its execution, and if it is the case, the Exploration Period
           for the Contract Area shall be extended automatically for a term equal
           to that already agreed on between the Parties, as necessary to execute
           the additional work in this Clause, but without prejudice of that
           stated with relation to the reduction of areas in Clause 8 (numeral
           8.1). THE ASSOCIATE may present and execute a work program that meets
           the objective required or submit for expert analysis the requirement
           of additional information, pursuant to Clause 28 of this contract. In
           the event that the definition of the expert analysis is favorable to
           ECOPETROL, THE ASSOCIATE must fulfill the requirements and once again
           submit the studies of commerciality and the revised Development Plan
           to ECOPETROL for its consideration. In the event that the definition
           of the expert analysis is favorable to THE ASSOCIATE, it is understood
           that ECOPETROL has the necessary information and as a consequence, the
           term of ninety (90) days to which clause 9.1 refers to, to accept or
           to object the existence of a Commercial Field shall begin on the date
           in which ECOPETROL receives the report from the experts.
 9.4       If, after the completion of the additional work or the disagreement
           solved by the expert analysis to which the previous numeral refers to,
           ECOPETROL accepts the existence of the Commercial Field to which
           Clause 9 (numeral 9.1) refers to, it will start to participate in the
           development operations of the field above mentioned in the terms
           established in this contract and shall reimburse THE ASSOCIATE as set
           forth in Clause 9 (numerals 9.2.2 and
 <PAGE>
                                                                               12
           9.2.3) for fifty percent (50%) of the cost of the additional work
           requested and referred to in Clause 9 (numeral 9.3) and the work
           executed shall become the property of the Joint Account.
 9.5       Modality of Sole Risk: If ECOPETROL does not accept the existence of a
           Commercial Field, after having performed the additional work referred
           to in Clause 9 (numeral 9.3), THE ASSOCIATE shall be entitled to
           execute such work as it may consider necessary in or to exploit such
           field and to reimburse itself two hundred percent (200%) of the total
           cost of the work executed at its own account and risk in the such
           field and up to fifty percent (50%) of the Direct Exploration Costs
           carried out by THE ASSOCIATE before the date of the presentation of
           the commerciality surveys of such field. For the effects of this
           Clause the reimbursement shall be done with the value of the produced
           Hydrocarbons, less the royalties referred to in Clause 13, deducting
           the costs of production, gathering, transportation and sale. If THE
           ASSOCIATE abides to the modality of sole risk, it is understood that
           the term of the exploitation begins on the date in which ECOPETROL
           informs THE ASSOCIATE of the nonexistence of a Commercial Field. For
           the purposes of liquidation of the value in dollars of the
           disbursements done in pesos, it shall be liquidated at the
           representative market rate certified by the Superintendencia Bancaria
           or by the corresponding authority, on the date in which THE ASSOCIATE
           has made such disbursements. For the purpose of this Clause, the value
           of each barrel of Hydrocarbons produced in such Field during a
           calendar month shall be the average price per barrel that THE
           ASSOCIATE receives from the sales of its participation in the
           Hydrocarbons produced in the Contract area during the same month. With
           reference to the reimbursement of the Direct Exploration Costs, that
           established in paragraph of clause 9 (numeral 9.2.3) shall be applied.
           When THE ASSOCIATE has reimbursed itself of the percentage established
           in the present clause, all drilled wells, installations and all types
           of goods acquired by THE ASSOCIATE for the exploitation of the field
           and paid for as indicated in the present clause, shall become the
           property of a Joint Account without any cost, previous the acceptance
           by ECOPETROL to participate in the development of such field.
 9.6       ECOPETROL may, at any time, start to participate in the operation of
           the field discovered and developed by THE ASSOCIATE without prejudice
           to THE ASSOCIATE' s right to reimburse itself for the investments it
           made at its expense, in the form and percentage stipulated in Clause 9
           (numeral 9.5). Once THE ASSOCIATE is reimbursed, ECOPETROL shall enter
           to participate in the economic results of the wells developed at the
           exclusive expense of THE ASSOCIATE.
 9.7       The demarcation of the boundaries of a Commercial Field shall take
           into consideration all the geological and geophysical information and
           that of the wells drilled within said field or related to the same.
 9.8       If after the commerciality of one or more fields is accepted, THE
           ASSOCIATE continues to fulfill the exploratory obligations established
           in Clause 5, it may continue to simultaneously carry out the
           exploitation of such fields before the expiration of the Exploration
           Period established in Clause 4, but only as of the date of its
           termination shall the Exploitation Period begin. When concerning Gas
           Fields, and ECOPETROL has granted a Retention
 <PAGE>
                                                                               13
           Period, the Exploitation Period for each Field shall begin on the date
           of expiration of the respective Retention Period.
 9.9       If as a result of the drilling of Exploratory Wells, after confirming
           the existence of a Commercial field, THE ASSOCIATE proves the presence
           of additional accumulations of Hydrocarbons associated to such Field,
           it must request ECOPETROL to extend the area of the Commercial Field
           and its commerciality, following the procedure set forth in Clause 9
           (numeral 9.1). If ECOPETROL accepts its commerciality, it shall
           reimburse THE ASSOCIATE fifty percent (50%) of the Direct Exploration
           Costs exclusively related with the expansion of the area of the
           Commercial Field, in the terms established in numerals 9.2.2 and
           9.2.3. If ECOPETROL does not accept the commerciality, THE ASSOCIATE
           is entitled to reimburse itself up to two hundred percent (200%) of
           the total cost of the work executed on its own cost and risk for the
           exploitation of the Exploratory Wells that have resulted productive
           and up to fifty percent (50%) of the direct Exploration Costs carried
           out by THE ASSOCIATE exclusively related to the expansion of the area
           requested before the date in which ECOPETROL notifies on the same.
           Such reimbursement shall be done with the production originated from
           the Exploratory Wells that have resulted productive, after deducting
           royalties, following the procedure set forth in Clause 21 (numeral
           21.2) up to the percentages herein defined.
 CLAUSE 10 - OPERATOR
 10.1      The Parties agree that HARKEN DE COLOMBIA LIMITED is the Operator and,
           as such, with the limitations set forth in this contract, shall have
           the control of all the operations and activities it may consider
           necessary for an efficient technical and economic development of the
           exploitation of the hydrocarbons found within the area of the
           Commercial Field. They also agree that, nevertheless that in this
           contract - executed for the commercial purposes established in Clause
           1 of the same, HARKEN DE COLOMBIA LIMITED is the Operator, it is
           understood by the Parties, and thus determined, that for all labor
           legal effects, HARKEN DE COLOMBIA LIMITED does not act as a
           representative of the Parties, but as an only and true employer of the
           workers he contracts for the operation of the Commercial Field and, as
           a consequence, shall be responsible for the labor obligations that
           arise from the respective relations or work contracts, such as salary
           payments and social benefits, para-fiscal contributions, affiliation
           and payment of bids or contributions for pensions, health and
           professional risks to the Sistema de Seguridad Social Integral, to
           which Law 100 of 1993 refers to and its Reglementary decrees or those
           regulations that substitute or modify it.
 10.2      The Operator has the obligation to carry out all of the development
           and production operations pursuant to the standards and practices
           generally accepted by the industry using the best technical methods
           and systems required for the economic and efficient exploitation of
           the Hydrocarbons and fulfilling the legal and regulatory provisions on
           the issue. Also, he must present on time, to the parties, the reports
           and documents mentioned in the contract, as well as any other
           information required by the Executive Committee with respect to the
           Joint Account and/or Operation.
 10.3      Due to the afore mentioned, and in view that for the execution and
           fulfillment of the operation of the Commercial Field, HARKEN DE
           COLOMBIA LIMITED shall perform all the activities with its own
           resources, with liberty and technical and directive autonomy, for all
           the
 <PAGE>
                                                                               14
           purposes of this contract, such Operator shall be considered an entity
           different from The Parties hereto as well as for the purposes of the
           implementation of civil, labor and administrative legislation and for
           the Operator's relations with the personnel at his service, as set
           forth in clause 32.
 10.4      The Operator shall have the right to resign as such, by written
           notification to the Parties six (6) months in advance of the effective
           date of such resignation. The Executive Committee shall then assign a
           new Operator pursuant to Clause 19 (numeral 19,3,5). In case the
           Operator assigned by the Executive Committee is a third person
           different from the Parties, a contract must be executed between the
           Parties and the new Operator.
 10.5      The Operator shall carry out the operations described in this contract
           in a diligent, responsible, efficient and technically and economically
           adequate manner, being understood that at no time shall he be
           responsible for mistakes in criteria, or for losses or damages that
           are not the result of a serious fault by the Operator.
 10.6      The Operator shall have the right to execute any type of work by means
           of contractors, subject to the faculty that the Executive Committee
           has, pursuant to Clause 11 (numeral 11.1). To fulfill that herein
           established, the Operator shall carry out the contracting operations
           following the procedure described in Annex "B" and subject to the
           principles of good faith, transparency, economy, equity,
           responsibility, planning, quality, celerity and social and
           environmental responsibility that must rule in the contracting.
 CLAUSE 11 - EXPLOITATION PROGRAMS AND BUDGETS
 11.1      Within the three (3) months following the acceptance of a Commercial
           Field in the Contract Area, the Operator shall present to the parties,
           a proposal for projects, programs and budget for the Development Plan
           of the commercial field for the remaining of the corresponding
           Calendar year, to be agreed on by the Executive Committee. In case
           there are less than six months and a half (6 - 1/2) for the expiration
           of such year, the Operator shall prepare and present a proposal for
           projects, programs and Budget for the following calendar year, within
           a term of three (3) months.
 11.1.     The projects, programs and the Budget contained in the Development
           Plan of the Commercial Field shall be checked and adjusted on a yearly
           basis and presented by the Operator to the Parties during the month of
           May of each calendar year, for which the Operator shall send his
           proposal within the first ten (10) days of the month of May. Within
           the twenty (20) days following the receipt of the proposal of the
           projects, programs, and Budget of the Development Plan of the
           Commercial Field, the Parties shall inform the Operator in writing on
           the changes they wish to propose. When this occurs, the Operator shall
           consider the observations and proposed reforms made by the Parties for
           the elaboration of the revised Development Plan, that shall be
           submitted for final approval of the Executive Committee, at the
           ordinary meeting during the month of July of each year. In case the
           total Budget of the Commercial Field has not been approved before the
           month of July, those aspects of the Budget of the Commercial Field on
           which an agreement has been reached, shall be approved by the
           Executive Committee, and those aspects not approved shall be submitted
           immediately to the Parties, for study and final decision, as set forth
           in Clause 20.
 <PAGE>
                                                                               15
 11.2.     The Parties may propose additions or revisions to the projects,
           programs and the annual Budget approved for each Commercial Field,
           but, except in cases of emergency, these must not be formulated with a
           frequency of less than three (3) months. The Executive Committee shall
           decide on the proposed additions or revisions at a meeting called
           within thirty (30) days following the presentation of the same.
 11.3.     The main objectives of the projects, programs and Budgets are:
 11.3.1    Determine the operations to be carried out and the expenses and
           investments (Budget) that the Operator is authorized to execute in
           each Commercial field during the following calendar year.
 11.3.2    Maintain a vision of the development of each field in a horizon of
           medium and long term.
 11.4      The projects, programs and annual Budget approved by the Executive
           Committee and contained in the Development Plan of each Commercial
           Field constitute the work plan shown and the expenses and investments
           estimated to be carried out by the Operator in the different aspects
           of the operation, such as:
 11.4.1    Capital investments in production: drilling for the development of
           Reservoirs, well workover or recovery, and specific production
           constructions.
 11.4.2    General construction and equipment: industrial and camp facilities,
           transportation equipment, drilling and production equipment. Other
           construction and equipment.
 11.4.3    Maintenance and operating expenses: production expenses, geological
           expenses, administration expenses for the operation.
 11.4.4    Working capital requirements.
 11.4.5    Funds for contingencies
 11.5      The Operator shall make all expenditures and investments and shall
           carry out the development and production operations set forth in the
           projects, programs and annual Budgets approved in the Development Plan
           for each Commercial Field referred to in Clause 11 (numeral 11.1),
           pursuant to the Operating Agreement (Annex B) that is part of this
           contract, without exceeding the total Budget for each year, except by
           authorization of the parties in special cases.
 11.6      The Operator is authorized to carry out expenditures not contemplated
           expressly in the Budget of each Commercial field and chargeable to the
           Joint Account, without previous authorization of the Executive
           Committee, in the event of emergency measures aimed at safeguarding
           personnel or the property of the Parties, emergency expenses
           originating in fires, floods, storms or other disasters; emergency
           expenses essential for the operation and maintenance of the production
           facilities, including maintenance of the wells in a condition to
           produce with a maximum efficiency; emergency expenses essential for
           the protection and preservation of materials and equipment necessary
           in the operations. In such cases, the Operator shall call the
           Executive Committee to a special meeting as soon as possible, to
           obtain their approval in order to continue with the emergency
           measures.
 <PAGE>
                                                                               16
 11.7      From the amount of the expenditures incurred in by and the contracts
           executed by the Operator for amounts that exceed the annual Budget
           approved by the Executive Committee for each Commercial Field, as set
           forth in Clause 19 (numeral 19.3.9), without them having been
           opportunely authorized by the Executive Committee, except the
           assumptives set forth in Clause 11 (numeral 11.6), the Operator shall
           be the only one responsible, who shall assume the totality of the
           corresponding value. When the expense or contract in question is
           confirmed by the Executive Committee, the corresponding value shall be
           paid to the operator, pursuant to the rules defined by the Executive
           Committee. In case in which the expenditure or contract is not
           accepted by the Executive Committee, the Operator, if possible, may
           withdraw the good in question reimbursing the Parties for any cost
           that its withdrawal may cause them. When it is impossible for the
           Operator to withdraw such goods, or he rejects doing so, the benefit
           or patrimonial increase resulting from these expenses or contracts,
           shall belong to the Parties in proportion to their Interest in the
           Operation.
 CLAUSE 12 - PRODUCTION
 12.1      Whenever necessary, the Operator shall determine, with the approval of
           the Executive Committee, the Maximum Efficiency Rate (MER) for each
           commercial Field. This Maximum Efficiency Rate (MER) shall be the
           maximum producing rate of Hydrocarbons that may be extracted from a
           Reservoir for the purpose of obtaining a maximum economic benefit in
           the final recovery of Reservoirs. In agreement with the economic and
           engineering principles and the practices and procedures generally used
           and in use in the international oil industry, in conditions and
           circumstances similar to those experienced in the activities under
           this contract. The estimated production must be adjusted as necessary
           to compensate the real or anticipated conditions of the operation,
           such as wells under repair that are not producing, limitations in the
           capacity of the collecting lines, in the pumps, in the separators, in
           the tanks, in the pipelines and in other facilities.
 12.2      The Operator shall determine periodically, at least once a year, with
           the approval of the Executive Committee, the area deemed capable of
           producing Hydrocarbons in a commercial quantity in each Commercial
           Field.
 12.3      The Operator shall prepare and deliver to each Party, at regular three
           (3) month intervals, a program showing each Party's share of
           production, and another one showing the distribution of each Party's
           production for the following six (6) months. The forecast for the
           production must be based on the Maximum Efficiency Rate (MER,) as set
           forth in Clause 12 (numeral 12.1) and adjusted to each party's rights
           according to this contract. The Production Distribution Program shall
           be determined based on each party's periodic requests, and, set forth
           in Clause 14 (numeral 14.2) with the corrections deemed necessary to
           ensure that none of the Parties, while being able to withdraw, will
           receive less than the quantity to which it is entitled to under
           provisions of Clause 14 and without prejudice to the stipulations of
           Clauses 21 (numeral 21.2) and 22 (numeral 22.5).
 12.4      If either of the Parties foresees a reduction in its capacity to
           receive Hydrocarbons compared to the forecast given to the Operator,
           the Party must inform the Operator as soon as possible, and if such
           reduction is due to an emergency situation, the Party shall inform the
           Operator within the twelve (12) hours following the occurrence of the
           event that causes
 <PAGE>
                                                                               17
           the reduction. As a consequence, such Party shall give the Operator a
           new receipt schedule based on the appropriate reduction.
 12.5      The Operator may use the Hydrocarbons that are consumed in the
           development of the production operations in the Contract Area and
           these consumptions shall be exempt from the royalties to which Clause
           13 (numeral 13.1) refer to.
 CLAUSE 13 - ROYALTIES
 13.1      For the payment of the royalties for the exploitation of the
           nationally owned Hydrocarbons, the Operator shall give ECOPETROL the
           percentage of the production established by Law. The delivery of this
           production shall be carried at the same place and time in which the
           Parties distribute the production that corresponds them pursuant to
           Clause 14 of this contract. In the case of Fields under exploitation
           in the modality of Sole Risk, THE ASSOCIATE shall give ECOPETROL the
           percentage of the production that corresponds to the royalties in the
           place agreed on by the Parties.
 13.2      From the percentage of the production given to ECOPETROL in the terms
           of the previous numeral, ECOPETROL, in the way and terms established
           by law, shall pay those entities mentioned by law the royalties that
           are caused in favor of the Nation on the total of the production of
           the Field and, in no case, shall THE ASSOCIATE be responsible for any
           type of payment before these entities.
 CLAUSE 14 - DISTRIBUTION AND AVAILABILITY OF THE HYDROCARBONS
 14.1      The Hydrocarbons produced, except those that have been used in benefit
           of the operations of this contract and those that are inevitably
           wasted in these functions, shall be transported to the jointly owned
           tanks or to other measuring facilities agreed upon by the Parties. If
           there is no agreement, to the measuring site nearest to the control
           site established by the Ministry of Mines and Energy. The Hydrocarbons
           shall be measured pursuant to the regulations and methods accepted by
           the oil industry, and based on this measurement, the volumes to which
           Clause 13 refer to shall be determined. As of this moment, the
           remaining Hydrocarbons shall be the property of each Party in the
           proportions specified in this contract.
 14.2 Distribution of Production
 14.2.1    After having deducted the percentage that corresponds to the
           royalties, the rest of the Hydrocarbons produced by each Commercial
           Field are the property of the Parties in the proportion of fifty
           percent (50%) for ECOPETROL and fifty percent (50%) for THE ASSOCIATE,
           until the cumulative controlled production of the corresponding
           Commercial Field reaches the amount of sixty (60) million barrels of
           liquid Hydrocarbons or the amount of four hundred twenty (420) cubic
           gigafeet of gaseous Hydrocarbons to standard conditions, what ever
           occurs first (1 cubic gigafoot = 1 X 109 cubic feet).
 14.2.2    Independently from the classification of the Commercial Field given by
           ECOPETROL in the definition of commercialization, exceeding the limits
           set forth in numeral 14.2.1, the distribution of the production of
           each Commercial Field (previous the deduction of the
 <PAGE>
                                                                               18
           percentage corresponding to royalties) is the property of the Parties
           in the proportion that results from applying factor R as follows:
 14.2.2.1  If the Hydrocarbon that reached first the limit established in numeral
           14.2.1 of the present Clause was the liquid Hydrocarbon, the following
           table shall be applied:
 R  FACTOR        Distribution of Production After Royalties (%)
                           ASSOCIATE           ECOPETROL
 0.0 to 1.0                   50                 50
 1.0 to 2.0                   50/R            100 - 50 R
 2.0 or more                  25                 75
 14.2.2.2. If the Hydrocarbon that reached first the limit established in numeral
           14.2.1 of the present Clause was the gaseous Hydrocarbon, the
           following table shall be applied:
 R  FACTOR        Distribution of Production After Royalties (%)
                           ASSOCIATE          ECOPETROL
 0.0 to 2.0                   50                  50
 2.0 to 3.0                   50/(R-1)        100 - [50 /(R-1)]
 3.0 or more                  25                  75
 14.2.3    For the effects of the previous tables, factor R shall be defined as
           the relation of cumulative incomes, expressed in constant terms, over
           the cumulative expenses, equally expressed in constant terms,
           corresponding to THE ASSOCIATE for each Commercial Field in the
           following terms:
                                        IA
                          R = ---------------------------
                                  ID + A - B + GO
           Where:
           IA (Cumulative Income of THE ASSOCIATE): Is the valuation of the
           cumulative incomes corresponding to the volume of THE ASSOCIATE' s
           Hydrocarbons produced, after royalties, at the reference priced agreed
           on by the Parties, excluding re-injected Hydrocarbons in the Fields in
           the Contract Area, those consumed in the operation and the flared gas.
           The average reference price of the Hydrocarbons shall be determined by
           mutual agreement between the Parties.
           To determine the cumulative incomes, the Monthly Incomes shall be
           taken as a base, which shall be determined as a result of multiplying
           the monthly average reference price by the production of the month
           pursuant to the formats established for such effect by the Ministry of
           Mines and Energy.
 <PAGE>
                                                                               19
           ID (Cumulative Development Investments): Are fifty percent (50%) of
           the Cumulative Development Investments approved by the Executive
           Committee of the Association for each Commercial Field. The cumulative
           Development Investments done previous to the date of the initiation of
           the exploitation defined by the Ministry of Mines and Energy for the
           respective Field, shall be adjusted up to the present date in the same
           manner in which the Direct Exploration Costs are adjusted in the
           Paragraph of Clause 9 (numeral 9.2.2.).
           A: Are the Direct Exploration Costs in which THE ASSOCIATE has
           incurred in, pursuant to Clause 9 of this contract and adjusted
           pursuant to that established in Paragraph of clause 9 (numeral 9.2.2)
           B: Is the cumulative Reimbursement of the Direct Exploration Costs,
           previously mentioned, pursuant to Clause 9 of this contract.
           GO: (Cumulative Operation Expenses): Are the cumulative operation
           expenses approved by the Executive Committee of the Association, in
           the proportion that corresponds THE ASSOCIATE, plus the cumulative
           transportation costs of THE ASSOCIATE. As transportation costs it is
           understood, the investment and operation expenditures for the
           transportation of Hydrocarbons produced in the Commercial Fields
           located in the Contract Area, from it to the port of export or site
           where it is agreed to take the price to be used in the calculation of
           incomes IA. Such transportation costs shall be determined by the
           parties in mutual agreement once the exploitation stage of the Fields
           begins, which commerciality has been accepted by ECOPETROL. Within the
           Operation Expenses the Special Contributions are included or those
           similar that have direct application on the production of Hydrocarbons
           in the Contract Area.
           All values that, with posteriority to the date of initiation of the
           exploitation defined by the Ministry of Mines and Energy, included in
           the determination of factor R shall be taken in current dollars.
           For such effect, the expenses in pesos must be converted into dollars
           at the market rate certified by the Superintendencia Bancaria or by
           the corresponding authority, in charge on the date in which the
           corresponding disbursements have been done.
 14.2.4    Calculation of factor R: The distribution of the production based on
           factor R shall begin to be applied as of the first day of the third
           calendar month after which the cumulative production of each
           Commercial Field reaches the amount of sixty (60) million barrels of
           liquid Hydrocarbons or to the amount of four hundred twenty (420)
           cubic gigafeet of gaseous Hydrocarbons at standard conditions,
           pursuant to numeral 14.2.1 of this clause.
           The calculation of factor R for each Commercial Field shall be done
           based on the accounting closing corresponding to the calendar month in
           which the cumulative control production of sixty (60) million barrels
           of liquid Hydrocarbons was reached or the amount of four hundred
           twenty (420) cubic gigafeet of gaseous Hydrocarbons at standard
           conditions, pursuant to numeral 14.2.1.
           The resulting distribution of the production shall be applied until
           June 30 of the following year. As of that moment, the distribution of
           the production with the application of factor R shall be done in one
           year terms (from July 1 to June 30), over its liquidation, based on
           the
 <PAGE>
                                                                               20
           cumulative values to December 31 of the year immediately preceding
           pursuant to the corresponding accounting closing.
 14.3      In addition to the tanks and other jointly owned facilities, each
           Party shall have the right to build its own production facilities in
           the Contract Area for its own and exclusive use in compliance with the
           legal regulations. The transportation and delivery of Hydrocarbons by
           each Party to the pipeline and to other storage facilities that are
           not jointly owned shall be done on the sole account and risk of the
           Party that receives the Hydrocarbons.
 14.4      When production is obtained in places not connected by pipelines, the
           Parties may agree to install pipelines up to a point in which the
           Hydrocarbons may be sold, or to a place that connects with the
           pipeline. If the parties agree on the construction of such pipelines,
           they shall enter the contracts they consider suitable for this purpose
           and appoint the Operator pursuant to the legal provisions in force.
 14.5      Each Party shall be the owner of the Hydrocarbons produced and stored
           as a result of the Operation hereunder and that are made available to
           it pursuant to the provisions of this contract, and on its account
           each Party must receive them in kind or sell them or dispose of them
           separately, according to that established in Clause 14 (numeral 14.3).
 14.6      Should any of the Parties be unable for any reason to dispose of or
           separately withdraw from the tanks Jointly Account all or part of the
           Hydrocarbons it is entitled to pursuant to this contract, the
           following procedure must be followed:
 14.6.1    If ECOPETROL is the Party unable to withdraw, in all or in part, its
           quota of Hydrocarbons (share plus royalties), pursuant to clause 12
           (numeral 12.3), the Operator may continue to produce the field and
           delivering to the ASSOCIATE, in addition to the portion that the quota
           of THE ASSOCIATE represents in the operation on the basis of one
           hundred percent (100%) of the MER, all those Hydrocarbons that THE
           ASSOCIATE decides to and in the capacity of withdrawing up to a limit
           of one hundred percent (100%) of the MER, crediting ECOPETROL for
           subsequent delivery, the volume of Hydrocarbons that ECOPETROL had the
           right to withdraw but that did not do so. With regard to the not
           withdrawn volume of Hydrocarbons to which ECOPETROL is entitled to
           during the month for royalties, THE ASSOCIATE, at the request of
           ECOPETROL, shall pay ECOPETROL in dollars of the United States of
           America, the difference that exists between the amount of Hydrocarbons
           that for the concept of royalties ECOPETROL has lifted and the amount
           of Hydrocarbons that it is entitled to for the concept of the
           royalties to which Clause 13 refers to, being understood that any
           withdrawal of Hydrocarbons done by ECOPETROL shall be applied, in
           first place to royalty payment in kind, and subsequently, any
           additional withdrawals of Hydrocarbons performed shall be applied to
           the share that it is entitled to pursuant to Clause 14 (numeral 14.2).
 14.6.2    Should THE ASSOCIATE be the Party unable to withdraw, in all or in
           part, its quota assigned under Clause 12 (numeral 12.3), the Operator
           shall deliver to ECOPETROL, on the basis of one hundred percent (100%)
           of MER, not only the share and the quota that corresponds to
           ECOPETROL, but also the Hydrocarbons that ECOPETROL is in the capacity
           of withdrawing up to a limit of one hundred percent (100%) of MER,
           accrediting THE ASSOCIATE for its subsequent delivery, the part that
           corresponds to its quota and that it has been unable to withdraw.
 <PAGE>
                                                                               21
 14.7      When both parties are in the capacity to receive the Hydrocarbons
           assigned under Clause 12 (numeral 12.3), the Operator shall deliver to
           the Party that was previously unable to receive its quota of the
           production and, upon such Party's request, besides its share in the
           operation, a minimum of ten percent (10%) per month of the production
           that corresponds to the other Party on a monthly basis and, by mutual
           agreement, up to one hundred percent (100%) of the quota that was not
           received, up to the time in which the total amounts that were credited
           to the Party that was unable to received its Hydrocarbons, are
           cancelled.
 14.8      Without prejudice of the legal provisions that rule the mater, each
           Party shall be free, at any moment, to sell or export its quota of the
           Hydrocarbons obtained, as agreed to in this contract, or to dispose of
           the same in any manner.
 CLAUSE 15 - USE OF THE ASSOCIATED NATURAL GAS
 In the case in which one or more fields of associated natural gas are
 discovered, the Operator shall, within the three (3) years following to the date
 of the initiation of the exploitation of the Field defined by the Ministry of
 Mines and energy, submit a project on the use of the Natural Gas for benefit of
 the Joint Operation. The Executive committee shall approve the project and, if
 necessary, decide on the chronogram for the execution thereof. If the Operator
 fails to present any project within the three (3) following years or does not
 execute the project previously approved, within the time limits set by the
 Executive Committee, ECOPETROL may take, free of charge, for itself, all the
 associated natural gas available from the Reservoirs in exploitation, which is
 not required for the efficient exploitation of the Field.
 CLAUSE 16 - UNIFICATION
 When an economically exploitable Reservoir extends continuously into other area
 or areas outside the Contract Area, the Operator shall implement, in agreement
 with the Parties and with any other interested parties, upon approval of the
 Ministry of Mines and Energy, a unified exploitation program that meets the
 Hydrocarbons exploitation engineering techniques.
 CLAUSE 17 - SUPPLY OF INFORMATION AND INSPECTION DURING THE EXPLOITATION
 17.1      The Operator shall deliver to the parties, as they are obtained,
           reproducible originals (sepias), and copies of the electric,
           radioactive and sonic logs of the wells drilled, historical records,
           core analysis, cores, production tests, reservoir surveys and other
           relevant technical information, as well as all routine reports made or
           received in connection with the operations and activities carried out
           in the Contract Area.
 17.2      Each Party, at its own cost, expense and risk, shall have the right to
           inspect, through authorized representatives, the wells and the
           facilities in the Contract Area and the activities related thereto.
           Such representatives shall have the right to examine cores, samples,
           maps, logs for wells drilled, liftings, books and any other source of
           information connected with the performance of this contract.
 17.3      To enable ECOPETROL to comply with the provisions of Clause 29, the
           Operator shall prepare and deliver to ECOPETROL all reports required
           by the National Government.
 <PAGE>
                                                                               22
 17.4      The information and data connected with exploitation operations shall
           be treated as confidential, in the same way as set forth in Clause 6
           (numeral 6.3) of this contract.
                         CHAPTER IV - EXECUTIVE COMMITTEE
 CLAUSE 18 - CONSTITUTION
 18.1      Within the thirty (30) calendar days from the acceptance of the first
           commercial Field, each Party must appoint a representative and
           corresponding first and second alternates, who shall form the
           Executive Committee, notifying the other Party in writing of the names
           and addresses of its representatives and alternates. Each Party may
           replace its representative or alternates at any time, but shall give
           written notice thereof to the other Party. The vote or decision of the
           principal representative of each Party shall be binding upon such
           Party. If the principal representative of any of the Parties is unable
           to attend a Committee meeting, the alternate, in its order first or
           second, shall attend, and shall have the same authority as the
           principal.
 18.2      The Executive Committee will hold ordinary meetings during the months
           of March, July and November, during which the exploitation program
           carried out by the Operator shall be reviewed as well as the
           development program and the immediate plans. Every year, at the July
           ordinary meeting, the Operator shall present the Executive Committee
           with the annual operating program and the investment and expenses
           Budget for each Commercial Field, for the next calendar year, and if
           it is the case, the Revised Development Program.
 18.3      The Parties and the Operator may request a special Executive Committee
           Meeting to analyze specific conditions of the operation. The
           representative of the interested Party shall notify the date of the
           meeting and the issues to be discussed with a ten (10) calendar day's
           notice. Any issue not included in the agenda of the meeting may be
           discussed during the meeting, upon acceptance of the representatives
           of the Parties on the Committee.
 18.4      Each Party's representative shall have a vote in all matters discussed
           in the Executive Committee, equivalent to the percentage of that
           Party's total Interests in the Joint Operation. However, the decisions
           of the Executive Committee on the issues set forth in numerals 19.3.4
           through 19.3.9 of Clause 19 of this contract, shall be adopted by a
           unanimous vote of the Parties.
           Any decisions taken by the Executive Committee, set forth in the
           procedure established in this clause, shall be binding and final upon
           the Parties and the Operator.
 CLAUSE 19 - FUNCTIONS
 19.1      The representatives of the Parties shall form the Executive Committee
           which shall have full authority and responsibility to establish and
           adopt exploitation, development and operations programs and Budgets in
           relation with this contract. A representative of the Operator shall
           attend the meetings of the Executive Committee.
 <PAGE>
                                                                               23
 19.2      The Executive Committee shall designate a Secretary for each session.
           The Secretary shall take full, detailed records and minutes of all the
           meetings, including a summary of the discussions and decisions taken
           by the Committee. The Minutes shall be approved and signed by the
           representatives of the Parties within the ten (10) working days
           following the adjournment of the meeting and delivered to the Parties
           as soon as possible.
 19.3      The responsibilities of the Executive Committee are, amongst others,
           as follows:
 19.3.1    Adopt its own regulations.
 19.3.2    Decide on those issues that the Operator submits for its
           consideration.
 19.3.3    Supervise the performance of the Joint Account and of the Joint
           Operation
 19.3.4    Create the necessary sub-committees and establish the functions they
           must perform under its direction.
 19.3.5    Appoint the Operator in case of resignation or discharge, and dictate
           the regulations that the Operator must fulfill when he is a third
           person different from the Parties, definitely stating the motives for
           his discharge.
 19.3.6    Appoint an External Auditor of the Joint Account.
 19.3.7    Approve or reject the Development Plans and any subsequent
           modification or revision.
 19.3.8    Determine the rules and policies on expenditures.
 19.3.9    Approve or reject the projects, programs and the annual Budget of each
           Commercial Field and authorize extraordinary expenditures not included
           in the approved Budgets.
 19.3.10   In general, to carry out all the functions authorized in this contract
           that do not correspond to the Operator, to any other entity or person
           under the specific clause hereof or under a legal or regulatory
           provision.
 CLAUSE 20 - DECISION IN CASE OF DISAGREEMENTS
 20.1      Any disagreement that cannot be solved in the Executive Committee,
           shall be directly submitted to the highest ranking executive of each
           of the Parties resident in Colombia, in order to reach a joint
           decision. If within the sixty (60) calendar days following the
           submission of the consultation, the Parties reach an agreement or a
           decision on the issue under discussion, they shall so advise the
           Operator, who, within the fifteen (15) calendar days following the
           receipt of the communication, shall call the Executive Committee to an
           extraordinary meeting, during which the agreement or decision adopted
           shall be approved.
 20.2      If within the sixty (60) calendar days following to the date of the
           presentation of the consultation to the highest ranking executive of
           each of the Parties resident in Colombia, the Parties fail to agree on
           the issue, the procedures set forth in Clause 28 of this contract must
 <PAGE>
                                                                               24
           be followed, except if concerning issues related to the operations, in
           which case they may be executed pursuant to Clause 21.
 CLAUSE 21 - OPERATIONS UNDER RISK OF ONE OF THE PARTIES
 21.1      If at any time one of the Parties wishes to drill an Exploitation Well
           not approved in the operations program, it shall notify the other
           Party written notice not less than thirty (30) calendar days in
           advance of the next Executive Committee meeting, of its wish to drill
           such well, including information such as location, recommendation to
           drill, and estimated depth and costs. The Operator shall include such
           a proposal among the issues to be discussed in the next Executive
           Committee Meeting. If such proposal is approved by the Executive
           Committee such well shall be drilled at the expense of the Joint
           Account. If such proposal is not accepted by the Executive Committee,
           the Party wishing to drill such well, hereinafter called participating
           Party, shall have the right to drill, complete, produce or abandon
           such well at its sole cost and risk. The Party not wishing to
           participate in the previous operation shall be called the
           non-participating Party. The participating Party must begin the
           drilling of such well within one hundred eighty (180) days following
           its rejection by the Executive Committee. If the drilling is not
           commenced within said period, it must again be submitted to the
           Executive Committee for its consideration. Upon request of the
           participating Party, the Operator shall drill the previously mentioned
           well on account and risk of the participating Party, provided that by
           judgment of the Operator such operation does not interfere with the
           normal development of the operations of the field, upon advance
           payment to the Operator by the Participant Party of such amounts as
           the Operator may deem necessary in order to drill. If said well is
           unable to be drilled by the Operator without interfering in the normal
           development of the operations, the participating Party shall have the
           right to drill such well directly or through a competent service
           company and, in this case, the participating Party shall be
           responsible for such operation, without interfering with the
           development of the normal operations in the Field.
 21.2      If the well referred to in Clause 21 (numeral 21.1) is completed as a
           producing well, it shall be administered by the Operator and the
           production of such well, after deducting the royalties referred to in
           Clause 13, it shall become the property of the participating Party,
           who shall pay for all the operation costs of such well until the net
           production value, after deducting the production costs, gathering,
           storage, transportation and similar costs, as well as sale costs, is
           equal to two hundred percent (200%) of the drilling and completing
           cost of such well, which thereupon and for the purposes of this
           contract shall become the property of the holders of the Joint Account
           in the proportion established, as if it had been drilled with the
           approval of the Executive Committee for the account of both Parties;
           for such purpose the investments done and the costs incurred, in the
           exploitation of this well shall become part of Factor R of the
           Commercial Field. For the purpose of the present Clause, the value of
           each barrel of Hydrocarbons produced in such well, during a calendar
           month, before deducting the previously mentioned costs, shall be the
           reference price agreed by the Parties.
 21.3      If at any time one of the Parties decides to workover, deepen up to
           the Production Objectives or plug a well that is not in commercial
           production or a dry well drilled by the Joint Account, and if such
           operations have not been included in a schedule approved by the
           Executive Committee, such Party shall notify the other Party of its
           intention to workover,
 <PAGE>
                                                                               25
           deepen or plug such well. If in the location there is no equipment,
           the procedure mentioned in Clause 21 (numerals 21.1 and 21.2) shall be
           enforced. If at the well site there is adequate equipment to perform
           the operations proposed, the Party that receives the notification of
           the operations that the other Party wishes to carry out, shall have a
           term of forty eight (48) hours following the receipt of the notice, to
           approve or disapprove the operation, if during such term no answer
           whatsoever is received, it is understood that the operation shall be
           done on account and at the risk of the Joint Account. If the work
           proposed is carried out on account and sole risk of one participating
           Party, the well shall be administered pursuant to Clause 21 (numeral
           21.2).
 21.4      If at any time one of the Parties wishes to build new facilities for
           the extraction of liquids from the gaseous Hydrocarbons and for the
           transportation and export of the Hydrocarbons produced, to be called
           additional facilities, such Party shall so advise the other in writing
           giving the following information:
 21.4.1    General description, design, specifications and estimated costs of the
           additional facilities.
 21.4.2    Projected capacity.
 21.4.3    Approximate date of the initiation of the construction and duration of
           the same. Within ninety (90) calendar days from the date of
           notification, the other Party, by written notice, has the right to
           decide if it participates in the additional facilities projected. In
           case in which such Party decides not to participate in the additional
           facilities, or gives no answer to the proposal of the participating
           Party, from hereinafter referred to as the constructing Party, it may
           proceed with the additional installations and order the Operator to
           build, operate and maintain such facilities at the exclusive cost and
           risk of the constructing Party, without prejudice to the normal
           development of the Joint Operations. The constructing Party may
           negotiate with the other Party the use of such facilities for the
           Joint Operation. During the time in which the facilities are operated
           on the constructing Party sole account and risk, the Operator shall
           charge this party all operation and maintenance costs of the
           additional facilities pursuant to the accounting standards generally
           accepted.
                             CHAPTER V - JOINT ACCOUNT
 CLAUSE 22 - HANDLING
 22.1      Without prejudice to any provisions contained herein, the expenses
           covering Exploration Operations shall be on account and risk of THE
           ASSOCIATE.
 22.2      As from the time ECOPETROL accepts the existence of a Commercial Field
           and subject to the provisions in Clause 5 (numeral 5.2) and of Clause
           13 (numerals 13.1 and 13.2), the property of the rights or Interest in
           the Operation of the Contract Area, shall be divided as follows:
           ECOPETROL fifty percent (50%), THE ASSOCIATE fifty percent (50%). From
           the moment of such acceptance, all expenses, payments, investments,
           costs and obligations incurred in and contracted for the development
           of the Joint Operation, in agreement with this contract, shall be
           charged to the Joint Account and the Direct Exploration Costs done by
           THE ASSOCIATE before a Commercial Field is accepted and its
           extensions, pursuant to Clause 9 (numeral 9.9), shall be registered in
           the Joint Account. Except for that established
 <PAGE>
                                                                               26
           in Clauses 14 (numerals 14.3) and 21, all properties acquired or used
           from there on for the fulfillment of the operation activities of the
           Commercial Field shall be paid for and belong to the Parties, in the
           same proportion established in the present clause.
 22.3      Within the first five (5) days of each month, the Parties shall supply
           the Operator, in the bank account of the Joint Account, the quota that
           corresponds them in the Budget of each Commercial Field pursuant to
           the needs and in the currency in which the expenses must be made in,
           meaning, in Colombian pesos or in dollars of the United States of
           America, as per request of the Operator pursuant to the programs and
           Budgets approved by the Executive Committee. When THE ASSOCIATE has
           insufficient Colombian pesos to cover the quota that corresponds it
           from its share in this currency, ECOPETROL shall have the right to
           supply such pesos and to receive a credit for the contributions it
           must make in dollars, liquidated at the market rate certified by the
           Superintendencia Bancaria or by the corresponding authority, of the
           day in which ECOPETROL must make the corresponding contribution, when
           such transaction is allowed by the legal provisions.
 22.4      The Operator shall present a monthly statement to the Parties within
           the ten (10) calendar days following the termination of each month,
           showing the funds advanced, expenses incurred, outstanding liabilities
           and a report on other debits and credits made to Joint Account; this
           report that shall be done as set forth in Annex "B", and in an
           independent Annex, the parameters and calculation of factor R as
           mentioned in Clause 14 (numerals 14.2.3 and 14.2.4). If the payments
           to which Clause 22 (numeral 22.3) refer to are not made within the
           term therein set forth and the Operator decides to cover the same, the
           Debtor Party shall pay the commercial interest in the same currency in
           which the payment has been incurred for the period of time for which
           the payment has been delayed.
 22.5      Should either party, in a timely manner, fails to supply the Joint
           Account with the sums due and payable, as of the due at date such
           Party shall be considered as a Debtor Party, and the other Party, as
           the Prompt Party. If the Prompt Party has made the corresponding share
           to the Debtor Party, in addition to its own, after sixty (60) calendar
           days of delay such Party shall have the right to have the Operator
           issue it the total participation of the Debtor Party, in the Contract
           Area (excluding the percentage that corresponds to the royalty), up to
           an amount of production that shall allow the Prompt Party a net income
           for the sales made equal to the sums not paid by the Debtor Party,
           plus an annual interest equal to the Interest in Arrears after of
           commencement of default.. By "net income" it is understood the
           difference between the sales price of the Hydrocarbons taken by the
           Prompt Party, less cost for transportation, storage, loading and other
           reasonable expenses incurred in by the Prompt Party in the sale of the
           products taken. The right of the Prompt Party may be exercised at any
           time after thirty (30) calendar days from having notified the Debtor
           Party in writing of its intention to take part or all of the
           production shares that correspond to the Debtor Party.
 22.6      Direct and Indirect Expenses.
 22.6.1    All Direct Expenses of the Joint Operation shall be charged to the
           Parties in the same proportion in which the production is distributed
           after the royalties.
 22.6.2    The indirect Expenses shall be charged to the Parties in the same
           proportion established in numeral 22.6.1 of the present Clause for
           Direct Expenses. The amount of these
 <PAGE>
                                                                               27
           expenditures shall be the result of taking the total annual value of
           the investments and direct expenditures (excluding the technical and
           administrative supports) and apply the equation a + m (X-b). In this
           equation "X" is the total value of the annual investments and
           expenditures, and "a", "m" and "b" are constants which values are
           shown in the following chart with relation to the amount of annual
           investments and expenditures:
      AMOUNT OF INVESTMENTS AND EXPENSES                VALUES OF THE CONSTANT
                "X" (US$)                   "a" (US$)   M (frac.)     "b"(US$)
 1.            0       to   25.000.000         0            0.10           0
 2.        25.000.001  to   50.000.000      2.500.000       0.08       25.000.000
 3.        50.000.001  to  100.000.000      4.500.000       0.07       50.000.000
 4.       100.000.001  to  200.000.000      8.000.000       0.06      100.000.000
 5.       200.000.001  to  300.000.000     14.000.000       0.04      200.000.000
 6.       300.000.001  to  400.000.000     18.000.000       0.02      300.000.000
 7.       400.000.001  on                  20.000.000       0.01      400.000.000
           The equation shall be applied only one time per year, in each case
           with the value of the constants that correspond to the total value of
           the annual investments and expenditures.
 22.7      The monthly statements of the account referred to in Clause 22
           (numeral 22.4) may be revised or objected by any of the Parties from
           the time they are received by the Parties up to two (2) years counted
           from the end of the calendar year to which they pertain to, clearly
           specifying the corrected or questioned entries and the reason thereof.
           Any account that has not been corrected nor objected within this
           period, shall be considered as final and correct.
 22.8      The Operator shall keep the accounting records, vouchers and reports
           for the Joint Account in Colombian pesos pursuant with the Colombian
           laws and every debit or credit to the Joint Account shall be made
           pursuant to the accounting procedure established in Annex "B", that is
           part of this contract. In case of disagreement between such accounting
           procedure and that established in this contract, that stipulated in
           this later one shall prevail.
 22.9      The Operator may sell materials or equipment during the first twenty
           (20) years of the Exploitation Period or the first twenty eight (28)
           years of the Exploitation Period, if it concerns a Gas Field, for the
           benefit of the Joint Account, when the value of that sold does not
           exceed five thousand dollars of the United States of America
           (US$5.000) or its equivalent in Colombian pesos. This type of
           operations, per calendar year may not exceed the amount of fifty
           thousand dollars of the United States of America (US$50.000) or its
           equivalent in Colombian currency. The sales in excess of these amounts
           or sales of real property shall be approved by the Executive
           Committee. The sale of such material or equipment shall be done at a
           reasonable commercial price pursuant to the conditions wear of the
           asset.
 <PAGE>
                                                                               28
 22.10     Any machinery, equipment and other assets or personal property
           acquired by the Operator for the execution of this contract, charged
           to the Joint Account, shall be the property of the Parties in the same
           proportion to their Interest in the Operation. However, if one of the
           Parties has decided to terminate its interest in the contract prior to
           the end of the first seventeen (17) years of the Exploitation Period,
           with the exception of that established in Clause 25, such Party is
           obliged to sell its interest in such items to the other Party, at a
           price commercially reasonable or at book value, which ever is lower.
           Should the other Party not wish to purchase such items within the
           ninety (90) calendar days following the formal offer of sale made to
           it, the Party wishing to withdraw shall have the right to yield to a
           third person the Interest that corresponds it in such machinery,
           equipment and items. If THE ASSOCIATE decides to withdraw after
           seventeen (17) years of the Exploitation Period, its rights in the
           Joint Operation shall pass to ECOPETROL free of charge, previous its
           acceptance.
                       CHAPTER VI - DURATION OF THE CONTRACT
 CLAUSE 23 - MAXIMUM DURATION
 This contract shall have a maximum duration of twenty eight (28) years, counted
 as from its Effective Date distributed as follows: up to six (6) years as an
 Exploration Period pursuant to Clause 5 without prejudice of that set forth in
 Clause 5 (numeral 5.4) and in Clause 9 (numeral 9.3); and twenty two (22) years
 as an Exploitation Period as from the date of the termination of the Exploration
 Period. It is understood that in the events contemplated in this contract, in
 which the Period of Exploration is extended, in no case, shall the total term of
 twenty eight (28) years be extended.
 Paragraph 1: The Exploitation period for the Gas Fields that are discovered
 within the Contract Area shall have a maximum duration of thirty (30) years as
 from the date of expiration of the Exploration Period or of the Retention Period
 granted. In any case, the total term of the contract for such Fields may not
 exceed forty (40) years from its Effective Date.
 Paragraph 2: Notwithstanding the afore mentioned, ECOPETROL and THE ASSOCIATE,
 with an anticipation not less than five (5) years to the date of expiration of
 the Exploitation Period of each Field, shall study the conditions to continue
 with its exploitation subsequent to the term to which this Clause refers to. In
 such case in which the Parties agree to continue such exploitation, they shall
 define the terms and conditions within which it shall be performed.
 CLAUSE 24 - TERMINATION
 This contract shall be terminated in any of the cases hereinafter mentioned and
 in which the rights of THE ASSOCIATE mentioned in this contract shall stop, both
 as interested Party, and in its character of Operator, if at the time of the
 expiration the two qualities mentioned concur in THE ASSOCIATE.
 24.1      Due to the expiration of the Exploration Period without THE ASSOCIATE
           having discovered a Commercial Field, except for that provided in
           Clauses 5 (numeral 5.4), 9 (numerals 9.5) and 34.
 <PAGE>
                                                                               29
 24.2      Upon expiration of the term of the duration of the contract as set
           forth in Clause 23.
 24.3      At any time at THE ASSOCIATE' s will, upon fulfillment of its
           obligations as set forth in Clause 5 and of any others entered into
           hereunder, up to the date of its expiration.
 24.4      If THE ASSOCIATE assigns this contract, fully or in part, without
           having fulfilled that set forth in Clause 27.
 24.5      By not fulfilling the obligations acquired by THE ASSOCIATE pursuant
           to this contract.
 24.5.1    ECOPETROL may not end this contract until after sixty (60) calendar
           days of having notified THE ASSOCIATE or its assignees in writing,
           clearly specifying the causes invoked to make such a declaration and
           only if the other Party has not presented the satisfactory
           explanations to ECOPETROL or if THE ASSSOCIATE has not corrected the
           failure in the fulfillment of the contract, without prejudice of the
           right of THE ASSOCIATE to present the legal resources it considers
           convenient.
 24.5.2    If within the term previously mentioned THE ASSOCIATE presents the
           satisfactory explanations to ECOPETROL and the remaining term to
           complete the time of sixty (60) calendar days is insufficient to
           fulfill the pending obligations pursuant to the good oil industry
           practices, the Parties may agree on an additional term to allow such
           fulfillment, without prejudice of the right of ECOPETROL to demand the
           necessary guarantees to support it. If at the end of this term the
           operations agreed on have not been fulfilled, ECOPETROL shall
           terminate the contract.
 24.6      At any time by mutual agreement of the Parties.
 24.7      By the unilateral causes for termination mentioned in Clause 25.
 CLAUSE 25 - CAUSES FOR UNILATERAL TERMINATION
 25.1      ECOPETROL may unilaterally declare this contract terminated, at any
           time before the expiration of the period set forth in Clause 23, in
           the following instances.
 25.1.1    By death or permanent physical disability or judicial interdiction of
           THE ASSOCIATE, if a natural person.
 25.1.2    By initiation of a process of liquidation of THE ASSOCIATE if a
           juridical person.
 25.1.3    By legal injunction of THE ASSOCIATE that seriously affects the
           fulfillment of the contract.
 25.1.4    When THE ASSOCIATE is conformed by several legal and/or natural
           persons, the causes in numerals 25.1.1 and 25.1.2 shall be applied
           when they seriously affect the fulfillment of the contract.
 25.2      In the case of declaration of a unilateral termination, the rights of
           THE ASSOCIATE mentioned in this contract shall end, both as interested
           Party to the Contract, and as
 <PAGE>
                                                                               30
           operator, if at the time of the declaration of a unilateral
           termination the two qualities mentioned concur in THE ASSOCIATE.
 CLAUSE 26 - OBLIGATIONS IN CASE OF TERMINATION
 26.1      Upon termination of the contract pursuant to Clause 24, either in the
           Exploration, Retention or Exploitation periods, THE ASSOCIATE shall
           leave in production any wells that are then producing and restitute
           the facilities, transfer pipelines and other real property of the
           Joint Account (located in the Contract Area), all of which, shall pass
           free of charge to ECOPETROL with the any rights of ways and assets
           obtained to the exclusive benefit of the contract, even though the
           former or the latter be located outside of the Contract Area.
 26.2      If this contract is terminated for any reason after the first
           seventeen (17) years of the Exploitation Period, all Interest of THE
           ASSOCIATE in the machinery, equipment or other assets or facilities
           used or obtained by THE ASSOCIATE or by the Operator for the execution
           of this contract, shall pass to ECOPETROL free of charge.
 26.3      If this contract is terminated before the seventeen (17) years of the
           Exploitation Period, that set forth in Clause 22 (numeral 22.10) shall
           be applied.
 26.4      In case this contract is terminated by a declaration of a unilateral
           termination issued at any time, all the real and personal property
           acquired for the sole benefit of the Joint Account shall pass to
           ECOPETROL free of charge.
 26.5      Upon termination of this contract by any cause and at any time, the
           Parties are obliged to satisfactorily fulfill their legal obligations
           between each other and before Third Parties and those acquired in this
           contract.
                         CHAPTER VII - VARIOUS PROVISIONS
 CLAUSE 27 - RIGHTS OF ASSIGNMENT
 27.1      THE ASSOCIATE shall be entitled to assign or transfer all or part of
           its interests, rights and obligations originated from this contract,
           with the previous written authorization of ECOPETROL, to another
           person, company or group that has the financial capacity, the
           technical competence, the necessary professional abilities and legal
           capacity to act in Colombia.
           For such purpose, THE ASSOCIATE shall submit a written request to
           ECOPETROL, indicating the essential elements of the negotiation, such
           as the name of the possible assignee, information on his legal,
           financial, technical and operational capacities, the cost of the
           rights and obligations to be assigned, scope of the operation, etc.
           Within the sixty (60) working days following the receipt of the
           request, submitted in a complete form, ECOPETROL, shall exercise the
           discretional faculty to study the information supplied by THE
           ASSOCIATE, after which it shall adopt its determination, without being
           obliged to motivate it.
 27.1.1    When the assignments are in favor of companies that control or direct
           THE ASSOCIATE, or of any one of the companies that integrate it or
           their affiliates or subsidiaries, or between
 <PAGE>
                                                                               31
           companies that conform the same economic group, it shall be sufficient
           to previously and timely notify ECOPETROL on the essential elements of
           the negotiation previously mentioned.
 27.1.2    The operations performed under the development of this clause, and
           that pursuant to the Colombian Legal Tax legislation, are taxable,
           shall cause the payment of the corresponding taxes.
           Paragraph: When THE ASSOCIATE is conformed by more than one company
           and one of them wishes to totally or partially assign its interests,
           rights and obligations in the contract pursuant to this clause, it
           must give preference to the other companies that integrate THE
           ASSOCIATE, offering them, before doing so to Private Parties, the
           interests, rights and obligations it wishes to assign, unless the
           companies that conform THE ASSOCIATE have agreed otherwise.
                             CLAUSE 28 - DISAGREEMENTS
 28.1      In the event of any discrepancies or inconsistencies in the
           interpretation of the Clauses of this contract with relation to those
           set forth in Annex "B" called the "Operating Agreement", those
           stipulations of the first shall prevail.
 28.2      The disagreements that arise between the Parties on matters of rights
           related with the interpretation and execution of the contract and that
           cannot be solved in a friendly way, are subject to the knowledge and
           decision of the legal branch of the Colombian public authorities.
 28.3      Any difference as to the facto or technical matters that may arise
           between the parties hereto as a result of the interpretation or
           application of this contract and that cannot be solved in a friendly
           manner, shall be subject to a final decision of experts appointed as
           follows: one by each Party and, the third one, appointed by mutual
           agreement by the principal experts appointed. Should these two fail to
           reach an agreement as to the appointing of the third, the latter shall
           be designated upon request of either Parties by the Board of Directors
           of the Sociedad Colombiana de Ingenieros "SCI" (Colombian Society of
           Engineers), with offices in Bogota, D.C.
 28.4      Any differences of an accounting nature that may arise between the
           Parties hereto by reason of the interpretation and implementation of
           the contract, which cannot be solved in a friendly manner, shall be
           referred for the decision of experts who shall be professional public
           accountants designated as follows: one by each Party and, the third
           appointed by the two principal experts; should these fail to reach an
           agreement and by request of any of the Parties, such third expert
           shall be designated by the Central Board of Accountants of Bogota
           (Junta Central de Contadores de Bogota).
 28.5      Both parties declare that the experts decision shall have all the full
           effect of a settlement between them and in consequence, such decision
           shall be final.
 28.6      In case of disagreement between the Parties on the technical,
           accounting or legal nature of the controversy, it shall be considered
           legal and Clause 28 (numeral 28.2) shall be applied.
 <PAGE>
                                                                               32
                         CLAUSE 29 - LEGAL REPRESENTATION
 Without prejudice to THE ASSOCIATE's legal rights and as a consequence of the
 legal provisions or of the clauses of this contract, ECOPETROL shall represent
 the Parties before the Colombian authorities on any matters concerning the
 exploitation of the Contract Area whenever it is necessary, and shall supply the
 officers and government entities with all the data and reports that may be
 legally required. The Operator shall be obliged to prepare and supply ECOPETROL
 with the corresponding reports. Any expenses incurred in by ECOPETROL to attend
 any matter to which this Clause refers to, shall be charged to the Joint
 Account, and when such expenses exceed five thousand dollars of the United
 States of America (US$5.000) or its equivalent in Colombian currency, the
 previous approval of THE ASSOCIATE is required. The Parties declare, for any
 relation with Third Parties, that neither that established in this Clause nor in
 any other of this contract, shall imply the granting of a general power of
 attorney, moreover that the Parties have constituted a civil or commercial
 association or any other relationship under which, any of the Parties may be
 considered as jointly and severally liable for the acts or omissions of the
 other party or as having authority or mandate that may be binding upon the other
 Party in relation to any obligation. This contract is concerned to the
 activities within the territory of the Republic of Colombia, and even though
 ECOPETROL is a Colombian State-Owned and industrial company, the Parties agree
 that THE ASSOCIATE, given the case, may choose to be excluded from the
 enforcement of all the provisions of Sub-chapter K titled PARTNERS AND
 PARTNERSHIPS of Internal Revenue Code of the United States of America. THE
 ASSOCIATE shall make such election on its behalf and in the appropriate manner.
 CLAUSE 30 - RESPONSIBILITIES
 30.1      The liabilities Contracted hereunder by ECOPETROL and by THE ASSOCIATE
           with relation to Third Parties shall not be joint and, in consequence,
           each Party shall be separately liable for its share in the expenses,
           investments and obligations that may result as a consequence of such
           liabilities.
 30.2      Environmental Management. During the performance of all of the
           activities provided for in the contract, THE ASSOCIATE or the
           Operator, shall on time comply with the provisions of the National
           Code on Natural Renewal Resources and Environmental Protection, issued
           by the Colombian Government, as well as with all other relevant legal
           regulations. Also, motivate among their contractors, suppliers,
           intermediaries, and/or workers working in benefit of this contract,
           the conservation of a healthy environment, taking the necessary
           precautions to protect the environment, human life and property of
           others and prevent the contamination of the Contract Area. From the
           beginning of this contract, THE ASSOCIATE shall elaborate a general
           diagnostic on the environmental and social reality of the zones where
           the Exploration Operations shall be executed and shall establish the
           communication channels with the authorities and communities of the
           area.
           THE ASSOCIATE is obliged to execute a permanent preventive program to
           guarantee the preservation and restoration of the natural resources
           within the zones where the operations of Exploration, exploitation and
           transportation set forth in this contract are carried out.
           Such plans and programs must be made known by THE ASSOCIATE to the
           national and regional communities and entities related to this issue.
           Also, specific contingency programs must be established to face those
           emergencies that may occur and to carry out the
 <PAGE>
                                                                               33
           necessary remedial actions. For such effect, THE ASSOCIATE must
           coordinate such plans and actions with the competent authorities.
           The respective programs and Budgets must be prepared by THE ASSOCIATE
           pursuant to the corresponding Clauses of this contract.
           All costs caused shall be assumed by THE ASSOCIATE during the
           Exploration Period and in the exploitation under the modality of sole
           risk, and by both Parties with charge to the Joint Account in the
           Exploitation period.
 CLAUSE 31 - TAXES, CHARGES AND OTHERS
 The taxes and charges accrued after the opening of the Joint Account and before
 the Parties receive their production share, chargeable to the exploitation of
 Hydrocarbons, shall be charged to the Joint Account. Income, patrimony and
 supplementary or presumptive taxes, shall be to the sole account of each of the
 Parties as applicable to each of them.
 CLAUSE 32 - PERSONNEL
 32.1      When THE ASSOCIATE is the Operator, the assignment of the Manager of
           the Operator shall be previously consulted with ECOPETROL.
 32.2      Pursuant to the terms of this contract and subject to the regulations
           established, the Operator in his condition as the sole and true
           employer, shall have the autonomy to assign the personnel required for
           the operations hereunder, being able to set the salaries, duties,
           ranks and conditions. The Operator shall adequately and diligently
           train the Colombian personnel required to replace the foreign
           personnel that the Operator considers necessary for the performance of
           the operations of this contract. In any case, the Operator must
           fulfill all the legal provisions that show the proportion of national
           and foreign employees and workmen.
 32.3      Technological Transfer - THE ASSOCIATE is obliged to pay for or
           perform at its cost the training programs for the professionals of
           ECOPETROL in areas related to the development of the contract.
           For the fulfillment of this obligation in the Exploration Period, the
           training may also be in the areas of geology, geophysics and related
           areas, evaluation of Reservoirs and characterization of reservoirs,
           drilling and production. The supervised training shall be done
           throughout the entire Exploration Period of six (6) years and during
           its extensions, by integrating the professionals that are assigned by
           ECOPETROL, to the work group organized by THE ASSOCIATE for the
           Contract Area or for other activities handled by THE ASSOCIATE.
           To be able to choose to resign as set forth in Clause 5 of this
           contract, THE ASSOCIATE must have previously fulfilled the training
           programs herein mentioned.
           During the Exploitation Period, the scope, duration, place,
           participants, training conditions and other aspects, shall be
           established by the Executive Committee of the Company.
 <PAGE>
                                                                               34
           All costs for guided training, with the exception of those of work
           caused in favor of the professionals that receive it, shall be assumed
           by THE ASSOCIATE in the Exploration Period and by both parties with
           charge to the Joint Account in the Exploitation Period.
           PARAGRAPH: To fulfill all of the Technological Transference
           obligations pursuant to that herein mentioned, during the first three
           (3) years of the Exploration Period and for each year, THE ASSOCIATE
           is committed to carry out programs of guided training and technical
           exchanges for professionals of ECOPETROL in the areas of joint
           interest up to a value of forty thousand dollars (US$40.000) per year.
           The subject and type of program shall be previously agreed to between
           ECOPETROL and THE ASSOCIATE. In the event that the Exploration Period
           is extended, the guided training shall consist of similar programs to
           that herein considered.
 CLAUSE 33 - INSURANCES
 THE ASSOCIATE or the Operator shall obtain all the insurances required by the
 Colombian laws. Also, it shall require that each contractor performing any type
 of work during the development of this contract obtain all the insurances
 considered necessary, that must be maintained in force. Also, the Operator shall
 take all other insurances that the Executive Committee considers necessary.
 At the expiration of this contract, at any moment during the exploitation period
 or by expiration of a term set forth in clause 23, the Operator and/or THE
 ASSOCIATE shall constitute an insurance policy that guarantees the payment of
 salaries, benefits and indemnifications and other working credits for eventual
 legal sentences derived from claims of the workers contracted by the Operator in
 his condition as a sole and true employer of the same and during the time of
 operation of the Commercial Field. The life of the policy shall not be less than
 three (3) years as of the date of the termination of the Association Contract
 and the sum insured shall be decided by the Executive Committee, subject to that
 ordered in the labor regulations that apply to the respective labor contracts.
 CLAUSE 34 - FORCE MAJEURE OR ACT OF GOD
 The obligations to which this contract refer to shall be suspended for the time
 in which any of the Parties is unable to fulfill them in whole or in part, due
 to unforeseeable events that constitute a force majeure or Act of God, such as
 strikes, lockouts, wars, earth quakes, floods or other catastrophes, laws or
 government regulations or decrees that hinder the provision of essential
 material and, in general, any non financial motive that really impedes the work,
 even when not previously mentioned, but that affects the Parties and that is out
 of their control. Should either Party be unable to fulfill its obligations with
 this contract due to force majeure or Act of God, it must immediately notify the
 other Party, for its consideration, specifying the causes of its impediment. In
 no case can the events of force majeure or Act of God extend or prolong the
 total period of exploration, retention and exploitation beyond a maximum
 duration of the contract pursuant to that set forth in Clause 23, but any
 impediment of force majeure during the period of six (6) years of exploration
 set forth in Clause 5, which duration is more than sixty (60) consecutive days,
 shall extend this period of six (6) years for the same period of the duration of
 the impediment.
 <PAGE>
                                                                               35
 CLAUSE 35 - APPLICATION OF THE COLOMBIAN LAWS
 The Parties set the city of Bogota, D.C., Republic of Colombia for any purposes
 hereunder. This contract is governed ruled in all of its parts by the Colombian
 laws and THE ASSOCIATE abides by the jurisdiction of the Colombian Courts and
 waives any diplomatic claim in respect to its rights and obligations hereunder,
 except in the case of denial of justice. Denial of justice shall not be deemed
 to exist when THE ASSOCIATE in its condition as a Party or as Operator has had
 access to all the resources and ways of action that, pursuant to the Colombian
 laws, may be used before a jurisdictional branch of the public power.
 CLAUSE 36 - NOTIFICATIONS
 Notices or communications between the Parties hereto in relation to this
 contract, shall require for their validity mentioned or the pertinent clauses
 and shall be sent to the representatives or delegates assigned by the Parties to
 the following addresses: ECOPETROL: Carrera 13 No. 36.24, Bogota, D.C.,
 Colombia. To THE ASSOCIATE: Calle 114 No. 9-01 Bogota, D.C., Colombia. The
 change of address and of representative shall be notified to the other Party in
 advance.
 CLAUSE 37 - VALUATION OF THE HYDROCARBONS
 The payments or Reimbursements set forth in Clauses 9 (numerals 9.2 and 9.4) and
 22 (numeral 22.5), shall be made in dollars of the United States of America, or
 in Hydrocarbons based on the price in effect and with the limitations
 established or that may be established by the Colombian legislation for the sale
 of that portion of the Hydrocarbons payable in dollars, originated from the
 Contract Area, and to be refined within the national territory.
 CLAUSE 38 - PRICES FOR HYDROCARBONS
 38.1      The Hydrocarbons to which THE ASSOCIATE is entitled to in the
           development of this contract, to be refined or used in internal
           supply, shall be paid when situated at the refinery where they shall
           be processed or at the station where they are received as agreed to by
           the Parties, pursuant to the government rules and regulations in force
           or those that substitute them.
 38.2      The differences that arise from the application of this Clause shall
           be solved through the systems established in this contract.
 CLAUSE 39 - DELEGATION AND ADMINISTRATION
 The PRESIDENT of EMPRESA COLOMBIANA DE PETROLEOS - ECOPETROL appoints the
 administration of this contract in the Vice-President of Exploration and
 Production, pursuant to the rules and Reglementary provisions of ECOPETROL, with
 faculties to execute all the matters concerning the development of this
 Contract. The Vice-President of Exploration and Production is authorized to
 perform this assignment through the Assistant Vice-Presidents of Exploration and
 Production.
 <PAGE>
                                                                               36
 CLAUSE 40 - LANGUAGE
 For all effects and acts related to this contract, the official language is
 Spanish.
 CLAUSE 41 - VALIDITY
 To be valid, this contract requires the approval of the Ministry of Mines and
 Energy.
 In witness whereof, it is signed in Bogota, D.C., before witnesses, on the
 twentieth (20) day of the month of December of the year two thousand (2001).
                          EMPRESA COLOMBIANA DE PETROLEOS
                                     ECOPETROL
                                (Signed) illegible
                              ALBERTO CALDERON ZULETA
                                     President
                            HARKEN DE COLOMBIA LIMITED
                                (Signed) illegible
                          GABRIEL GUSTAVO CANO VELASQUEZ
                          Principal Legal Representative
                                     WITNESSES
           (Signed) Illegible                      (Signed) Illegible
           VICTOR EDUARDO PEREZ                      ALBERTO TOVAR
 <PAGE>
                                                                               37
                                   CAJARO SECTOR
                                      ANNEX A
 <PAGE>
                                                                               38
                                      ANNEX A
                                   CONTRACT AREA
              ANNEX TO THE ASSOCIATION CONTRACT OF THE CAJARO SECTOR
 The area of the polygon formed by the vertices mentioned hereinafter is of
 thirty four thousand one hundred ninety five (34.195) hectares with seven
 thousand fifty eight (7.058) square meters and is located within the municipal
 jurisdiction of Mani in the department of Casanare. The cartographic information
 was taken from the Political Map of Colombia, digital file of the I.G.A.C., at a
 scale of 1:1'500.000.
 The Contract Area is described as follows and, as it appears on the map enclosed
 as Annex "A", that is part of this contract, as well as the corresponding
 charts: The Geodesic Vertex "RECREO- 912" of the Agustin Codazzi Geographical
 Institute has been taken as the point of reference, which flat GAUSS coordinates
 with origin Bogota are: N-1'051.829,47 meters, E-1'158.055,62 meters, that
 correspond to the geographic coordinates Latitude 05(0) 03'58"0,207 to the North
 of the Equator, Longitude 72(0) 39'20"0,698 West of Greenwich. From this vertex
 it bears S 50(0) 43'3"0,552 E for a distance of 70.494,393 meters until reaching
 point "A" start off point of boundaries which coordinates are N-1007.196,48
 meters, E-1'212.620,77 meters. From this point it bears S 67(0) 33'25"0.116 E
 for a distance of 3.709,75 meters until reaching point "B", which coordinates
 are N- 1'005.780,23 meters, E-1'216.049,54 meters. The line "A-B" is contiguous
 in all of its extension with line "C-B" of the Alcaravan Association Contract
 operated by Harken. From this point it bears S 58(0) 57'42"0.358 E for a
 distance of 18.968, 27 meters until reaching point "C" which coordinates are
 N-996.000,00 meters, E 1'232.302,00 meters. From this point it bears S 54(0)
 42'41"0.066 W for a distance of 22.725,46 meters until reaching point "D" which
 coordinates are N-982.871,61 meters, E- 1'213.752,28 meters. The point "D" is
 contiguous with point "D" of the Vuelta Laraga Association Contract operated by
 the Emerald company. From this point it bears N 23(0) 38'28"0.601 W for a
 distance of 9.395,40 meters until reaching point "E" which coordinates are
 N-991.478,49 meters, E- 1'209.984,64 meters. From this point it bears N 51(0)
 1'59"0.565 W for a distance of 9.036,48 meters until reaching point "F", which
 coordinates are N- 997.161,26 meters, E- 1'202.958,68 meters. From this point it
 bears N 43(0) 54'53"0.153 E for a distance of 13.930,60 meters until reaching
 point "A" start off point and closure of the boundaries. Lines "D-E", "E-F" and
 "F-A" are contiguous in all their extension with lines "O-N", "N-M" and "M-L" of
 the Bicudo Association Contract operated by the Braspetro company.
 <PAGE>
                                                                               39
                                                                         ANNEX -A
                          EMPRESA COLOMBIANA DE PETROLEOS
                         Calculation of Area, courses and
                 Distances as of Gauss Coordinates. Origin Bogota
                   Data and Results Chart for the CAJARO Sector
           Municipal Jurisdiction of Mani in the Department of Casanare
 POINT Coord. N. Coord. E. Distance Dif.N. Dif. East Courses
 <PAGE>
                                                                               40
                        ANNEX B TO THE OPERATIONS AGREEMENT
                         ANNEX TO THE ASSOCIATION CONTRACT
                              FOR THE "CAJARO" SECTOR
 Entered into by the Empresa Colombiana de Petroleos - ECOPETROL and HARKEN DE
 COLOMBIA LIMITED, with effective date February eighteenth (18th) year two
 thousand two (2002), which hereinafter shall be known as The Contract.
                            PART 1 - TECHNICAL ASPECTS
                             Section One - Exploration
 The geological and geophysical information that THE ASSOCIATE is to provide to
 ECOPETROL, shall be provided following the international norms accepted by the
 industry, compatible with the norms used by ECOPETROL (included in ECOPETROL's
 information provision manual) in order to allow for regional assessments of the
 sedimentary basins. As a supplement of what is provided for in Clause 6 (number
 6.2) in The Contract, THE ASSOCIATE or the Operator shall deliver to ECOPETROL,
 as it becomes available, the following information with respect to the
 exploratory activities that are undertaken by THE ASSOCIATE.
 1.1       The geological, geophysical, magnetometric, gravimetric information
           from remote sensors, electrical methods and, in general, from any
           Exploration Work performed by THE ASSOCIATE in the development of The
           Contract shall be submitted in magnetic media, in a reproducible
           original and one copy, with its respective support information,
           including the maps related with the acquisition and interpretation of
           the acquisition, processing and interpretation reports for the data
           acquired.
 1.2       Processed seismic sections for each line, obtained in two scales,
           together with an interpretation report to contain: information used,
           background, seismic programs, geological information and geophysical,
           geological and economic considerations that back up the conclusions
           and technical recommendations.
 1.3       Two (2) sets of magnetic tapes corresponding to the seismic lines, one
           with the de- multiplexed information and the other with the stacked
           information, with their support information and processing report. For
           the case of vibrators, a copy of the field tape is to be delivered in
           lieu of the de- multiplexed tape.
 1.4       One seismic shot-point map, in reproducible sepia and copy, with the
           information of coordinates and elevations. This information shall also
           be delivered on magnetic tapes.
 1.5       Magnetic, gravimetric profiles and residual maps in reproducible
           originals, copies and magnetic tapes, with all of the support
           information generated.
 1.6       Report on the seismic, gravimetric and magnetometric interpretation,
           together with all of the sections, profiles and maps interpreted,
           submitted set forth in the norms that ECOPETROL has established for
           this information.
 1.7       Geological, structural, isopach, isolithic, facies, seismic, etc. maps
           for The Contract area, in reproducible sepias and copies, with the
           scales established by ECOPETROL for each basin.
 1.8       Before starting to drill the well: Intention to Drill (Form 4- CR of
           the Ministry of Mines and Energy), drilling program, well location
           map, isochronic or structural map of the prospective
 <PAGE>
                                                                               41
           area and the geological drilling prognosis, duly approved by the
           Ministry of Mines and Energy. In the event of Exploratory Wells, the
           following shall also be submitted in three scenarios: the calculation
           for the Reservoirs in the prospective area to be drilled and the
           forecast of investments and production. The location of the
           Exploratory Wells shall be referenced to the seismic maps that served
           as the basis for the definition of the prospect. For each of the
           Exploratory Wells that is drilled in The Contract area, a geodesic
           precision point shall be materialized, duly accepted by the Agustin
           Codazzi Geographical Institute - "IGAC," obtained by satellite and
           with its respective azimuth line.
 1.9       Daily drilling and geology reports: These reports shall be delivered
           to ECOPETROL, preferably by telefax, and shall contain the basic
           information on the well, the drilling conditions, the properties of
           the drilling fluid, the manifestations of Hydrocarbons that are being
           obtained, the geological description of the formations penetrated, the
           daily and cumulative cost and the program to be carried out. The
           ASSOCIATE or the Operator shall advise ECOPETROL with sufficient
           advance notice on the performance of electrical logs, cores and
           testing, so that the latter can send a representative to attend and
           witness all of the operations.
 1.10      Copy of the reports sent to the Ministry of Mines and Energy (Form 5-
           CR) every two weeks.
 1.11      Final Geological Report: This report is compulsory for any well that
           is drilled in the country, whether it be exploratory, stratigraphic,
           or development, and shall be submitted in Spanish, by a registered
           geologist, latest ninety (90) days after the date of termination or
           abandonment of the well, and shall include the following information
           by chapters:
 1.11.1    Summary of all activities performed during the drilling operations
 1.11.2    Location of the well and maps at a 1:250,000 scale.
 1.11.3    Stratigraphy: shall include the stratigraphic column, determination of
           environments and age for each of the formations drilled.
 1.11.4    Biostatigraphy: The dispersion charts, analyses performed and possible
           correlations are to be submitted.
 1.11.5    Geochemistry: All of the analyses performed shall be included, both
           for the ditch samples and for each of the cores recovered.
 1.11.6    Electrical logs: All of the calculations performed for the
           determination of RW, SW shall be included. The analysis of log
           velocity shall be included in this chapter.
 1.11.7    Formation testing: All of the results obtained for each of the tests
           performed shall be included, as well as the results of the analyses
           performed in the laboratories for water and Hydrocarbons.
 1.11.8    The Final Geological Report shall contain the following Annexs:
           Annex A: Description of the ditch samples at every ten (10) feet.
           Annex B: Detailed description of the cores and side wall samples that
           may have been recovered.
           Annex C: All of the laboratory analyses that are performed on the
           cores and side wall samples.
 <PAGE>
                                                                               42
           Annex D: Composite graphic log, in reproducible sepia and copy at a
           1:500 scale. The symbols that are used by the American Association of
           Petroleum Geologists (AAPG) for these cases shall be used for the
           various lithologies included in the composite graphic log.
           Annex E: Final report issued by the company that performed the
           "logging" for the well, including the "Grapholog" log.
 1.12      Reproducible sepias and copies of each and every log run in the well,
           including the velocity log, in 1:200 and 1:500 scales. In addition,
           the magnetic tapes in LIS format for each of the logs shall be
           delivered, together with the computer tabulations in the formats
           established by ECOPETROL for these cases.
 1.13      Report on the formation and/ or production tests performed, including
           the analysis of bottom hole pressure (both open well and closed).
 1.14      Two sets of ditch samples shall be delivered to ECOPETROL, one
           unwashed every thirty (30) feet and a dry one every ten (10) feet,
           with the detailed lithological description.
 1.15      Coring report, whenever performed, including the detailed description
           for it, as well as on all of the analyses that are carried out. With
           this report, THE ASSOCIATE is to deliver photographs to ECOPETROL, as
           well as 50% of the core.
 1.16      A report on all of the materials used during drilling.
 1.17      Biostratigraphic analyses with their dispersion chart: These analyses
           shall be performed for Exploratory Wells, since the sedimentation
           environments and the age of each of the formations drilled are defined
           with this information. This type of analysis can also be performed on
           the various recovered cores.
 1.18      Geochemical analyses performed on the ditch, side wall and core
           samples.
 1.19      Official completion, plugging or abandonment report for the well (Form
           6- CR or 10A- CR) and, in general, any other report related with the
           termination of the well (further work, multiple termination).
 1.20      Final Well Report. Shall include all of the engineering information
           and a summary of the Final Geological Report. It shall be submitted in
           the Spanish language, latest ninety (90) days after the date of
           termination or abandonment of the well, with the approval of a duly
           registered petroleum engineer.
 1.21      Copy of the Annual Technical Report (Geology and Geophysics and of the
           Engineering Report), with their respective support, submitted to the
           Ministry of Mines and Energy, set forth in the existing legal
           provisions.
 1.22      Any other engineering or geology study that may be performed.
 CLAUSE 2 - RESTITUTED OF AREAS
 2.1       The areas that THE ASSOCIATE shall restitute to ECOPETROL, set forth
           in Clause 8 of The Contract shall be, inasmuch as possible, regular
           lots with a polygon shape, attempting to facilitate the demarcation of
           borders, without prejudice of the areas in the existing Fields. For
           such purpose, an imaginary grid or grille shall be superimposed upon
           the initially Contract area, divided into ten rows and columns in a
           north- south direction, the limits of which shall be given by the
           maximum and minimum border north and east coordinates,
 <PAGE>
                                                                               43
           which shall define the base cells for the areas to be restituted
           herein. Every time an area is restituted, the imaginary grid or grille
           shall be adjusted, based on the new coordinates for the Contract Area.
 2.2       THE ASSOCIATE shall determine the areas that it shall restituted to
           ECOPETROL, based on the imaginary grid or grille mentioned in the
           above point. For such purpose, it shall carry out the restitution of
           up to two lots made up by one or more cells that are contiguous and
           adjacent on their sides, and trying to conserve a sole polygon, unless
           THE ASSOCIATE demonstrates that this is not possible or convenient,
           for which purpose it shall require ECOPETROL's approval.
 CLAUSE 3 - EXTENSIVE PRODUCTION TESTS
 The following is the established procedure for performing Extensive Production
 Testing for Exploratory Wells and for the handling of Hydrocarbons from such
 tests, prior acceptance or not of the existence of a Commercial Field by
 ECOPETROL, set forth in Clause 9 of The Contract:
 3.1       THE ASSOCIATE is entitled to perform Extensive Production Tests for
           the Exploratory Wells that turn out to be producers, with the purpose
           of assessing in the best manner, the Reservoir or Reservoirs
           discovered and prepare the Development Program for the possible Field.
           Before initiating the Extensive Production Tests THE ASSOCIATE shall
           obtain ECOPETROL's approval and subsequently, permission from the
           Ministry of Mines and Energy. Such tests shall be performed with
           temporary production facilities and shall not require more than ninety
           (90) calendar days, unless THE ASSOCIATE proves the contrary and
           obtains timely approval from ECOPETROL and from the Ministry of Mines
           and Energy, respectively.
 3.2       THE ASSOCIATE, on its own account and risk, shall, set forth in
           international oil industry recommended rules and practices, carry out
           the Extensive Production Tests accepted by ECOPETROL and authorized by
           the Ministry of Mines and Energy, set forth in the operations program.
           In order to obtain such approvals, THE ASSOCIATE shall prepare and
           submit to ECOPETROL the operations program for the Extensive
           Production Testing, which shall contain, among others, the following
           aspects:
 3.2.1     Information of the completion of the Exploratory Well and of the
           Reservoirs to be tested.
 3.2.2     Specific objectives for the Extensive Production Tests.
 3.2.3     Information to be compiled on the Reservoirs and fluids, periodicity
           for sampling, analyses and data on the possible Field, such as type,
           quality and properties of rocks and fluids, pressures, volumes of "in
           situ" and recoverable Hydrocarbons, maximum economic Hydrocarbons
           production rate, production mechanism, etc.
 3.2.4     Information on the subsurface equipment and temporary surface
           facilities to be used to handle and decant the volumes of fluids
           obtained and other equipment required to ensure the safety of the
           operations, including the location diagram for the temporary surface
           facilities on site.
 3.2.5     Detailed chronogram on the main activities to be performed in order to
           achieve the specific objectives referred to in number 3.2.2. mentioned
           above.
 3.2.6     Budget for the main activities to be carried out and the estimated
           disbursement schedule.
 <PAGE>
                                                                               44
 3.2.7     Destination of the Hydrocarbons and other fluids to be recovered from
           the Extensive Production Testing.
 3.2.8     Evacuation and marketing scheme for the Hydrocarbons from the
           Extensive Production Tests (including the volume the corresponds to
           royalties) and reference price proposal subject to be agreed upon with
           ECOPETROL for the valuation of such Hydrocarbons.
 3.2.9     Draft contract and proposals (at least three) for the transport of the
           Hydrocarbons to be produced corresponding to the royalties set forth
           in Clause 13 of The Contract, from the Exploratory Well to the
           delivery point of such Hydrocarbons to ECOPETROL.
 3.2.10    Any other information that THE ASSOCIATE may consider necessary.
 3.3       ECOPETROL may request clarification or suggest adjustments to the
           operations program submitted by THE ASSOCIATE for the execution of the
           Extensive Production Tests. When this occurs, THE ASSOCIATE shall
           submit the explanations to ECOPETROL and, if required, shall bear in
           mind the comments proposed by ECOPETROL, it being understood that, in
           any case, the responsibility and the risk for any operation that is
           included in the operations program for the Extensive Production Tests
           shall be the responsibility of THE ASSOCIATE. Once the operations
           program is accepted by ECOPETROL and the appropriate agreements have
           been reached, it shall be submitted to the Ministry of Mines and
           Energy by THE ASSOCIATE in order to obtain the corresponding
           permission.
 3.4       THE ASSOCIATE shall be responsible for one hundred percent (100%) of
           the disbursements incurred during the Extensive Production Tests,
           including the costs of transporting the volumes of hydrocarbons
           corresponding to the royalties, if this were the case, from the
           Exploratory Well to the delivery point that the Parties agree to, set
           forth in the transportation proposal accepted by ECOPETROL. The costs
           incurred on account of Extensive Production Testing for each
           Exploratory Well shall be charged as an increased value for the
           respective Exploratory Well and shall be considered as Direct
           Exploration Costs (without including administrative or technical
           support from Head Office, nor from the central headquarters of the
           Company) for purposes of their recovery or Reimbursement, set forth in
           the origin of their disbursement.
 3.5       The volumes produced during the Extensive Production Tests shall be
           those recovered from the respective Exploration Well during the
           maximum time period for testing approved by the Ministry of Mines and
           Energy in the corresponding permit, discounting any volume of the
           Hydrocarbons that may be used as consumption in the testing
           operations. The remaining production, once the percentage
           corresponding to royalties has been discounted, which shall be paid
           directly by ECOPETROL, shall be taken by THE ASSOCIATE, and the income
           stemming from the valuation of such Hydrocarbons at the reference
           price agreed to by the Parties, shall be deducted from the Direct
           Exploration Costs for the respective Exploratory Well, up to a maximum
           of fifty percent (50%) of such costs, for purposes of their recovery
           or Reimbursement in the following order: i) Direct Exploration Costs
           in the Extensive Production Tests; ii) Direct Exploration Costs in the
           drilling and completion of the respective Exploratory Well; and iii)
           Direct Exploration Costs incurred in Exploration Work undertaken
           before the drilling of the respective Exploratory Well. Once fifty
           percent (50%) of the Direct Exploration Costs has been recovered, the
           production from the Extensive Production Tests shall be distributed
           between the parties in a proportion of fifty percent (50%) for
           ECOPETROL and fifty percent (50%) for THE ASSOCIATE.
 <PAGE>
                                                                               45
 3.6       Prior consent by ECOPETROL, THE ASSOCIATE may carry out the sale of
           the portion of production of Hydrocarbons from the Extensive
           Production Tests corresponding to the royalties and to ECOPETROL. In
           this case, the Parties shall previously enter into the corresponding
           agreement.
 3.7       THE ASSOCIATE shall keep at the disposal of ECOPETROL the daily logs
           of the production and consumption measurements of Hydrocarbons and
           fluids, the disbursements incurred and the valuation of the produced
           Hydrocarbons at the agreed to reference price, with their respective
           support documentation and the balance in the recovery of Direct
           Exploration Costs in the development of the Extensive Production Tests
           for each Exploratory Well. In addition to the periodic reports on the
           progress of the Extensive production Tests for each Exploratory Well,
           THE ASSOCIATE shall, within the first ten (10) days each month, submit
           to ECOPETROL, a report wherein the development of the operations
           program for the Extensive Production Tests, the results obtained in
           the fulfillment of the specific objectives for the tests and the
           status of income and disbursements are reflected, taking as the basis
           the cumulative values for the accounting closure for the month prior
           to that for which the report is submitted. The information that THE
           ASSOCIATE submits in the periodic reports shall be subject to audit by
           ECOPETROL under the terms provided for in Clause 22 of this agreement.
                            Section Two - Exploitation
 CLAUSE 4 - COMMERCIAL FIELD
 4.1       THE ASSOCIATE, once it has obtained sufficient information related to
           the development of the Field, shall carry out the necessary studies to
           define the criteria on the petrophysical parameters, improved
           demarcation of the productive area, calculation of Reservoirs and
           commercial feasibility of the Field. Such studies shall be carried out
           by THE ASSOCIATE at its own expense, using the technical methods
           available in country or abroad; when the circumstances require it, the
           appropriate reviews shall be performed.
 4.2       For new facilities, expansions or modifications, the basic production
           designs and detail engineering shall be submitted to the consideration
           of the Technical Subcommittee.
 4.3       The engineering for the production facilities shall be Contract with
           national companies, unless, in the decision of the Technical
           Subcommittee, their technological complexity requires the involvement
           of a foreign company, preferably in a consortium with a national
           company.
 4.4       The final mechanical completion of the wells passing to the Joint
           Account's property must agree upon by the Technical Subcommittee. The
           Reimbursement for such completion for the Exploratory Wells shall be
           made as set forth in Clause 9 (numbers 9.2.1 through 9.2.3) herein.
 4.5       With respect to the dry Exploratory Wells, THE ASSOCIATE shall abandon
           them as set forth in the actual legal and environmental provisions.
 CLAUSE 5 - SOLE RISK
 <PAGE>
                                                                               46
 5.1       The Reimbursement corresponds to two hundred percent (200%) of the
           total cost of the work executed on the account and risk of THE
           ASSOCIATE in the exploitation of the corresponding Field and of up to
           fifty percent (50%) of the Direct Exploration Costs made by THE
           ASSOCIATE on its own account and risk within the Contract Area before
           the date on which ECOPETROL makes a statement with respect to the
           commerciality of the Field, which have not been previously charged to
           a different Field. ECOPETROL shall carry out an audit to determine the
           amount of the reimbursable investments.
 5.2       In the same manner as set forth in Clause 11 numeral 11.1 of The
           Contract, THE ASSOCIATE shall submit to ECOPETROL the proposal on the
           projects, programs and Budget, set forth in the Field Development
           Program, for the first time, within sixty (60) calendar days following
           the date of the notification to ECOPETROL by THE ASSOCIATE with
           respect to its intention to exploit the Field under the sole risk
           method and subsequently, latest on the fifteenth (15th) of November of
           each year. ECOPETROL may, with the corresponding justification,
           request clarification or suggest adjustments to the programs, projects
           and Budget submitted by THE ASSOCIATE. When this were to occur, THE
           ASSOCIATE shall submit the explanations to ECOPETROL and, if this were
           the case, shall bear in mind the comments proposed by ECOPETROL in the
           preparation of the revised Development Plan, being understood that in
           all cases, the responsibility and the risk for any operation shall
           fall upon THE ASSOCIATE. The Development Plan for the Fields that are
           exploited under the sole risk method shall be reviewed annually and
           shall be consistent with international oil industry standards for the
           technical, efficient and economic exploitation of each field.
 5.3       During the exploitation of a Field under the sole risk method, THE
           ASSOCIATE shall deliver to ECOPETROL, within the first ten (10) days
           of each quarter, a report listing all of the technical, economic,
           legal, administrative and accounting information for the previous
           quarter, such as the entering into of contracts, well completion, flow
           lines, production facilities, measuring systems, storage capacity,
           wells in production, restriction orifices, production reports,
           economic studies, etc. It is understood that the various Clauses in
           The Contract and the clarification in this document are fully
           applicable in the case of Clause 21 of The Contract, Operations for
           the Risk of one of the Parties, for purposes of timely information,
           the technical control of Reservoirs and other administrative aspects.
 5.4       Within the first three (3) months of each year, THE ASSOCIATE shall
           contract an external auditor, accepted by ECOPETROL, to review the
           total costs of the work executed for the account and risk of THE
           ASSOCIATE for the exploitation of the respective field and the Direct
           Exploration Costs. The cost of the audit shall be part of the expenses
           that THE ASSOCIATE shall recover. THE ASSOCIATE shall deliver to
           ECOPETROL, immediately after having received them, the reports issued
           by the external auditor and shall maintain at its disposal all of the
           documentation on the costs in which THE ASSOCIATE has incurred in the
           exploitation of the respective field.
 CLAUSE 6 - INSPECTION OF THE OPERATIONS
 For the inspection and audit of the activities that are carried out in the
 Contract Area, ECOPETROL may send its representatives. During their stay in the
 area, THE ASSOCIATE or the Operator shall provide lodging and other conditions
 designated by ECOPETROL, equal to those provided for its engineers.
 <PAGE>
                                                                               47
 CLAUSE 7 - PRODUCTION
 7.1       The Operator shall also transmit to the Parties any information of
           improvements in production techniques that it may develop during the
           Exploitation Period.
 7.2       For the control and prevention of Hydrocarbon losses and damage to the
           environment, the Operator and the Parties shall apply the appropriate
           measures, with the generally accepted methods used by the oil industry
           in order to avoid Hydrocarbon losses or spills in any way during the
           drilling, production, transport and storage operations.
 7.3       The Operator shall maintain a daily control of consumption of
           Hydrocarbons for the operation and shall submit a monthly report of
           these to the Parties, attaching the forms that the Ministry of Mines
           and Energy has for this purpose.
 CLAUSE 8 - DISTRIBUTION AND AVAILABILITY OF HYDROCARBONS
 8.1       As per Clause 14 (number 14.1) of The Contract, the Operator shall
           carry out the measurement, sampling and quality control of the
           Hydrocarbons produced and maintain the measuring equipment or
           instruments calibrated, as set forth in the standards and methods
           accepted by the oil industry (ASTM, AGA and API) and the legal and
           regulatory provisions in force, performing the appropriate analyses
           and performing the pertinent corrections for the settlement of the net
           volumes of Hydrocarbons received and delivered under standard
           conditions. In order to preserve the integrity, reliability and safety
           of the facilities and the equipment or instruments for control, the
           Operator shall adopt all of the necessary actions and shall maintain,
           for purposes of review by the Parties, the records of periodic
           calibration of such equipment or instruments and of the daily
           measurements of production and consumption of Hydrocarbons and fluids.
           For the case of Extensive Production Testing and for Fields exploited
           under the sole risk, it shall be THE ASSOCIATE's responsibility to
           abide by the obligations assigned to the Operator in this number. The
           volumes of Hydrocarbons that the Operator accepts for its
           transportation shall be determined with the measuring equipment that
           the Operator shall have installed for this purpose at the receiving
           stations or delivery points.
 8.2       If at any time the Parties were to ascertain that there has been an
           error in the calculation of the R Factor set forth in Clause 14
           (numbers 14.2.3 and 14.2.4) herein, and that on account of this error
           it turns out that a different R Factor than the one applied is to be
           applied, or that it should have been applied at a different time than
           the one it was applied at, the corresponding correction shall then be
           made, with effect for the year in which the error was incurred in,
           adjusting the percent participation that corresponds to each Party as
           of that year. To perform the respective corrections with regard to the
           distribution of production, a similar procedure to the one described
           in Clause 14 (number 14.7) of The Contract shall be followed.
 CLAUSE 9 - SUPPLY OF HYDROCARBONS FOR EXPORT
 For purposes of Clause 14 of The Contract, in order to proceed with the export
 of Hydrocarbons, THE ASSOCIATE's priority shall be the domestic requirements of
 the country, before performing any export of Hydrocarbons, set forth in the
 legal provisions that may be in force regarding this matter.
 <PAGE>
                                                                               48
                    PART II - ACCOUNTING AND FINANCIAL ASPECTS
                   Section One - Programs, Projects and Budgets
 CLAUSE 10 - EXPLORATION BUDGET AND PROGRAMS
 10.1      With respect to the Budget set forth in Clause 7 herein, THE ASSOCIATE
           shall differentiate and detail it, according to the type of
           Exploration Work and to the indication of the currency in which the
           disbursement is forecast to be made. With respect to the reports every
           six months, these shall be submitted within the first ten (10)
           calendar days of the months of January and July. The January report
           shall refer fully to the previous year and the July report to the
           first half of the current calendar year.
 CLAUSE 11 - EXPLOITATION PROGRAMS AND BUDGETS
 11.1      For purposes of Clause 11 herein, the Operator shall submit the
           proposal for projects, programs and annual Budget, set forth in the
           Development Plan for each Commercial Field, with a detail short- term
           and medium- term outlook. The short- term Budget shall be submitted
           annually and by quarters, in order to facilitate its execution and for
           the preparation of the corresponding treasury flows.
 11.2      The Operator shall submit to ECOPETROL the organization chart for the
           operation of each Commercial Field, which shall be agreed to at
           Subcommittee level and approved by the Executive Committee.
 CLAUSE 12 - BUDGET PREPARATION AND PRESENTATION
 The following norms and procedures constitute the guidelines for the
 preparation, presentation and control of the Budgets during the exploitation of
 each Commercial Field that may be discovered in the development of The Contract.
 The Budget shall be divided into three (3) parts, namely:
 12.1      Income Budget
 12.2      Expenditures Budget
 12.3      Other provisions
 CLAUSE 13 - INCOME BUDGET
 This Budget, is in turn, broken down into two (2) sections: Current income
 Budget and Capital contributions.
 13.1      Current Income:
           All funds which regularly accrue in the Joint Account and which the
           Operator can forecast. Such income includes the following items, when
           applicable:
 13.1.1    Product sales:
           Income from the sale of Hydrocarbons that the Operator may perform on
           behalf of the Parties, to one of the Parties, or to Third Parties (it
           shall be understood that these sales are different from those made by
           each of the Parties of the production to which they are entitled to).
 <PAGE>
                                                                               49
 13.1.2    Services Furnished:
           All services that the Operator furnishes to one of the Parties or to a
           Third Party, in accordance with the rates established by the
           Sub-Committees and approved by the Executive Committee.
 13.1.3    Sales of assets or materials:
           Sales of equipment or materials which the Operator makes to the
           Parties or to third parties as provided in Clause 20 (numeral 20.2) of
           this Agreement.
 13.1.4    Other income:
           All funds received by the Operator on account on behalf of the Joint
           Account, for items such as the yield on temporary financial
           investments and other income that may be forecast by the Operator.
 13.2      Capital Contributions:
           All funds received by the Operator on account of advances made by each
           of the Parties according to their share in The Contract. This income
           is given the name of advances or advance payments (cash calls) and
           shall be handled as set forth in the procedures in Clause 15 (number
           15.5) in this Agreement.
 CLAUSE 14 - EXPENSE BUDGET
 As a prior step to its preparation, the Executive Committee, through the
 respective Subcommittees, shall set the policies and general parameters to be
 borne in mind when elaborating the Budget for the respective Commercial Field.
 The expense or appropriations Budget is made by the Operational Expenses Budget
 and by the Investment Budget, each of which shall be prepared in the currency of
 origin for its disbursement in pesos and in dollars of the United States of
 America, and shall be consolidated in dollars.
 14.1      Operations expense Budget.
           The operations expense budget shall be prepared by the Operator as set
           forth in the norms and policies established by the Executive Committee
           as per Clause 19 (number 19.3.8) of The Contract, and taking as the
           base parameters and economic indicators, that the respective
           Subcommittee has defined as being the most representative for the
           budget execution term.
 14.1.1.   Preparation Procedure
           The Operator shall submit the Operating Expenses Budget, identifying
           the requirements of the Joint Operation, and shall detail the expense
           items set forth in the classification indicated in Clause 14 (number
           14.1.2) of this Agreement.
           The cost factors for the assessment of the various activities that it
           plans to carry out during the year to which the Budget refers to,
           shall correspond to the true figures known at the time of preparation
           or, to the best information available. In all cases, the operating
           expense Budget shall be calculated bearing in mind the costs that are
           required by the entities that,
 <PAGE>
                                                                               50
           directly, render services to the Joint Account and, as such, are to be
           assumed one hundred percent (100%) by the Joint Account and charged
           back to the Parties in the proportion that Clause 22 (number 22.6.1)
           of The Contract refers to. The Indirect Expenses that are to be
           assumed by the Joint Account shall be charged to the Parties and shall
           be determined as set forth in Clause 22 (number 22.6.2) of The
           Contract.
 14.1.2    Classification for the operating expenditure Budget
           For all presentation purposes, the operating expenditure Budget shall
           be broken down into programs, groups and expenditure concept. The
           expenditure programs within the Budget represent homogeneous
           activities necessary for the development of the Joint Operation,
           including those programs related with the investment projects. The
           expenditure groupings in numerical and continuous order within each
           program and project represent the object of the expense, shall be duly
           supported and explained, and shall be expressed in expenditure
           concepts. Following is a listing of the groups and the main
           expenditure concepts to be used:
 14.1.2.1  Personnel expenses - organization chart
           Salaries
           Social Benefits
           Parafiscal contributions
 14.1.2.2  Material and operation supplies
           Repair and maintenance materials
 14.1.2.3  Contracted Services
           Technical services for the operation and Field maintenance
           Services given by the Operator
           Other Services
 14.1.2.4  General Expenditures
           Equipment and office rental
           Shared expenses.
           Insurances.
           Public Utilities.
           Community relations
           Other general expenses.
 14.1.2.5  Environmental Management
           Materials
           Contracted services
           Well abandonment
           Area restoration
           Other expenses
 14.1.2.6  Added tax value (IVA)
 <PAGE>
                                                                               51
 14.1.2.7  Indirect expenses
 14.1.3    Calculation base.
           Calculation for the operating expenses Budget shall be based on the
           following:
           The salary and social benefits Budget shall be calculated as set forth
           in the organization charts approved by the Executive Committee and
           their estimate shall be made as set forth in Clause 18 (number 18.1.1)
           herein. The calculation of salaries, social benefits and other special
           extra-legal bonuses originated by national and foreign personnel shall
           be presented separately, according to the origin of the disbursement,
           to be presented to the Subcommittees and the Executive Committee.
           The estimate of the cost of materials and supplies shall be made based
           on actual prices or updated quotations and, in general, with the best
           available information.
           Importation expenses shall be based on the FOB price calculations for
           the materials and/or equipment to be imported, and in their
           preparation the following factors shall be considered: freight,
           insurance, taxes for the use of Colombian ports, import duties and all
           other import expenses.
           The value of maintenance and operational services contracted shall be
           estimated on contracts formalized or to be formalized that the Joint
           Operation may have at the time the Budget is prepared.
           Indirect expenses chargeable to he Joint Account for services that are
           or may be provided by the Operator shall be calculated as set forth in
           Clause 22 (number 22.6.2) of The Contract).
           The purpose for the Budget for environmental expenses is to
           appropriate the annual funds that are required to fulfill
           environmental norms.
           General expenses shall be calculated taking into account the specific
           need of the Joint Operation in the normal course of its work. Shared
           expenses are those expenditures that are to be assumed by the Joint
           Account as a result of the use of facilities and/or services that are
           shared between Fields in the same Contract or with other areas. The
           Budget and the charges made to the Joint Account for general expenses
           shall be recommended by the Subcommittees and approved by the
           Executive Committee. Community Assistance will be budgeted on both the
           request of the interested parties and according to the policies that
           for such effect are established by the Executive Committee. In special
           duly-justified circumstances, the Operator may deal with requests
           according to its procedures, after first notifying each of the Parties
           on such matters
 14.1.4    Budget Execution
           Execution of the operations expense Budget shall be made as follows:
 14.1.4.1  All services, purchases or contracts that are charged to the Joint
           Account on account of operations expenses shall be budgeted and fully
           justified.
 14.1.5    Budget execution control
 <PAGE>
                                                                               52
           The Operator is responsible for controlling the expense budget
           execution and must see that expenses are properly managed.
           Within the first ten (10) calendar days following the end of the
           respective quarter, the Operator shall prepare and submit to the
           Parties a report explaining the results obtained in the Budget
           execution, which shall contain:
 14.1.5.1  Expenses accrued to date, itemized as per expense categories set forth
           Clause 14 (number 14.1.2) in this Agreement.
 14.1.5.2  Special comments on items which deviate significantly from budget
           average or quarterly estimate.
 14.1.5.3  Estimated expenses forecast for disbursements per quarter or for the
           rest of the year.
 14.1.5.4  Justification for possible budget additions, adjustments or transfers
           that the Operator may deem necessary or that are proposed by one of
           the Parties.
 14.2      Investment Budget
           Constitutes the basic planning, execution and control tool for each of
           the investment programs and projects that the Joint Operation foresees
           it shall carry out, and acts as means to estimate the required funds
           in the execution of the various programs that are approved by the
           Executive Committee.
 14.2.1    The investment Budget is composed of items allotted for the following
           items:
 14.2.1.1  Purchase of durable goods, materials and services required for the
           execution of the different projects approved by the Executive
           Committee.
 14.2.1.2  Purchase of major maintenance equipment and tools destined for the
           Joint Operation shops, in order to ensure the normal development of
           the operations.
 14.2.1.3  Construction and/ or expansion of buildings that the operation may
           require, including the facilities destined for workers in the
           Commercial Field's organization chart.
 14.2.2    Classification of the Investment Budget
           For all presentation purposes, the Investment Budget shall be grouped
           into programs and projects. Programs, in numerical order within each
           Budget, represent a set of projects to be undertaken which, on account
           of their technical, operational and administrative characteristics,
           merit being controlled in a connected manner and which the Joint
           Operation shall execute through the Operator. Projects, in a numerical
           and continuous order within each program, constitute the set of
           activities that are common to a specific work or job and shall be duly
           supported and explained. Following are the main programs and projects
           to be used:
 14.2.2.1  Development Wells
           Locations
           Drilling
           Completion
           Surface equipment, artificial lifting, recompletion and services that
           are capitalizable to the wells.
 14.2.2.2  Surface facilities
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                                                                               53
           Collection system and transfer lines
           Separation and treatment system
           Storage system
           DISPOSAL OF WATER AND CONTAMINANTS
           Pressure maintenance and/ or improved recovery system
           Pump Stations
           Hydrocarbon transport and transfer system
           Other support systems
 14.2.2.3  Civil Work
           Roads
           Bridges
           Constructions (camp, workshops, warehouses and offices)
 14.2.2.4  Other assets
           Automotive equipment
           Firefighting equipment
           Communications equipment
           Office equipment
           Electromechanical maintenance equipment
           Major tools
           Cleaning or workover equipment
 14.2.2.5  Special programs
           Environmental management
           Reservoir studies
           Simulation studies
           Pressure, interference, etc. tests
           Others
 14.2.2.6  Warehouses
           For projects.
           For maintenance materials.
 <PAGE>
                                                                               54
 14.2.2.7  Each one of the above projects can be broken down into sub-projects as
           needed, using a uniform identification. Final presentation thereof
           shall be made on a project by project basis, according to the
           classification given above and using forms two (2) and four (4)
           established by ECOPETROL for such purpose which may be adapted by
           previous agreement between the Parties, through the corresponding
           Subcommittee. In order to achieve increased clarity in the preparation
           and structuring of the investment Budget, the following considerations
           are to taken into account:
 14.2.2.7.1 Maintenance investments
           All investments made in equipment, materials and construction for the
           purpose of keeping facilities in good operating condition as well as
           their original capacity and performance limits.
 14.2.2.7.2 Enlargement Investment
           The investments are to be classified as such if their objective is to
           increase the facility capacity, increase the authorized provision of
           automotive equipment, office equipment, etc.
 14.2.2.7.3 Special investments
           These include all of those investments which, on account of their
           amount, their importance for the industrial activities or their impact
           on a social or ecological level, merit being classified as special.
 14.2.3    Preparation and presentation of the Budget
           Each and every one of the projects within the various programs that
           make up the Investment Budget shall be fully justified and analyzed
           before being included in the general Budget. In this sense, the
           Operator shall prepare an investment draft which shall contain the
           following general information:
           a)   Analysis of needs
           b)   Project justification
           c)   General project description
           d)   Estimated amount of the investment
           e)   Execution chronogram
           f)   Critical path for the project
           g)   Economic evaluation
           The draft with the aforementioned information, plus any other
           information that may be considered necessary for its assessment that
           the Operator may submit, shall be studied jointly by the respective
           Subcommittees, which shall recommend or object to the viability of the
           project, as set forth in the policies drawn up by the Executive
           Committee.
           Once such Subcommittees recommend that a specific project be
           undertaken, the project shall then be included in the Budget to be
           approved by the Executive Committee for the respective Commercial
           Field.
 <PAGE>
                                                                               55
           All of the general information that is submitted to justify each
           project will be compiled in a Technical-Financial Annex, which shall
           serve as support when presenting the Budget for each Commercial Field
           for the approval of the Executive Committee.
 14.3      Budget Consolidation.
           Once the Joint Operation's requirements have been defined, the
           Operator will consolidate the Operations Expense and Investment Budget
           for each of the Commercial fields, as set forth in classification in
           Clause 14 of this Agreement (numerals 14.1.2 and 14.2.2 respectively)
           and shall present it to the Executive Committee for final approval.
           The Operation Expense Budget and the investment Budget, will be
           submitted in four columns that will contain the accrual origin in
           United States of America dollars, accrual origin in pesos, a
           consolidated statement in dollars and one in pesos, using the forecast
           of the exchange rate for the respective year for this purpose. In
           addition, the Operator shall prepare, for information purposes, a
           disbursement chronogram that indicates the cash requirements in the
           short term, itemized by quarter and by currency origin, at the level
           of expense group, program and investment project.
 14.4      Budget Execution
           In all cases, the Operator is authorized to make all of the operations
           and investment expenses that the Joint Operation requires, set forth
           in the approved Budget and subject to the procedures in this
           Agreement, and those that the Executive Committee may establish. The
           execution of the budget shall be performed by the Operator through its
           various departments and set forth in the previously established
           execution schedules.
           The appropriations assigned to each project shall be identified with a
           previously defined code, which shall be used on all documents that
           originate in carrying out its budgetary execution.
 14.5      Budget Control.
           The Operator shall be responsible for carrying out each of the
           investment programs and projects and shall be accountable for the
           execution of these within the conditions under which they were
           approved.
           Similarly, it shall be responsible for the verification that the
           corresponding steps for the performance of the projects are taken
           adequately and on a timely basis. In the event that any problem is
           encountered that prevents the normal development of the projects, it
           shall immediately report it in writing to each of the Parties, in
           order to seek the solution to the difficulty that has been
           encountered. The Operator, as the responsible party for the
           Development Plan, the programs, projects and Budget, shall prepare the
           quarterly reports regarding the budget and technical advance of these,
           which it shall send to each of the Parties for their study and
           subsequent approval by the Executive Committee.
           The quarterly report that is to be prepared and presented by the
           Operator within the ten (10) days following the end of each quarter,
           shall contain the following information:
           a)   Period covered by the report.
           b)   Project code and description.
           c)   Total project budget.
           d)   Financial advances from its start to final date. Investments per
                current-year, accumulated to date.
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                                                                               56
           e)   Technical progress of the work.
           f)   Quarterly projection of work to be carried up to year-end, for
                information purposes.
 CLAUSE 15 - OTHER PROVISIONS
 15.1      Budget Additions
           If, during the execution of the Budget, it were necessary to add
           supplementary items above and beyond the appropriations approved by
           the Executive Committee, the Operator shall request the corresponding
           modifications from the Parties in an extraordinary manner and their
           ratification shall be made in the next ordinary meeting of the
           Executive Committee.
           On a periodic basis, requests for budget transfers or additions for
           expenses and investments may be submitted, studied and approved, every
           time the Executive Committee meets on an ordinary basis. However, the
           Executive Committee may meet in an extraordinary manner to deal with
           budgetary issues any time a special situation may so merit.
           Every time that a budget addition is requested, the Operator shall
           initiate, with due lead time, the corresponding procedures, submitting
           the requests to the respective Subcommittee for its study and
           subsequent recommendation to the Executive Committee. In any event,
           the requests for budget additions shall be fully justified, explaining
           the reasons that gave rise to the variation in the appropriated items,
           with their respective technical and financial Annex, as specified in
           Clause 14 (number 14.2.3) in this Agreement.
 15.2      Budget transfers
           Those appropriations that are carried over from one year to another as
           a result of those projects that could not be concluded during the term
           for which they were budgeted for reasons such as the lack of
           availability of equipment, importation procedures, bad weather, among
           others, shall be considered to be budget transfers.
           When a project is not totally completed, the value of the budget shall
           become part of the Budget for the immediately following year and shall
           be subjected to approval by the Executive Committee. The presentation
           of these projects within the Budget shall be singled out and
           specifically identified and shall be considered in the preparation of
           the disbursement schedule that Clause 15 (number 15.4) in this
           Agreement refers to. In addition, budget transfers shall give rise to
           an Annex wherein the cause for the budget transfer shall be explained,
           as well as the way in which it is to be executed during the following
           term.
 15.3      Approvals
           The Executive Committee shall be entity entrusted with approving the
           programs, projects and the Budget recommended by the Subcommittees,
           and with authorizing the Operator to purchase or contract, for the
           account of the Joint Account, all of those goods and services that are
           required by Joint Operation.
 15.4      Disbursement Schedule
           Together with the overall Budget, the Executive Committee shall
           approve the Budget by quarters submitted by the Operator and
           recommended by the Subcommittees for the immediately following year,
           and which shall constitute the basis on which the monthly cash calls
           shall be calculated.
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 15.5      Cash Calls
           The requests for advances of funds or cash calls shall be made by the
           Operator to each of the Parties, based on the obligations entered into
           by the Joint Operation for the month immediately following the one of
           the request, referring to the quarterly Budget approved by the latest
           Executive Committee and the forecast cash flows. The management of the
           advances or cash calls that this Clause refers to shall be made
           through a bank account that the Operator shall establish for such
           purpose, for the exclusive use by the Joint Operation. In the
           preparation of the requests for advances or cash calls, the following
           requirements are to be followed:
 15.5.1    Preparation
           Based on the approved Budget and the obligations entered into on
           behalf of the Joint Operation for the following month, the Operator
           shall prepare the requests for advances, bearing in mind the following
           conditions:
 15.5.1.1  The request shall be made by the Operator separately for each of the
           Commercial Fields being exploited in the Contract Area, identifying
           operations and investment expenses, in pesos and in United States of
           America dollars, depending on the origin in which the disbursement is
           forecast to be made.
 15.5.1.2  The request shall be by programs and projects, in the case of
           investments, and by group and expense item in the case of expenses, in
           the same manner in which they are listed in the Budget approved by the
           Executive Committee.
 15.5.1.3  For each of the projects and expense items listed in the request for
           advance funds to be considered, they must be included in the Budget;
           otherwise, they shall be deducted from the total amount requested.
 15.5.1.4  The projects and expense groups shall necessarily have a sufficient
           Budget.
 15.5.2    Presentation
           The request for funds (cash call) shall be made by the Operator within
           the first twenty (20) days of the immediately preceding month to the
           month in which the contributions are to be made. If the Operator were
           to have to make extraordinary disbursements, that are not provided for
           at the time that the monthly advance cash call is made, it shall
           request special advances in writing from the Parties, covering their
           respective share in such disbursements.
           Every request for an advance or cash calls shall be submitted for
           processing in the form previously agreed to by the Parties in the
           respective Subcommittee and shall show the actual and estimated
           charges for investments and expenses and shall comprise the following
           documents:
 15.5.2.1  Letter of Request
 15.5.2.2. Request format, wherein the financial status for each of the programs,
           projects and expense items is shown on the date on which the request
           is made.
 15.5.2.3. General comments of a technical nature in which the destination of the
           requested funds is identified, within the main projects or expense
           items.
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                        Section Two - Accounting Procedure
 CLAUSE 16 - ACCOUNTING PROCEDURE
 In each half- yearly report that Clause 10 (number 10.1) in this Agreement
 refers to, THE ASSOCIATE shall submit to ECOPETROL the direct Explorations Costs
 for the period of the report that could be subject to reimbursement in agreement
 with Clause 9 of The Contract, with the indication of the currency in which the
 disbursement was made and a consolidated statement in United States of America
 dollars. In addition, in this same report, THE ASSOCIATE shall submit the
 preliminary cumulative value that is to be included as variable "A" for the
 calculation of the R Factor that Clause 14 (numbers 14.2.3 and 14.2.4) in The
 Contract refers to, clearly showing the parameters used for the calculation, It
 is understood that the Direct Exploration Costs shall only be definitive once
 they have been audited and accepted by ECOPETROL.
 During exploitation of each Commercial Field, the credits and charges incurred
 in by the Operator in development of the Joint Operation, shall be charged to
 the Joint Account set forth in the provisions of Clause 22 of The Contract. The
 Joint Account shall be divided into three main items, as stated below, for each
 Commercial Field discovered in performance of The Contract, and the consolidated
 statement, when there is more than one Commercial Field in the Contract Area:
 16.1      General Joint Account (clarification, charges and entries).
           This account shall reflect all of the movements, as is expressed later
           on, and shall be fully distributed on a monthly basis between the
           Parties, in a share of fifty percent (50%) for ECOPETROL and fifty
           percent (50%) for THE ASSOCIATE with respect to the investments, and
           in the proportion that is set out in Clause 22 (numbers 22.6.1 and
           22.6.2) in The Contract for Direct Expenses and Indirect Expenses.
           That is to say, it shall serve as the basis for monthly billing, set
           forth in the provisions of this procedure, ending every month with a
           balance of zero (0).
           All of the accounting operations related with this account shall be
           booked by the Operator in Colombian pesos, set forth in the laws of
           the Republic of Colombia, but the Operator may, in turn, keep ledgers
           wherein it shows the disbursements it may incur in any currency other
           than Colombian pesos.
 16.2      Joint operations current account.
           This account shall record the cash calls received from the Parties and
           the charges or credits corresponding to the invoicing of these and, at
           all times, shall show a balance in favor or against each of the
           Parties, as appropriate. This account shall be divided into two sub-
           accounts, set forth in the monetary origin of the transaction, namely:
           Colombian pesos and United States of America dollars.
 16.3      Joint property records.
           Through the Joint Account, the Operator shall keep a record of all of
           the assets acquired that are subject to inventory, indicating in
           detail the kind of asset, the date of purchase and its original cost.
           The accounts mentioned in Clause 16 (numbers 16.1, 16.2 and 16.3) of
           this Agreement shall constitute part of the Operator's official
           accounting records, but without mixing them with accounting records
           other than those of the Joint Account. The three aforementioned
           records shall be subject to Clause 22 of this Agreement.
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                                                                               59
 16.4      The Operator shall send to ECOPETROL on a monthly basis, together with
           the information cited in Clause 17 (number 17.2.2) of this Agreement,
           in an independent Annex, the parameters and the calculation of the R
           Factor, set forth in the provisions of Clause 14 (number 14.2.3 and
           14.2.4) of the Contract. The Operator shall keep in its files and at
           the disposal of the Parties, all of the support documentation for the
           charges made to the variables that are included in the calculation of
           the R Factor for each Commercial Field.
 CLAUSE 17 - ADVANCES, INVOICES AND ADJUSTMENTS
 17.1      Advances.
           Despite the fact that the Operator shall pay and clear, initially, all
           of the costs and expenses incurred set forth in The Contract, charging
           each Party with its percentage share, it is agreed that, to finance
           such share, each Party, at the Operator's request, shall advance to
           the latter, from the moment of acceptance by the Parties of the
           existence of a Commercial Field and, latest within the first five (5)
           days of every month, the proportion of the disbursements for the
           account of each and that were estimated for the operations of the
           given month. These advances shall be made in United States of America
           dollars and in Colombian pesos, set forth in the requirements
           established in the approved Budget by quarter and in the forecast cash
           flow for each Commercial Field and in the requests for advances (cash
           calls) prepared by the Operator, set forth in Clause 15.5 in this
           Agreement.
 17.2      Invoices.
 17.2.1    The Operator shall prepare an initial invoice for ECOPETROL after the
           acceptance of the existence of each Commercial Field, in the amount of
           fifty percent (50%) of the Direct Exploration Costs incurred in before
           the date of ECOPETROL's statement regarding the commerciality of each
           new Commercial Field discovered, that is audited and accepted by
           ECOPETROL set forth in Clause 22 of this Annex and that has not
           previously been charged to another Field. In the Direct Exploration
           Costs for the Exploratory Wells, all of the direct costs incurred in
           drilling, termination and testing shall be included for the case of
           Exploratory Wells that are producers, and the cost of drilling and
           abandonment of the Exploratory Wells that are dry. Such invoice shall
           also include fifty percent (50%) of the costs of additional work that
           Clause 9 (number 9.3) in The Contract refers to, if applicable. For
           the monthly update of the values that the paragraph in Clause 9
           (number 9.2.2) in The Contract refers to, one twelfth (1/12th) of the
           value resulting from averaging the percent annual variation available
           for the last two (2) years in the consumer price index for
           industrialized countries shall be used, taken from the "International
           Financial Statistics" of the International Monetary Fund (page S63 or
           its replacement) or, if not available, the publication that may be
           agreed to by the Parties. This invoice shall include a summary of the
           costs, expressing separately the currency in which the investments and
           the expenses were made, that is to say, in Colombian pesos or in
           United States of America dollars.
 17.2.2    Set forth in Clause 22 (number 22.2) of The Contract, the Operator
           shall charge the Parties, within the ten (10) days following the last
           day of each month, their proportional share of the investments and
           operational expenses during that month. In the invoices, the details
           that may be available in the Operator's accounting procedures shall be
           noted, including a detailed summary of accounts, expressing separately
           the investments and operational expenses originating in pesos and
           those originating in United States of America dollars.
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                                                                               60
 17.2.3    Investments and expenses during the Retention Period.
           The costs and expenses made by THE ASSOCIATE during the Retention
           Period to establish the commercial viability of a Gas Field shall be
           assumed by THE ASSOCIATE in their entirety.
 17.3      Adjustments
           The invoices shall be adjusted between the Operator and the Parties
           after deducting the advances in United States of America dollars and
           in Colombian pesos.
           When the advances made by either of the Parties differ from their
           share in the actual costs determined for each period, the difference
           in pesos and/ or in dollars shall be adjusted in the invoices for the
           following month.
 17.4      Acceptance of the invoices.
           The payment of the invoices shall not affect the right of the Parties
           to protest or inquire about the accuracy of these, set forth in the
           terms of Clause 22 (number 22.7) of The Contract.
 CLAUSE 18 - CHARGES
 Subject to the limitations that are set forth below, the Operator shall charge
 the Joint Account and invoice each Party, set forth in the percentages
 established in Clause 16 (number 16.1) of this Agreement, for the following
 expenses:
 18.1      Labor.
 18.1.1    National and foreign employees
 18.1.1.1  The salaries of the Operator's employees or workers that are working
           directly for the benefit of the Joint Operation, including the payment
           for overtime, nighttime surcharge, payment of Sundays and holidays and
           their respective compensatory rest periods and, in general, all
           payments that constitute salary.
 18.1.1.2  Social benefits, compensation, insurance, subsidies, bonuses and, in
           general, any benefit that is not salary and that is awarded to the
           workers and/ or their relatives or dependents, whether it is granted
           individually or collectively, or whether it is granted to them by
           virtue of the labor contract, the law, arbitration conventions or
           sentences, with the exception of housing plans, with respect to which
           a special agreement shall be required. Among the aforementioned, one
           can cite, among others, the following: severance pay, vacation,
           retirement and disability pensions, benefits to retirees and their
           relatives, benefits and aid caused on account of professional or non-
           professional illnesses and accidents, service bonuses, life insurance,
           compensation or indemnity on account of contract cancellation, labor
           union benefits, all types of bonuses, subsidies and aid, for savings,
           health, education and, in general, for social security. In addition,
           the contributions to the Colombian Family Welfare Institute (ICBF),
           National Vocational Training Service (SENA), Social Security Institute
           (ISS) and other similar ones that may be established.
 18.1.1.3  All expenses incurred for the benefit of the Joint Operation with
           respect to the maintenance and operation of the camp, its offices and
           service facilities at the site. Among these, the following expenses
           are also included, not in a restrictive manner but rather as a
           listing, as indicated below, whether the services are rendered for
           free or for payment, or
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                                                                               61
           whether they be for the workers, their dependents or relatives, of
           that these be provided in a voluntary or compulsory manner.
           Such services include the following:
           18.1.1.3.1    Medical, pharmaceutical, surgical and hospital services.
           18.1.1.3.2    Camp and full services thereof, including its repairs
                         and sanitation.
           18.1.1.3.3.   Training and educational expenses.
           18.1.1.3.4    Workers recreation.
           18.1.1.3.5    Maintenance of schools for the workers, their children
                         and dependent relatives.
           18.1.1.3.6    Safety, social work and camp surveillance.
 18.1.1.4  It is understood that the expenses and services outlined in the
           aforementioned Clause 18 (numbers 18.1.1.1, 18.1.1.2 and 18.1.1.3)
           shall be for the account of the Joint Account when, by provisions of
           law, labor agreements and/ or arbitration sentences or voluntarily,
           they are applicable in a direct or by extension to contractors,
           subcontractors, intermediaries and/ or their workers who are working
           for the benefit of the operation.
 18.1.1.5  With respect to retirement pensions and disability compensation, the
           Executive Committee shall proceed set forth in the provisions of the
           Social Security and Pension System established by Law 100 issued in
           1993 and other norms that regulate it or substitute it.
 18.2      Materials, equipment and supplies
           The materials and supplies that are necessary to undertake the
           operations shall be charged to the Joint Account. The materials and
           supplies shall be purchased for warehouse inventories for the projects
           or for the maintenance materials warehouse when it is convenient for
           the operation and shall be credited to it, at cost in the books, as
           they are withdrawn from the warehouse to be used. The capital
           equipment units shall be charged directly to the Joint Account. The
           book cost is determined as follows:
 18.2.1    Book cost
           It is understood that book cost means the last average price of the
           inventory in the warehouse, based on the cost obtained in the import
           liquidation sheets, or the local cost, as follows:
 18.2.1.1  For imported materials, equipment and supplies, the book cost shall
           include the net price on the manufacturer or vendor's invoices, the
           cost of purchases, freight and delivery charges between the supply
           point and the loading point, freight to the entry port, insurance,
           import duties or any other tax, handling from the vessel to the
           customs warehouse and transport to the site of operations.
 18.2.1.2  For materials, equipment and supplies purchased locally, the book cost
           shall include the seller's net invoice, plus sales taxes, procurement
           expenses, transport, insurance and other similar costs paid to Private
           Parties, from the purchase location to the site of operations.
 18.2.1.3  the materials shall be charged to the Joint Account set forth in the
           monetary purchase origin, so that it can similarly be charged to each
           Party.
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                                                                               62
 18.2.2    Return of materials to Joint Operation's warehouses, as the case may
           be.
           The materials, equipment and supplies that are returned to the
           warehouses of the Joint Operation shall be valued as follows:
 18.2.2.1  New materials, at book cost.
 18.2.2.2  Second- hand materials, in good condition and that can render service,
           as well as equipment that can subsequently be used without repairs,
           can be reincorporated by the Operator to the corresponding warehouse
           at one hundred percent (100%) of their cost on the books, crediting
           the respective project in the Joint Account.
 18.2.2.3  Second- hand equipment and materials which, when repaired, can be
           used, can be reincorporated by the Operator to the corresponding
           warehouse at one hundred percent (100%) of their cost on the books.
           These materials, upon being used again, shall be charged at the new
           book value.
 18.2.3    Sales by the Parties. The materials, equipment and supplies sold by
           the Parties to the Joint Operations shall be valued at the replacement
           price agreed to by the Parties. The corresponding transport costs
           shall be for the account of the Joint Operation. In the cases of sales
           by the Joint Operation to one of the Parties, these shall be valued at
           the replacement price agreed to by the Parties, and the transport
           costs shall be for the account of the purchasing Party.
 18.2.4    Local transport of materials
 18.2.4.1  For materials shipped through an external transporter, at cost, set
           forth in the invoice issued by the transportation company.
 18.2.4.2  For materials sent in transportation units owned by the Parties, at
           the fees calculated to cover the actual costs, pursuant to the
           procedure established in Clauses 18 (number 18.4) and 23 (number
           23.1.1) in this Agreement.
 18.2.5    Materials for projects that have been cancelled, postponed or changed.
           When there is an accumulation of inventory in the warehouse on account
           of the change, deferral or cancellation of projects approved by the
           Parties, the cost of such materials shall be charged to the warehouse
           account. These materials may be sold to Private Parties set forth in
           the provisions of Clause 20 (number 20.2.1) in this Agreement and what
           is obtained shall be credited to the Joint Account. Surplus materials
           from projects, purchased with direct charge. Once the project has been
           finalized, these should be reincorporated to the warehouse and
           credited to the corresponding projects. The Operator shall advise the
           Parties of this operation at the ordinary meetings of the Financial
           Subcommittee when this were to occur.
 18.3      Travel expenses
           All travel expenses incurred on behalf of the Joint Operation for
           Colombian or foreign personnel, such as transport, hotels, food, etc.
 18.4      Service units and facilities
           The value of the service rendered for equipment and facilities that
           are owned by any of the Parties shall be charged to the Joint Account
           at reasonable rates, as provided for in Clause 23 of this Agreement.
           The rates that are established shall be applied until such time as
           they are modified by mutual agreement.
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                                                                               63
 18.5      Service
           Services rendered by Private Parties, including contractors, to the
           Joint Operation, at their actual cost. Similarly, technical services,
           such as laboratory analyses and special studies, require the
           recommendation of the Technical Subcommittee and approval by the
           Executive Committee.
 18.6      Repairs
           Expenses for repairs made to the equipment or elements of either of
           the Parties, destined for use by the Joint Operation, unless these
           costs have already been charged through leasing or in another manner.
 18.7      Litigation
           Expenses to the Joint Operation regarding the threat of effective
           lawsuits (including the investigation and collection of evidence),
           lifting encumbrances, sentences, legal claims and procedures for
           claims, compensation for accidents, settlement for death and funeral
           expenses, provided that these charges have not been recognized by an
           insurance company or covered by the proportional surcharges mentioned
           in Clause 18 (number 18.1.1) in this Agreement. When legal services
           are provided in these matters by permanent or external counsel, whose
           total or partial compensation is included in indirect costs, no
           additional charges shall be made for their services, but rather, these
           shall be charged to Direct Expenses incurred in such procedures.
 18.8      Damages and losses of Joint Operation property and equipment.
           All costs and expenses necessary to replaced or repair damage or
           losses caused by fire, flood, storm, theft, accident or any other
           similar event. The Operator shall notify the Parties in writing
           regarding the damages or losses occurred, as soon as possible.
 18.9      Taxes and rentals
           The value of all taxes paid or accrued in carrying out the Joint
           Operation shall be charged to the Joint Account, in keeping with the
           existing legal provisions.
           The value of leases, right of way and indemnity for improvements, the
           occupation of land, etc. shall also be charged to the Joint Account.
 18.10     Insurance
 18.10.1   Premiums paid for insurance taken out for the benefit of the
           operations that The Contract refers to, together with all of the
           expenses and indemnities accrued and paid, an all losses, claims and
           other expenses that have not been covered by the insurance companies,
           including the legal services mentioned in Clause 18 (number 18.7) in
           this Agreement, shall be charged to the Joint Account.
 18.10.2   When no insurance exists, the actual costs incurred, mentioned above,
           and paid for by the Operator, shall also be charged to the Joint
           Account.
 CLAUSE 19 - CREDITS
 19.1      Incomes
           The Operator shall credit the Joint Account for incomes resulting from
           the following items:
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                                                                               64
 19.1.1    Collection of insurance with respect to the Joint Operation, the
           premiums for which have been charged to such operation.
 19.1.2    Sale of geological information, when previously authorized by the
           Parties, provided that the collection of such information was charged
           to the Joint Operation.
 19.1.3    Sale of property, plants, equipment and materials owned by the Joint
           Operation.
 19.1.4    Rental payments received, the reimbursement for claims of customs
           duties and tax or transportation, etc. shall be credited to the Joint
           Operation if such lease payments or reimbursements pertain thereto.
 19.1.5    Any other income from operations or contractual income authorized by
           the Executive Committee on behalf of and for the service of the Joint
           Account.
 19.2      Warranty
           In the event of defective equipment, once the Operator has received
           the corresponding adjustment from the manufacturer or its agents,
           credit shall be made to the Joint Account.
 CLAUSE 20 - DISPOSAL OF EXCESS  MATERIALS AND EQUIPMENT.
 20.1      Excess materials and equipment
           The Operator shall advise the Parties in writing regarding the Joint
           Operation's surplus materials and equipment, thirty (30) days after
           finalizing the inventory that Clause 21 of this Annex refers to. Each
           of the Parties shall designate a representative to review the status
           and establish which materials or equipment are to be put up for sale.
           For the purchase of the useable materials or equipment, ECOPETROL
           shall have the first option and THE ASSOCIATE the second option; these
           options shall be exercised within sixty (60) days following the date
           of notification. In the event that they are not purchased by these,
           the Operator shall report it in writing and they shall be put up for
           auction.
 20.2      Disposal of capital equipment and materials.
           Set forth in Clause 22 (number 22.9) of The Contract, the Operator may
           sell the materials and equipment owned by the Joint Account under the
           following conditions:
 20.2.1    The sale by the Operator to Private Parties of major materials and
           capital equipment that may have been charged to the Joint Account
           shall only be made with the approval of the Executive Committee. The
           revenue shall be credited to the Joint Account. Only for this
           particular purpose, major materials are defined as any asset that has
           an estimated sales value that is greater than the amount that is
           approved by the Executive Committee for such purpose, as a result of
           the request submitted in advance by the Operator, set forth in Clause
           19 (number 19.3.2) of The Contract.
 20.2.2    Minor materials charged to the Joint Account and not required for the
           operation or which are returned to the warehouse, may be sold by the
           Operator and its proceeds shall be credited to the Joint Account.
 20.2.3    For any abandonment and dismantling of the assets whose cost or
           estimated value is greater than the amount approved by the Executive
           Committee for this purpose, as a result of a request presented
           beforehand by the Operator set forth in Clause 19 (number 19.3.2) of
           The Contract, prior authorization by the Executive Committee is
           required.
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                                                                               65
 20.2.4    Neither of the parties is under the obligation to purchase the
           interest of the other in surplus materials, whether they are new or
           second- hand. The withdrawal of major items of surplus materials, such
           as towers, tanks, motors, pumping units and piping shall be subject to
           approval by the Executive Committee. However, the Operator shall have
           the right to dispose of the damaged or useless materials in any
           manner.
 20.2.5    All of the taxes that may be caused on account of the sale or transfer
           of materials or assets from the Joint Account shall be the Operator's
           responsibility, for the account of the Joint Account.
 CLAUSE 21 - INVENTORY
 At ECOPETROL's request, the Operator shall submit the necessary information to
 perform the inventory analyses in warehouses and the Parties shall agree upon
 their joint participation in inventory control. The Operator shall provide the
 ease and cooperation that ECOPETROL may require to carry out the physical task
 of accounting for the fixed assets at the facilities at each Commercial Field,
 prior agreement with the respective Subcommittee, regarding the date, time and
 number of persons who are to perform the inventory.
 21.1      Inventory and Audit
           Set forth in the existing norms and, at least once every three (3)
           years, the Operator shall perform an inventory of all of the Joint
           Operation assets.
 21.2      The notification of the intention of carrying out an inventory shall
           be given by the Operator to the Parties in writing with at least one
           (1) month advance notice to the date on which it is to commence, so
           that the latter can be present. However, non- attendance by one of the
           Parties to carry out the inventory does not jeopardize or reduce the
           validity and effectiveness of the inventory thus carried out by the
           Operator.
 21.3      The Operator shall provide the Parties with a copy of each inventory,
           with a copy of its reconciliation, and shall submit the results to the
           Subcommittees of the Joint Operation, which shall study the report and
           shall propose the actions to be taken in this regard.
 21.4      Inventory adjustments for surpluses or shortfalls shall be brought to
           the attention of the Executive Committee for its consideration and
           approval.
 21.5      With due timing and through midnight of the last day of the term set
           forth as the Exploitation Period, the Parties shall carry out
           inventories of the materials that are in the warehouses and that are
           the property of the Joint Account, as well as of the products produced
           that are in the collection batteries, the pipes that lead from them to
           the storage tanks and in the storage tanks, all within the
           exploitation sites, and such inventories shall be distributed between
           the Parties, after having deducted the royalties, in the same manner
           provided for in Clause 13 of The Contract.
 CLAUSE 22 - AUDIT
 Subject to Clause 17 (number 17.4) in this Agreement, the Parties may, through
 their own auditors or their representatives, examine and control the Operator's
 records related to the joint properties and the operation of these. Similarly,
 ECOPETROL may carry out audits to the records of the Fields exploited by THE
 ASSOCIATE under the sole risk method. In order to facilitate the review of the
 Direct Exploration Costs that Clause 17 (number 17.2.1) of this Agreement refers
 to, once THE ASSOCIATE or the Operator advises the Parties regarding the date on
 which any reimbursable
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                                                                               66
 Exploration Work is to commence, THE ASSOCIATE or the Operator shall allow that,
 prior timely notification, ECOPETROL auditors periodically examine the accounts
 for such Exploration Work, in such a way that, when the existence or not of a
 Commercial Field is accepted, the aforementioned review has already been
 performed under the best conditions of timing and location. In the audit reviews
 that are provided for in this Agreement, in addition to the representatives for
 the Parties, representatives from the Comptroller General of the Republic may
 also intervene, if such organization deems it convenient for this to be the
 case. The costs and expenses of such review shall be for the account of the
 interested Party.
 22.1      Once the audit report is delivered, THE ASSOCIATE or the Operator
           shall have a maximum six (6) month term in order to respond and
           support the objections made. Once this term expires, without the
           Operator having responded, it shall be considered that the objections
           have been accepted and consequently, all shall proceed accordingly.
           The notes or observations from the audit that are not resolved within
           the three (3) months following this term shall be resolved set forth
           in Clause 20 of The Contract.
 CLAUSE 23 - RATE AND FEE CHARTS
 23.1      Subject to the aforementioned limitations, the services rendered to
           the Joint Operation for facilities that are ECOPETROL or THE
           ASSOCIATE's exclusive property, shall be charged at the corresponding
           rates, in order to allow for the recovery of the actual costs. Such
           costs shall include the normal costs for work, salaries, social
           benefits, depreciation and other operational expenses, bearing the
           following in mind:
 23.1.1    The rate for transportation units that is normally calculated, using
           as a basis the time of operation, shall include the time required for
           loading and unloading, the time elapsed waiting to be loaded, and the
           waiting time for unloading to take place. Charges for transportation
           units assigned to the operation shall include Sundays and holidays,
           except when the vehicles are out of service for repairs.
 23.1.2    When the material for aforementioned operations is transported
           together with other materials by river or land fleet that is the
           exclusive property of ECOPETROL or of THE ASSOCIATE, the charge shall
           be made based on the tonnage transported, at rates that are not any
           higher than commercial ones.
 23.2      Rates for the lease of equipment and tools
           The procedure to calculate the lease rate for equipment and tools that
           are the property of the Parties, excluding drilling equipment and
           major equipment, where the rates are to be calculated separately and
           approved by the Executive Committee, shall comprise a value for
           depreciation plus a value for maintenance, and the procedure shall be
           as follows:
 23.2.1    Description, model, number, date of purchase and original cost of the
           equipment.
 23.2.2    Site where the equipment is to be used, reasons for leasing it and
           estimated time of use.
 23.2.3    Value of the annual depreciation for the equipment, calculated based
           on the depreciated book value and its estimated remaining useful life
           (the minimum book value considered shall be ten percent (10%) of the
           original cost, that is to say, the salvage value).
 23.2.4    The annual maintenance value shall be a percentage of the original
           cost, which may vary between five percent (5%) for new equipment and
           up to fifteen percent (15%) for equipment
 <PAGE>
                                                                               67
           that has already been depreciated, depending on the time it has been
           depreciated. For example:
           Equipment A: (Five [5] years of life)
           Time (in years) 1, 2, 3, 4, 5: equipment one hundred percent (100%)
           depreciated
           Maintenance: 5, 6, 7, 8, 9: 15%.
           Equipment B: (Ten [10] years of life)
           Time (in years) 1, 2, 3, 4, 5, 6, 7, 8, 9, 10: equipment one hundred
           percent (100%) depreciated.
           Maintenance: 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15: 15%.
           Note: The time for useful life and depreciation shall be those that
           are established by accounting techniques applicable to oil operations.
 23.2.5    The rate for annual lease is equal to the value provided for in Clause
           23 (number 23.2.3) of this Agreement, plus the one established in
           number 23.2.4 of this same Clause.
 23.2.6    The rate for monthly or daily lease of equipment shall be equal to the
           provided for in Clause 23 (number 23.2.5) in this Agreement, divided
           by twelve (12) or by three hundred and sixty five (365), as
           appropriate.
 23.2.7    No lease charge shall be made for "stand by," but it shall be charged
           to Private Parties.
 23.2.8    The aforementioned lease rates do not include transport, installation,
           operation, lube and fuel costs, which shall be charged to the
           operation that the equipment is destined for.
 23.2.9    The aforementioned lease rates shall be applied to the possible use of
           one hundred percent (100%) equipment and tools owned by the operation,
           THE ASSOCIATE or the Operator, and vice versa.
 23.2.10   In every case, the Subcommittees shall recommend to the Executive
           Committee the use of leased equipment and may apply the rate system
           that the latter may recommend.
 23.2.11   The lease rate for equipment shall be calculated in United States of
           America dollars, but for the respective collection, it shall be
           invoiced in Colombian pesos, at the rate that the Parties may agree
           to.
 23.3      Rate for rental for warehouses and fixed assets
           For the calculation of the lease rate for warehouses that are the
           property of one of the Parties or of the Joint Account, for their
           complete or partial use, a procedure shall be followed which shall be
           agreed to by the respective Subcommittee.
 CLAUSE 24 - CONTRIBUTIONS IN KIND
 ECOPETROL or THE ASSOCIATE shall contribute in kind, those materials that they
 may consider convenient, set forth in the agreements that may be established by
 the Parties.
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                                                                               68
              PART III - ADMINISTRATIVE ASPECTS AND OTHER PROVISIONS
                         Section One - Executive Committee
 CLAUSE 25 - CONDITIONS FOR FUNCTIONING
 For the exercise of its functions, the Executive Committee shall fulfill the
 conditions provided for in Clause 19 of The Contract, as indicated below:
 25.1      The Executive Committee shall be alternately chaired by the Parties,
           beginning with ECOPETROL.
 25.2      The Executive Committee shall name its Secretary, alternating between
           the persons designated by ECOPETROL and by THE ASSOCIATE. The Chair
           and the Secretary shall fall n the same Party.
 25.3      The Executive Committee shall meet in an ordinary manner during the
           months of March, July and November, and in an extraordinary manner
           every time that the Parties and/ or the Operator may consider it
           necessary. At such meetings, the exploitation strategy being carried
           out by the Operator shall be reviewed, as well as the Development Plan
           and the immediate programs and plans. The Executive Committee may be
           attended by the advisors that each of the Parties may consider
           convenient, it being understood that each of the Parties shall bring
           along the smallest possible number of persons.
 25.4      For the ordinary meetings of the Executive Committee, the
           representative entrusted with presiding the following meeting shall
           notify the other representatives (the principal and his alternates) of
           the other Party and of the Operator, with ten (10) days advance notice
           of the date of the meeting, the venue and the issues to be discussed
           (agenda).
 25.5      Pursuant to Clause 18 (number 18.3) of The Contract, both for the
           regular meetings as well as the extraordinary meetings of the
           Executive Committee, the issues to be discussed that have not been
           included in the agenda may be considered during the meeting, prior
           acceptance by the representatives of the Parties on the Committee.
                           Section Two - Sub Committees
 CLAUSE 26 - CREATION OF THE SUBCOMMITTEES
 In development of the function provided for in Clause 19 (number 19.3.4) of The
 Contract, the Executive Committee may create the advisory Subcommittees that it
 may consider necessary. In any case, the Executive Committee shall designate a
 Technical Subcommittee and Financial Subcommittee.
 These Subcommittees shall be the organizations established to control and define
 the technical, financial and legal considerations of The Contract before the
 Executive Committee and shall be governed by The Contract and this Agreement.
 Each Subcommittee shall establish its own internal regulation, approved by the
 Executive Committee.
 CLAUSE 27 - RIGHTS AND OBLIGATIONS
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                                                                               69
 27.1      Set forth in Clause 10 of The Contract, the Operator shall conduct the
           Joint Operations itself, or through its contractors, under the overall
           guidance of the Executive Committee. In any event, the Operator shall
           be responsible for the Joint Operation, set forth in the provisions of
           The Contract.
 27.2      The following are among the Operator's obligations:
 27.2.1    The preparation, presentation and implementation of the Development
           Plan, the Budgets and Exploration and Exploitation Programs, as well
           as for the approval of expenses.
 27.2.2    The direction and control of all statistics and accounting services.
 27.2.3    Planning and obtaining all services and materials required for the
           proper development of the Joint Operation.
 27.2.4    Providing all the technical skill and consulting required for the
           efficient development of the Joint Operation.
 27.2.5    Planning the tax effects and fulfilling all tax obligations that may
           be derived from the operations performed and providing the timely
           report to the Parties for the proportion that corresponds to each of
           them.
 27.2.6    Establishing a bank account for the exclusive management of the Joint
           Account resources.
 27.3      The Operator may not establish any encumbrance whatsoever on the
           properties of the Joint Operation.
 27.4      The resignation or removal of the Operator may be made without
           prejudice of any right, obligation or responsibility acquired during
           the time in which the Operator acted as such; if the Operator resigns
           or is removed before fulfilling the obligations established in The
           Contract, it may not charge the Joint Account for the costs and
           expenses in which it incurred on account of the change. But if the
           Executive Committee were to approve them, these charges and expenses
           may then be charged to the Joint Account.
 27.5      Once the Operator is notified of his removal or of the acceptance of
           its resignation, for the transfer or responsibilities, ECOPETROL shall
           audit the Joint Account and shall perform an inventory of all of the
           properties of the Joint Operation. Such inventory shall be used for
           purposes or return and accounting for the procedure of such transfer
           or responsibilities. All costs and expenses incurred with respect to
           such inventory and audit shall be for the account of the Joint
           Account.
 27.6      The Operator shall not be responsible for any loss or damage on
           account of the Joint Operation, unless such damages or losses are the
           result of:
 27.6.1    Gross negligence by the Operator
 27.6.2    Failure to obtain and maintain any of the insurance required in Clause
           33 of The Contract, except when the Operator has made all possible
           efforts to obtain it and maintain them, and the results of such
           efforts have been fruitless, a situation which the Operator must first
           communicate to the Parties in writing.
 <PAGE>
                                                                               70
                       Section Four - Contracting Procedure
 CLAUSE 28 - SUPPLIER REGISTRATION AND BIDDERS LIST
 28.1      It shall be the Operator's responsibility to maintain an updated
           registration of vendors, classified pursuant to the various activities
           that the operation may require, as well as to establish the
           qualification criteria for the firms to be included in the bidders'
           list. The respective Subcommittee may request a review of the criteria
           before approving the bidders' list.
 28.2      ECOPETROL may review the Operator's vendor registration on an annual
           basis and may suggest to it, through the respective Subcommittee, that
           vendors be included or excluded from the registration. Despite the
           above, ECOPETROL may, at any time, by means of a request that duly
           explains the motives, request the withdrawal of persons or entities
           from the registration.
 28.3      In all cases that imply soliciting proposals to contract, the vendor
           registration shall be consulted, recording a statement on the
           corresponding document.
 28.4      The persons or entities that are included in the vendor registration
           shall accredit technical, moral and economic solvency, in addition to
           the experience, not only of the company but that of its partners as
           well, and also that of its technicians that are permanently hired by
           it.
 28.5      Set forth in the aforementioned criteria, the Operator shall establish
           a registration of qualified vendors, which shall be updated
           periodically, set forth in their performance.
 28.6      In the Fields that are exploited under the sole risk, THE ASSOCIATE
           shall have the right that is provided for in Clause 10 (number 10.6)
           of The Contract.
 CLAUSE 29 - BIDDING PROCESS
 29.1      Responsibility: The Operator shall be responsible for preparing the
           Request for Proposals in due time, and shall submit it to
           consideration by the corresponding Subcommittee.
 29.2      The list of those invited to submit proposals shall be prepared based
           on the information in the Registration of Vendors.
 29.3      In every bidding process, the Operator shall invite at least three
           companies. If this were not to be possible, a statement shall be made
           with respect to the justification in the report of recommendations to
           the respective Subcommittee.
 29.4      It shall be endeavored not to invite more than six (6) companies, in
           order to avoid additional costs in the assessment of the proposals
           and, similarly, to provide a greater opportunity to the participating
           companies to successfully obtain the respective contract.
 29.5      All other factors being the same, the order of priorities to be
           included in the list of bidder shall be as follows: - Companies
           registered and with headquarters in the department or departments
           where the Commercial Field or Fields are located, but with a branch
           established in such department. - Colombian companies whose
           headquarters are outside the department or departments where the
           Commercial Field or Fields are located, but with a branch established
           in such department. - Foreign companies with a branch in Colombia. -
           Foreign companies that do not have a branch in Colombia.
 <PAGE>
                                                                               71
 29.6      In the list of companies to be invited to submit proposals, those
           companies that are technically and commercially qualified and that
           have not had the opportunity to participate in similar bids in the
           past shall also be kept in mind.
 29.7      The Operator shall prepare the bid documents and shall submit these to
           the consideration of the respective Subcommittee with sufficient
           advance notice.
 29.8      It shall be clearly expressed in the bidding documents that:
 29.8.1    Cost shall be one of the criteria to be considered, though not the
           sole one, for the award of the contract;
 29.8.2    The assessment of the bid shall bear in mind other factors other than
           cost, which shall be included in the bid documents;
 29.8.3    All proposals that exceed the range of real cost for this activity
           shall be disqualified;
 29.8.4    The proposals are to be submitted set forth in the terms of the
           invitation, and the failure to observe this requirement may lead to
           not being considered as valid proposals;
 29.8.5    The request for proposals shall include a table with the details of
           the prices which is to be filled out by the bidders, in order to
           facilitate comparing the proposals;
 29.9      The list of bidders shall be reviewed and approved by the Technical
           Subcommittee before the invitations to bid are sent out.
 29.10     Once the bid documents have been distributed, the following rules
           shall apply:
 29.10.1   Any information, modification or clarification of the original bid
           documents shall be sent out to all the bidders. The Procurement and
           Supplies Department of the Operator shall be responsible for these
           changes. The changes shall be duly justified by means of a document in
           writing.
 29.10.2   No bidders can be added or deleted from the list of bidders originally
           approved by the corresponding Subcommittee.
 29.10.3   Any bidder that does not abide by the bid procedures and rules, or
           that may violate the Operator's business ethics code shall be
           disqualified immediately.
 29.11     The content and format for all of the materials in a request for
           proposals shall fulfill the requirements of the procedure known as
           "Documentation format submitted to the Technical Subcommittee" and
           shall be submitted to the consideration of the corresponding
           Subcommittee.
 29.12     The internal approvals that are required by the Operator and by
           ECOPETROL depend on the estimated value of the contract, set forth in
           the internal procedures of the former and the latter.
 CLAUSE 30 - AWARDS OF CONTRACTS AND PURCHASE ORDERS
 30.1      The Operator is responsible for awarding bids for contracts and
           purchase orders. For this purpose, it shall submit its recommendation
           to the respective Subcommittee, subject to the procedures that have
           been established by the Executive Committee for this purpose.
 <PAGE>
                                                                               72
 30.2      Value: The awards shall be based on the best global (overall) value.
           The lowest price does not always mean the best proposal, since, in
           addition to the amount, other aspects are borne in mind, such as
           scheduling and quality, experience, reputation and the Colombian
           content submitted by the bidder. In the event that the contract is not
           awarded to the lowest amount proposal, such decision should be
           justified.
 30.3      Justification in writing: The Operator shall present a recommendation
           in writing to the corresponding Subcommittee, justifying the contract
           and purchase order award, subject to the procedures that are
           established for such purpose by the Executive Committee. Such
           justification shall include a summary of the commercial and technical
           assessments of the proposals received and the basis for the Operator's
           recommendation.
 30.4      Direct contracting: Direct contracting shall be supported and
           presented in writing to the respective Subcommittees, clearly
           identifying their justification. The Operator may contract directly,
           without having to go through a bidding process, in any of the
           following events:
 30.4.1    When only one vendor can be obtained, within the time frame required
           to satisfy the project schedule;
 30.4.2    When an item or service Contract before in a direct manner does not
           have an equivalent or satisfactory substitute;
 30.4.3    When a service or work is derived from a previous one or is an
           extension to an existing contract or work order issued during the last
           ninety days and the commercial conditions are not modified, or when
           the evidence stemming from a recent bid justify contracting without
           undergoing a bidding process;
 30.4.4    When the Operator has standardized a specific item or service for all
           of the applications within its are of operations and there is only one
           known vendor for such item or service;
 30.4.5    When it is considered that a sole item or service fulfills the
           Operator's requirements within a specified delivery time period;
 30.4.6    When an item or service is obtained for testing or assessment;
 30.4.7    When there is an emergency. The Operator shall notify ECOPETROL at the
           corresponding Subcommittee's immediately next meeting after such
           emergency.
 30.5      Partial awards: A bid can be awarded partially to two or more bidders,
           provided that all of the following conditions are met:
 30.5.1    The possibility of a partial award is specifically indicated in the
           request for proposals;
 30.5.2    The successful bidders have fulfilled the requirements established in
           the Request for Proposals;
 30.5.3    The partial award represents the best value for the items or services
           that shall be obtained;
 30.5.4    Any change in the scope of work or in the award criteria shall be
           clearly communicated to all of the bidders before the partial award.
 30.6      Rejection of proposals: The Operator may declare a bid null and void
           when the respective Subcommittee finds motives to justify such
           decision and/ or when the proposals are out of line with the actual
           costs.
 30.7      Notification to the unsuccessful bidders: The result of the award
           shall be communicated in writing to all participants.
 <PAGE>
                                                                               73
 30.8      Clarification: During the assessment period, the Operator may request
           clarification from the bidders. The Technical Subcommittee shall
           approve the significant commercial clarifications. No new approval
           shall be required by the respective Subcommittee when clarifications
           refer to technical issues. Clarifications that may affect the bid
           shall be communicated in writing to all of the bidders.
 CLAUSE 31 - MANAGEMENT OF CONTRACT AND WORK ORDER
 31.1      The Operator shall be responsible for managing the contracts and
           purchase orders during their execution.
 31.2      The bases for contract or purchase order management are their
           execution itself, which shall include all of the agreed- to prices,
           schedule and quality requirements.
 31.3      The Operator shall maintain a written record of all modifications to
           the original contract. The cost impact for each change to the contract
           shall be assessed by the Operator and negotiated with the vendor or
           contractor before the contract price is changed.
 31.4      Any change in the initially approved value of the contract shall be
           subject to consideration by the respective Subcommittees and, if
           required, shall be approved by the Executive Committee, set forth in
           the procedure that is established for such purpose by the Executive
           Committee.
 31.5      The Operator is responsible for cost control.
 31.6      Any additional work or job under the terms of the contract shall be
           authorized by the Operator's Project Manager or Operations Manager,
           who shall consult with the Procurement and Logistics Manager or with
           the departments that fulfill these functions, before making any
           modification to the contract. This dual responsibility ensures control
           for the integrity of the change process. In the event that the changes
           imply modifications to the text of the contract, these shall be
           submitted to approval by the Operator's Legal Department.
 31.7      Quality control shall be managed with the QA/QC (Quality Control /
           Quality Assurance) process, which shall include the independent
           inspection and verification of the work and shall be performed at
           appropriate moments during the execution of the work.
 31.8      The processes used by the Operator for cost control shall be described
           in a cost control procedure.
 31.9      The Parties shall receive a monthly report on work progress, with cost
           documentation and schedule, including the analysis of the variations
           with respect to the originally agreed- to Budget for the main
           contracts and purchase orders.
 31.10     Once the main contracts and purchase orders have been executed, a
           detailed analysis shall be undertaken to assess the experiences
           learned that could be applied to similar contracts or work orders, and
           also in order to allow for improvements in their control.
 CLAUSE 32 - INSURANCE
 For purposes of Clause 33 in the Contract, with respect to Insurance, the
 Operator shall deliver the following information to ECOPETROL, for the latter to
 insure fifty percent (50%) of the assets corresponding to the Commercial Field:
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                                                                               74
 32.1      Description of the assets, differentiated, inasmuch as possible, as
           follows:
 32.1.1    Offices, camps and other non- industrial facilities
 32.1.2    Collection stations, specifying tanks (number and capacity) and other
           equipment.
 32.1.3    Diverse warehouses and other facilities
 Note:     The external pipelines and the wells are not insured under the fire
           policy, since, in this case,
 ECOPETROL assumes the risk directly.
 32.2 Value of the assets, indicating only the value of the part that belongs to
 ECOPETROL and indicating the percentage of the value that it represents.
 32.2      Geographic location.
 32.4      Date of receipt, as of which the risk is transferred to the Joint
           Operation.
 CLAUSE 33 - FORCE MAJEURE OR ACTS OF GOD
 33.1      Clause 34 of The Contract only suspends fulfillment of those specific
           obligations whose performance becomes impossible on account of events
           that constitute force majeure or acts of God. Similarly, it only
           interrupts the obligations on the assets, properties, production
           facilities, etc. that are affected by the aforementioned circumstance.
           The affected Party shall notify the termination of the force majeure,
           providing details on the magnitude of the damages and the corrective
           actions that affect the system.
 33.2      If one of the Parties cannot, on account of force majeure or acts of
           God, fulfill the obligations of this Contract, it shall notify this to
           the other Party for its consideration, within ten (10) working days
           following the date on which the cause was produced, specifying the
           causes of its impediment, the estimated period of suspension of the
           activities and the way in which it affects fulfillment of the
           corresponding affected obligation. The other Party shall respond in
           writing, either accepting the cause or not for force majeure or acts
           of God.
 33.3      The Party affected by the cause for force majeure or acts of God shall
           recommence fulfillment of the affected obligations within a reasonable
           term once such cause has disappeared, for which it shall advise the
           other Party within ten (10) working days after the cause has
           disappeared. In the event of partial or delayed execution of the
           obligation affected by force majeure or acts of God, the Party that is
           obligated to its fulfillment shall exert its best efforts to execute
           it within the terms and conditions agreed- to between the Parties in
           this Contract, having to continue with the fulfillment of the
           remaining contractual obligations.
 33.4      If the force majeure cause were to affect the execution of any of the
           Exploration Work agreed to as part of the exploratory activities that
           Clause 5 of this Contract refers to, the guarantee that supports the
           fulfillment of the affected Exploration Work shall be extended for the
           same period of time that the impediment may last, which were not
           executed during this period of time. For such purpose, THE ASSOCIATE
           shall extend or substitute such guarantee, as the case may be.
 <PAGE>
                                                                               75
 CLAUSE 34 - REVISION OF THE OPERATIONS AGREEMENT
 This Operations Agreement may be revised when the Parties consider it convenient
 to do so, at the request of any of the Parties. For its revision or
 modifications the Executive Committee is fully empowered to do so. This
 Operations Agreement shall be valid until one of the following events occurs:
 34.1      Termination of The Contract
 34.2      Agreement in writing between the Parties
 34.3      The signing of a new Agreement.
 In faith of the previously mentioned, the Parties sign the present Operations
 Agreement, in contract paper of ECOPETROL on the twentieth (20) day of the month
 of December of the year two thousand two (2002).
                          EMPRESA COLOMBIANA DE PETROLEOS
                                     ECOPETROL
                                (Signed) illegible
                              ALBERTO CALDERON ZULETA
                                     President
                            HARKEN DE COLOMBIA LIMITED
                                (Signed) illegible
                          GABRIEL GUSTAVO CANO VELASQUEZ
                          Principal Legal Representative
                                     WITNESSES
              (Signed) Illegible                (Signed) Illegible
             VICTOR EDUARDO PEREZ                   ALBERTO TOVAR
 <PAGE>
                                                                               76
                                         ANNEX C - LINEAMENTS FOR THE PREPARATION
                                                          OF THE DEVELOPMENT PLAN
                     ANNEX C - LINEAMENTS FOR THE PREPARATION
                              OF THE DEVELOPMENT PLAN
 The present Annex establishes the main aspects that must be considered for the
 preparation of the initial Development Plan and of the programs, projects and
 annual Budget for each of the Fields discovered in the development of The
 Contract, which shall be subject to the consideration of ECOPETROL. In this
 document the general conditions of the Development Plan are described without
 including a detailed explanation of the format or of the level of detail to be
 presented, further than the coverage of the main issues identified herein.
 Additional information may be presented in each Development Plan as it is
 considered appropriate.
 A.   INITIAL DEVELOPMENT PLAN
 1.   Outline of the Development Strategy
      Summary of the background of the Field, of the development strategy and of
      the most relevant aspects of the economic and commercial conclusions.
 2.   Description of the Field
      Includes the geological synthesis of the Reservoirs discovered and the
      determination of the geometry of the field. In this section the area
      capable of producing Hydrocarbons of the different Reservoirs is determined
      and the commercial area is delimited, using the plain Gauss coordinates, by
      the projection in surface of the lowest level of Hydrocarbons commercially
      exploitable.
 3.   Reservoir Engineering
      This implies the evaluation of the properties of the rocks and of the
      fluids contained in the Field Reservoirs and other analysis that conduce
      to:
      a)   Determine the original volumes of Hydrocarbons in each Reservoir, the
           tested, probable and possible Reservoirs of the Field (in each case,
           based on its useful life, independently from the duration of the
           Exploitation Period established in The Contract) and discriminated by
           Liquid Hydrocarbons and Gas Hydrocarbons.
      b)   Establish the forecast for production of Hydrocarbons that THE
           ASSOCIATE expects to produce during each year of exploitation of the
           Field, both for the tested Reservoirs and for the tested Reservoirs
           plus those probable.
      c)   Define the strategy for exploitation so that the production profile,
           in the case of tested Reservoirs, achieves the Maximum Degree of
           Productive Efficiency (MER) or the top of the production, in that case
           in which THE ASSOCIATE identifies restrictions to achieve he MER, and
           expose the preliminary strategy of exploitation of the probable
           Reservoirs.
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                                                                               77
      d)   Specify the program of obtainment of information to be executed for
           the adequate administration of the Reservoirs.
 4.   Criteria of the Design of the Development Plan
      Description of the logics and coherence of the Development plan and
      synopsis of the criteria, bases and presumptives taken into consideration
      for the design of the plan.
 5.   Development Drilling and Completion
      Back ground of the main aspects that refer to the drilling and completion
      of Development Wells.
 6.   Surface Installations
      Presentation of the options of development that were taken into account,
      the justification of the option chosen, its general specifications, key
      aspects and diagram of each of the Production Systems; Treatment and
      Storage; Transportation and Transfer, and of Support to the production of
      Hydrocarbons that come from the Field.
 7.   Construction and Assembly
      Explanation of the strategy for the Development drilling and the
      construction and assembly of the surface facilities and the assurance of
      the quality.
 8.   Operation and Maintenance
      General Description of the scheme and logistics of the operation with its
      corresponding proposal of the Organizational Letter for the handling of the
      field with a background of the contingency plans for the control of the
      critical factors.
 9.   Abandonment of the Field and Restoration of the Area
      Synthesis of the program, methods and practices foreseen for the
      abandonment of the wells and the withdrawals of the surface facilities and
      alternatives considered for the provision of funds for the abandonment of
      the field and the recuperation of the area
 10.  Economic and Commercial Aspects.
      They include the evaluation of the commercialization options of the
      Hydrocarbons discovered, the economic viability of the Field and the
      reasons why such alternative was chosen. It must also include:
      a)   Estimate of the Direct Exploration Costs incurred in before the
           presentation of the initial Development Plan.
 <PAGE>
                                                                               78
      b)   Annual budget and chronogram for disbursements on account of capital
           expenses (investments) and operational (Direct and Indirect Expenses)
           in current dollars during the exploitation of the Field, with relation
           to the Reservoirs tested and the Reservoirs tested plus those
           probable.
      c)   Main economic indicators obtained in the economic evaluation and
           optimization carried out for the determination of the commerciality of
           the Field.
      d)   When it is necessary to unify the field or when the design of the
           Development Plan suggests the need to share the production facilities
           of the Field with other Fields discovered in the development of the
           same Contract, or of another Association Contract, the proposal of a
           unified exploitation plan that THE ASSOCIATE proposes to submit for
           the consideration of others interested and/or the proposal of the
           agreement to share facilities or other assets, including cost
           assignments and other distributions necessary, must be attached.
 B.   PROGRAMS, PROJECTS AND ANNUAL BUDGET
 The Operator, or THE ASSOCIATE if concerning a field exploited under the
 modality of only risk, pursuant to that established in The Contract and in the
 Operating Agreement (Annex B), shall prepare and present to the Parties the
 proposal of the programs, projects and Budget for the following calendar year,
 pursuant to the initial Development Plan accepted for the field.
 For all effects of the presentation of the annual programs and projects, by
 program it is understood the group of projects to be developed, or that by their
 technical, operational and administrative characteristics deserve to be
 controlled in a joint manner (for example: Building of Battery X). Each program
 includes the presentation of the projects to be carried out, their sequence of
 execution and the general conditions to which they must abide by to obtain a
 determined result.
 By project it is understood the group of activities proper of a work or an
 specific necessary work for the development and production of the field.
 (example: Civil work, Access roads, Facilities, Separation and Treatment System,
 etc.). Each project shall be duly supported with the explanatory documents and
 the technical and economic specifications.
 The annual Budget shall be divided into Expense Budget and Investment Budget.
 For all effects of the presentation, the Expense Budget shall be divided into
 programs, groups and concepts of expenses and that of Investments in programs
 and projects, in numerical order and continuous within each section of the
 Budget. With respect to the Expense Budget, the programs and projects shall be
 divided into expense groups and these into concept of expenses. By expense
 groups it is understood the purpose or object of the expense (for example
 Personnel Expenses) and by concept of expenses the specific assignment granted
 (for example: Salaries, Social Benefits).
               EXAMPLE OF THE INDEX OF THE INITIAL DEVELOPMENT PLAN
 1.   Development Scheme of the field
      .    History and Location of the Field
      .    Development Strategy
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                                                                               79
      .    Production Curve and Investment and Expense Program
      .    Commercial and Economic Conclusions
 2.   Description of the Field
      .    Geology
           .    Regional Frame
           .    Local Frame
           .    Structural
           .    Geology of Reservoirs (Stratigraphy, Sedimentology and factors
                that control the quality of the reservoir)
      .    Geophysics - Seismic Information
           .    Seismic Data Base
           .    Seismic Data Processing
           .    Analysis and Interpretation of Seismic Data
      .    Petrophysics
           .    Subsurface Logging Information
           .    Data on recovered Nucleus
           .    Calibration of the information on Logs and Nucleus
           .    Analysis and Interpretation of Petrophysical data
      .    Maps and Geological Patterns
           .    Isopachous
           .    Structural
           .    Isoporosity
           .    Others
 <PAGE>
                                                                               80
 3.   Reservoir Engineering
      .    Basic Reservoir Information
           .    Rock Properties
           .    Fluid Properties
           .    Analysis of Nucleus and PVT
           .    Gas-Oil and Oil-Water Contacts
           .    Productivity of the wells
      .    Simulation of Reservoirs
           .    Models of Reservoirs
           .    Predictions
      .    Original Hydrocarbons "in-situ". OOIP and OGIP
           .    Uncertainties
      .    Calculation of Reservoirs (scenarios for Tested, Probable and Possible
           Reserves)
      .    Production Forecasts (of Tested Reservoirs and of Tested plus
           Probable)
      .    Exploitation Strategy
           .    Development Wells Spacing (Productive and Injectors)
           .    Pressure Maintenance Projects
      .    Conservation and/or Use of Gas
      .    Administration of Reservoirs and Obtainment of Data
           .    Well Testing
           .    Pressure Measurement and Fluid Sampling
           .    Coring and Logging
           .    Production Behavior
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                                                                               81
           .    Production Optimization
      .    Projects of Improved Recovery
      .    Opportunities for Future Developments
           .    Well Testing
 4.   Criteria of the Design of the Development Plan
      .    Logics of the Design
      .    Regulations and Standards Observed
      .    Environmental Criteria
           .    Environmental Diagnostic and Impacts
           .    Operational Limits
      .    Functional Criteria
           .    Production Mechanisms of the Reservoirs
           .    Flow Rates and Production Capacities
           .    Useful Life
           .    Specifications of the fluids produced
      .    Geotechnical Criteria
 5.   Development Drilling and Completion
      .    Development wells
           .    Location
           .    Design of the Wells (pursuant to the purpose of the well, type
                and trajectory of the hole.
           .    Drilling Strategy and Chronogram
           .    Critical success factors (technical and operational)
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                                                                               82
      .    Completion of Wells under Development
           .    Design of the completion of Producer and Injector Wells
           .    Artificial Lifting
      .    Subsequent Operations
           .    Overhauling
           .    Stimulation
 6.   Surface Installations (Diagram, Specifications and Key Aspects)
      .    Production System
           .    Systems considered
           .    Justification of the system(s) proposed
           .    Sub-system of Pressure Maintenance
           .    Improved Recovery
      .    Treatment and Storing System
           .    Gathering
           .    Separation and Treatment
           .    Measurement and Sampling
           .    Water, gas and impurities disposition
           .    Storing
           .    Pumping
      .    Support Systems
           .    Safety and Control of the Production
           .    Telecommunications
           .    Power Generation
           .    Camping, Warehouses, workshops, Offices and Transportation
                Terminals
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                                                                               83
      .    Transportation System and Transference of Hydrocarbons.
 7.   Construction and Assembly
      .    Strategy
           .    Coordination of Activities
           .    Permissions and Licenses required
           .    Construction and Assembly Chronogram
           .    Required Services
      .    Quality Assurance and Control
 8.   Operation and Maintenance
      .    Proposal of an Organizational Letter of the Field
      .    Operational Limits of the surface and subsurface systems.
      .    General Vision of the Logistics of the Operation
           .    Production
           .    Health, Safety and Environmental Monitoring
           .    Relations with the Community and the Government
           .    Personnel lodging
           .    Warehouses
           .    Materials and Supplies
           .    Displacement and Transportation
           .    Communications
           .    Others
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                                                                               84
      .    Contingency Plans
           .    Evaluation of Operational Risks
           .    Organization and Training for Emergencies Response
 9.   Abandonment of the field and Restoration of the Area
      .    Methods and Practices of Abandonment and withdrawal of installations
           .    Development Wells (Producers and Injectors)
           .    Surface Installations
      .    Restoration and recuperation of the area
 10.  Economic and Commercial Aspects
      .    Commercialization
           .    Market Opportunities and Options considered
           .    Justification of the Option(s) proposed
           .    Estimation of Incomes
           .    Critical success factors
      .    Direct Exploration Costs caused before the design of the Plan
           .    Acquisition of Seismic Information
           .    Exploratory Wells
      .    Estimation of Capital Costs and Operation Expenses
           .    Investments (Distributed between the main operations or goods)
           .    Direct Expenses (Distributed between the main activities)
           .    Indirect Expenses
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                                                                               85
      .    Disbursement Chronograms
           .    Investments
           .    Expenses
           .    Total
      .    Economic Analysis and Evaluation of the project
           .    Economic Indicators
           .    Sensibility Analysis
           .    Exploratory Wells
 </TEXT>
 </DOCUMENT>