<PAGE>   1
               FIRST AMENDMENT TO NOTE PURCHASE AND LOAN AGREEMENT

         THIS FIRST AMENDMENT TO NOTE PURCHASE AND LOAN AGREEMENT is made
effective the 9th day of July, 2001, between SEVEN SEAS PETROLEUM INC., a Cayman
Islands exempted company limited by shares (the "Corporation"), all of the
Corporation's Subsidiaries (as hereafter defined) and CHESAPEAKE ENERGY
CORPORATION, an Oklahoma corporation (the "Lender").

                                   WITNESSETH:

         WHEREAS, the Corporation, the Subsidiaries and the Lender executed that
certain Note Purchase and Loan Agreement dated effective July 9, 2001, (the
"Agreement"), providing for a credit facility made available by the Lender to
the Corporation in the original principal amount of TWENTY- TWO MILLION FIVE
HUNDRED THOUSAND DOLLARS ($22,500,000.00); and

         WHEREAS, the Corporation, the Subsidiaries and the Lender desire to
modify the terms of the Agreement to correctly designate the exhibits and
schedules to the Agreement, subject to the terms and conditions contained in the
Agreement as amended by this First Amendment to Note Purchase and Loan Agreement
(the "Amendment").

         NOW, THEREFORE, in consideration of the mutual covenants among the
parties hereto and the benefits realized therefrom by the Corporation, the
Subsidiaries and the Lender, the parties hereby agree as follows:

1. Defined Terms. Except as otherwise defined herein, all terms defined in the
Agreement will have the same meaning herein as such terms are defined in the
Agreement.

2. Extension of Closing Date. The date July 23, 2001, in clause (b) of paragraph
2 of the Agreement is hereby deleted and the date July 24, 2001, is hereby
substituted therefore.

3. Amendment of Exhibit "B". The form of Warrants attached to the Agreement as
Exhibit "B" is hereby deleted and the form of Warrants attached hereto as
Exhibit "B" is hereby substituted therefor.

4. Addition of Remaining Exhibits. The following exhibits to the Agreement which
were not finalized are added as follows: (a) the form of CEC Note attached
hereto as Exhibit "A" is hereby added to the Agreement as Exhibit "A"; (b) the
forms comprising the Pledge Agreement attached hereto as Exhibit "C" are hereby
added to the Agreement as Exhibit "C"; (c) the form of Registration Agreement
attached hereto as Exhibit "E" is hereby added to the Agreement as Exhibit "E";
(d) the form of Collateral Sharing Agreement attached hereto as Exhibit "F" is
hereby added to the Agreement as Exhibit "F"; and (e) the form of Loan Purchase
Agreement attached hereto as Exhibit "G" is hereby added to the Agreement as
Exhibit "G".

5. Post Closing Actions. Under the terms of the Agreement the Corporation is
required among other things to (the "Deferred Post Closing Requirements"): (a)
amend the articles of incorporation,

SEVEN SEAS PETROLEUM INC.
FIRST AMENDMENT-NOTE PURCHASE AGREEMENT


<PAGE>   2

other formation documents and governance documents for each of the Subsidiaries
as required under paragraph 5.15 of the Agreement, which the parties have agreed
will be modified as provided in Schedule "1" attached as a part hereof; and (b)
establish controlled deposit accounts as contemplated by paragraphs 5.14 of the
Agreement. The Corporation has advised that due to timing considerations the
Deferred Post Closing Requirements cannot be completed prior to the Closing Date
and subject to the terms and conditions herein the Lender has agreed to waive
the Deferred Post Closing Requirements as a condition to closing the CEC Loan.
Notwithstanding the foregoing, the Corporation and the Subsidiaries agree to
comply with the Deferred Post Closing Requirements on or before the date which
is forty-five (45) days after the Closing Date. The parties expressly agree that
the Lender does not waive any other conditions to the Closing except as
expressly provided herein, that the Lender does not waive any covenants
(including those that impact the Deferred Post Closing Requirements), that the
obligation of the Corporation and the Subsidiaries to perform the Deferred Post
Closing Requirements is only deferred and that failure to perform such
obligations on or before the specified date will constitute an event of Default
under the Agreement, the Note and the Related Documents.

6. Representations, Warranties and Covenants. In order to induce the Lender to
enter into this Amendment to modify the Agreement, the Corporation and
Subsidiaries hereby represent, warrant and covenant that:

   6.1 No Default. Each of the representations and warranties set forth in the
       Agreement and in this Amendment are true and correct on and as of the
       date of execution of this Amendment with the same effect as if such
       representations and warranties had been made on and as of the date of
       execution hereof and no event of Default has occurred or is continuing.

   6.2 Authorization. The Corporation and each of the Subsidiaries is duly
       authorized to execute and deliver this Amendment and is and will continue
       to be duly authorized to borrow monies and to perform such party's
       obligations under the Agreement and the Related Agreements. The
       Corporation and the Subsidiaries have duly taken all corporate action
       necessary to authorize the execution and delivery of this Amendment and
       to authorize the performance of the obligations of Corporation and the
       Subsidiaries hereunder.

   6.3 No Conflicts. Except for those which have been obtained, no consent,
       approval, authorization or order of any court or governmental authority
       or third party is required in connection with the execution and delivery
       by the Corporation of this Amendment or to consummate the transactions
       contemplated hereby.

   6.4 Binding Effect. When duly executed and delivered, this Amendment and the
       Agreement will each be a legal and binding obligation of Corporation and
       the Subsidiaries, enforceable in accordance with its terms, except as
       limited by bankruptcy, insolvency or similar laws of general application
       relating to the enforcement of creditors' rights and by equitable
       principles of general application.


SEVEN SEAS PETROLEUM INC.
FIRST AMENDMENT-NOTE PURCHASE AGREEMENT

                                     - 2 -

<PAGE>   3

7. Supersession. It is agreed and understood between the Corporation, the
Subsidiaries and the Lender that: (a) except to the extent the Agreement and
Related Agreements are amended by this Amendment, such documents will remain in
full force and effect and unabated and will govern all obligations throughout
the term of the Agreement and this Amendment; (b) the Agreement together with
all amendments thereto and all Related Agreements are incorporated herein by
reference and made a part of this Amendment and the Corporation and the
Subsidiaries hereby adopt, confirm and reaffirm each and every representation,
warranty, covenant and obligation set forth in the Agreement and the Related
Agreements as fully as if each of such matters were restated and set forth in
this Amendment; (c) the Agreement as amended by this Amendment and the Related
Agreements supersede any and all prior agreements entered into between the
Corporation, the Subsidiaries and the Lender; and (d) whenever the Agreement,
the Related Agreements or any agreement or document executed in connection
therewith refer to the Agreement it is intended that such reference is to the
Agreement as amended by this Amendment.

8. Default. The Corporation, the Subsidiaries and the Lender agree that any
breach by the Corporation or the Subsidiaries of any of the terms or conditions
of the Agreement as amended by this Amendment will constitute an event of
Default under the Agreement.

9. Counterparts. This Amendment may be executed in multiple counterparts, each
of which will be an original instrument, but all of which will constitute one
agreement.

10. Governing Law. This Amendment will be governed by and construed in
accordance the laws of the State of Oklahoma and any applicable laws of the
United States of America in all respects, including construction, validity and
performance.

         IN WITNESS WHEREOF, the parties hereto have caused this Amendment to be
duly executed effective as of the date first above written.

                                SEVEN SEAS PETROLEUM INC., a Cayman
                                Islands exempted company limited by shares


                                By /s/ LARRY A. RAY
                                  ----------------------------------------------
                                  Larry A. Ray, President

                                (the "Corporation")

                                SEVEN SEAS PETROLEUM HOLDINGS INC.,
                                a Cayman Islands exempted company limited by
                                shares

                                By /s/ LARRY A. RAY
                                  ----------------------------------------------
                                  Larry A. Ray, President


SEVEN SEAS PETROLEUM INC.
FIRST AMENDMENT-NOTE PURCHASE AGREEMENT
                                     - 3 -

<PAGE>   4


                                SEVEN SEAS PETROLEUM TURKEY INC., a
                                British Columbia corporation


                                By /s/ LARRY A. RAY
                                  ----------------------------------------------
                                  Larry A. Ray, President

                                SEVEN SEAS RESOURCES AUSTRALIA  INC.,
                                a British Columbia corporation


                                By /s/ LARRY A. RAY
                                  ----------------------------------------------
                                  Larry A. Ray, President

                                SEVEN SEAS PETROLEUM USA INC., a
                                Delaware corporation


                                By /s/ LARRY A. RAY
                                  ----------------------------------------------
                                  Larry A. Ray, President

                                SEVEN SEAS PETROLEUM AUSTRALIA INC.,
                                a Cayman Islands exempted company limited by
                                shares


                                By /s/ LARRY A. RAY
                                  ----------------------------------------------
                                  Larry A. Ray, President

                                SEVEN SEAS PETROLEUM PNG INC., a
                                Cayman Islands exempted company limited by
                                shares


                                By /s/ LARRY A. RAY
                                  ----------------------------------------------
                                  Larry A. Ray, President

                                SEVEN SEAS PETROLEUM ARGENTINA INC.,
                                a Cayman Islands exempted company limited by
                                shares


                                By /s/ LARRY A. RAY
                                  ----------------------------------------------
                                  Larry A. Ray, President



SEVEN SEAS PETROLEUM INC.
FIRST AMENDMENT-NOTE PURCHASE AGREEMENT
                                     - 4 -

<PAGE>   5

                                SEVEN SEAS PETROLEUM
                                MEDITERRANEAN  INC., a Cayman Islands
                                exempted company limited by shares


                                By /s/ LARRY A. RAY
                                  ----------------------------------------------
                                  Larry A. Ray, President

                                SEVEN SEAS PETROLEUM TURKEY, INC., a
                                Cayman Islands exempted company limited by
                                shares


                                By /s/ LARRY A. RAY
                                  ----------------------------------------------
                                  Larry A. Ray, President

                                SEVEN SEAS PETROLEUM COLOMBIA INC.,
                                a Cayman Islands exempted company limited by
                                shares


                                By /s/ LARRY A. RAY
                                  ----------------------------------------------
                                  Larry A. Ray, President

                                PETROLINSON S.A., a Panamanian corporation


                                By /s/ LARRY A. RAY
                                  ----------------------------------------------
                                  Larry A. Ray, President

                                GHK COMPANY COLOMBIA, an Oklahoma
                                corporation


                                By /s/ LARRY A. RAY
                                  ----------------------------------------------
                                  Larry A. Ray, President

                                GUADUAS PIPELINE COMPANY, a Cayman
                                Islands exempted company limited by shares


                                By /s/ LARRY A. RAY
                                  ----------------------------------------------
                                  Larry A. Ray, President

                                (the "Subsidiaries")


SEVEN SEAS PETROLEUM INC.
FIRST AMENDMENT-NOTE PURCHASE AGREEMENT
                                     - 5 -

<PAGE>   6

                                CHESAPEAKE ENERGY CORPORATION,
                                an Oklahoma corporation


                                By /s/ TOM L. WARD
                                  ----------------------------------------------
                                  Tom L. Ward, President

                                (the "Lender")


SEVEN SEAS PETROLEUM INC.
FIRST AMENDMENT-NOTE PURCHASE AGREEMENT
                                     - 6 -


<PAGE>   7
                 Description of Changes to Governance Documents
          Under Paragraph 5.15 of the Note Purchase and Loan Agreement
               First Amendment to Note Purchase and Loan Agreement

A. Incorporation of primary negative covenants from the Agreement. - Insert the
following in each of the formation documents and any appropriate governance
documents.

1. Certain Limitations. Notwithstanding anything to the contrary that may be
contained in this Amended and Restated Certificate of Incorporation, for as long
as Seven Seas Petroleum Inc.'s (the "Parent") 12% Senior Secured Note due 2004
dated July 23, 2001, and executed by the Parent in favor of Chesapeake Energy
Corporation ("CEC") in the aggregate amount of TWENTY TWO MILLION FIVE HUNDRED
THOUSAND DOLLARS ($22,500,000.00) (the "Senior Secured Note") remains
outstanding, the Corporation will not authorize or approve any of the following
actions without the prior written consent of CEC, as Lender under that certain
Note Purchase and Loan Agreement dated July 9, 2001, as amended from time to
time:

          1.1  Mergers. Merge, consolidate or combine with any person (other
               than with or into the Parent or any other wholly-owned subsidiary
               of the Parent) or undertake any share exchange of any of the
               Corporation's capital stock.

          1.2  Sale of Assets. Except for the sale of oil, gas or other
               hydrocarbons in the ordinary course of business and the sale of
               obsolete equipment, sell, lease or otherwise dispose of any
               assets in one or a series of related transactions that represent
               five percent (5%) or more of the greater of the Corporation's
               assets or income. In addition, the Corporation will not sell,
               grant or enter into any production payment or similar arrangement
               whether volumetric or dollar denominated.

          1.3  Liquidations. Liquidate, dissolve or effect a recapitalization or
               reorganization in any form of transaction, except by merger or
               consolidation not prohibited under paragraph 1.1 of this section.

          1.4  Charter Amendments. Make any amendment to the Corporation's
               corporate governance documents including, but not limited to, an
               amendment increasing or decreasing the number of directors
               constituting the Board, increasing the authorized capital stock
               of the Corporation or changing its corporate domicile.

          1.5  Liens. Grant, create, assume or permit to continue in existence
               any lien, security interest or encumbrance on any asset of the
               Corporation other than liens for taxes not yet due and payable,
               involuntary liens for obligations not yet due or contested in
               good faith and similar encumbrances.

          1.6  Non Dividend Distributions. Make any distributions on any of the
               Corporation's capital stock or redeem, purchase or otherwise
               acquire any of the Corporation's equity securities except: (a)
               cash dividends; or (b) as expressly permitted or required to be
               permitted by the Indenture covering the Parent's $110,000,000
               12.5% Senior Notes due 2005.


                                                                 Schedule "1""
                                                               Page 1 of 2 Pages

<PAGE>   8

          1.7  Stock. Issue any additional capital stock of the Corporation.

B. Authorized Capital. - Modify all formation documents to reduce the authorized
capital stock and equity interests to the stock or interests that are
outstanding.

C. Governance Matters. - Modify any governance provisions reasonably requested
by the Lender with respect to the pledge of the stock and the exercise of the
Lender's remedies.

                                                                 Schedule "1""
                                                               Page 2 of 2 Pages
<PAGE>   9



                           Exhibit A - Promissory Note




     Deliberately omitted; incorporated by reference to Exhibit 4(A) hereof.

<PAGE>   10



                            Exhibit B - Warrant No. 1




     Deliberately omitted; incorporated by reference to Exhibit 4(B) hereof.

<PAGE>   11






                                  July 23, 2001





                            SEVEN SEAS PETROLEUM INC
                                 (as Mortgagor)


                          CHESAPEAKE ENERGY CORPORATION
                                 (as Mortgagee)



                          -----------------------------

                           LEGAL MORTGAGE OVER SHARES




SEVEN SEAS PETROLEUM INC.
LEGAL MORTGAGE OVER SHARES

<PAGE>   12


THIS DEED OF MORTGAGE ("Deed of Mortgage") is made as of July 23,2001

BETWEEN

(1)      SEVEN SEAS PETROLEUM INC., a Cayman Islands exempted company limited by
         shares, the registered office of which is at Walker House, Mary Street,
         George Town, Grand Cayman, Cayman Islands (the "Mortgagor"); and

(2)      CHESAPEAKE ENERGY CORPORATION, an Oklahoma corporation, whose principal
         place of business is at 6100 North Western Avenue, Oklahoma City,
         Oklahoma, 73118 (the "Mortgagee") as Collateral Agent under the
         Collateral Sharing Agreement (as hereinafter defined) for itself and
         United States Trust Company of New York, ("Trustee") under that certain
         Indenture dated July 23, 2001 (the "Indenture"), pursuant to which the
         Trustee is trustee for the holders of the Mortgagor's 12% Senior
         Secured Series A Notes (the "Series A Notes") and the Mortgagor's 12%
         Senior Secured Series B Notes (the "Series B Notes").

WHEREAS

(A)      Pursuant to a Note Purchase and Loan Agreement dated as of July 9, 2001
         (the "Note Purchase and Loan Agreement") the Mortgagee agreed to
         advance to the Mortgagor the sum of Twenty-two Million Five Hundred
         Thousand United States Dollars (US$22,500,000.00), evidenced by a 12%
         Senior Secured Note due 2004 in the principal amount of TWENTY-TWO
         MILLION FIVE HUNDRED THOUSAND DOLLARS ($22,500,000.00) (the "CEC Note")
         subject to the terms and conditions stated in: (a) the Note Purchase
         and Loan Agreement; (b) the CEC Note; (c) the detachable Warrants to
         purchase twelve million six hundred twelve thousand one hundred forty
         (12,612,140) shares of the Mortgagor's ordinary shares (the
         "Warrants"); (d) the Shareholder's Rights Agreement dated July 23, 2001
         between the Mortgagor and the Mortgagee (the "Shareholder's
         Agreement"); (e) the Registration Rights Agreement dated July 23, 2001
         between the Mortgagor and the Mortgagee (the "Registration Agreement");
         (f) the Security Agreement dated July 23, 2001 between the Mortgagor
         and the Mortgagee as Collateral Agent for itself and the Trustee (the
         "Security Agreement"); (g) certain other Deeds of Mortgage Over Shares
         of the subsidiaries of the Mortgagor other than the Company dated July
         23, 2001 (the "Other Deeds of Mortgage"); (h) the Collateral Sharing
         and Agency Agreement dated as of July 23, 2001 between the Mortgagee
         and the Trustee pursuant to which the Mortgagee agrees to act as
         collateral agent for itself and the Trustee (the "Collateral Sharing
         Agreement"); and (i) any and all other documents and instruments
         executed and delivered in connection with the Note Purchase and Loan
         Agreement, the Indenture and any of the other documents executed in
         connection with the Note Purchase and Loan Agreement or the Indenture.

(B)      Upon satisfaction of certain conditions set forth in the Note Purchase
         and Loan Agreement, the CEC Note, the Warrants, and the other Related
         Agreements, the CEC Note issued under the Note Purchase and Loan
         Agreement may be exchanged by the Mortgagee in part for ordinary shares
         of the Mortgagor.




SEVEN SEAS PETROLEUM INC.
LEGAL MORTGAGE OVER SHARES



<PAGE>   13

(C)      The Note Purchase and Loan Agreement was executed on the agreement that
         the Mortgagor shall enter into this mortgage over shares in the capital
         of [NAME OF SUBSIDIARY], a [Cayman Islands company, the registered
         office of which is at [__________], [George Town, Grand Cayman, Cayman
         Islands][ a company organized under the laws of Panama][an Oklahoma
         corporation].

(D)      The Mortgagor has agreed to secure the Secured Amounts (as defined
         below) by entering into this Deed of Mortgage, as well as the other
         Financing Documents (as defined below).

IT IS AGREED as follows

1.       INTERPRETATION

         1.1      Except where the context otherwise requires, words and
                  expressions defined in the Note Purchase and Loan Agreement or
                  the recitals above shall have the same meaning where used
                  herein and the further words and expressions set out below
                  shall have the following meanings;

                  ACTIVE SUBSIDIARIES means Seven Seas Petroleum USA Inc., a
                  Delaware corporation, Seven Seas Petroleum Colombia Inc., a
                  Cayman Islands company, Petrolinson SA, a Panamanian
                  corporation, and GHK Company Colombia, an Oklahoma
                  corporation.

                  COLLATERAL AGENT means the Mortgagee as collateral agent under
                  the certain Collateral Sharing Agreement;

                  COMPANY means the company specified in Schedule 1;

                  ENFORCEMENT NOTICE means an enforcement notice served by the
                  Mortgagee on the Mortgagor pursuant to the terms of this Deed
                  of Mortgage;

                  FINANCING DOCUMENTS means the Note Purchase and Loan
                  Agreement, the Indenture, the CEC Note, the Series A Notes,
                  the Series B Notes, the Security Agreement, the Other Deeds of
                  Mortgage, this Deed of Mortgage, the Related Agreements, the
                  Collateral Sharing Agreement and any and all other documents
                  and instruments executed and delivered in connection with the
                  Note Purchase and Loan Agreement or the Indenture.

                  INACTIVE SUBSIDIARIES means Seven Seas Petroleum Holdings
                  Inc., a Cayman Islands company, Seven Seas Petroleum Turkey
                  Inc., a British Colombia corporation, Seven Seas Resources
                  Australia Inc., a British Colombia corporation, Seven Seas
                  Petroleum Australia Inc., a Cayman Islands company, Seven Seas
                  Petroleum PNG Inc., a Cayman Islands company, Seven Seas
                  Petroleum Argentina, a Cayman Islands company, Seven Seas
                  Mediterranean Inc., a Cayman Islands company, Seven Seas
                  Petroleum Turkey Inc., a Cayman Islands company, and Guaduas
                  Pipeline Company, a Cayman Islands company.



SEVEN SEAS PETROLEUM INC.
LEGAL MORTGAGE OVER SHARES


                                       2
<PAGE>   14

                  INDENTURE means the Indenture for the Series A Notes and the
                  Series B Notes as referred to in paragraph (2) above.

                  MORTGAGED PROPERTY means the Original Securities and all and
                  any other shares, securities, rights, moneys and property for
                  the time being mortgaged or charged to the Mortgagee pursuant
                  to Clause 2;

                  NOTE PURCHASE AND LOAN AGREEMENT means the facility referred
                  to in recital A as amended from time to time;

                  ORIGINAL SECURITIES means the securities listed in Schedule 1
                  which are all registered in the name of the Mortgagor and
                  following execution of this Deed of Mortgage will be
                  transferred into the name of the Mortgagee or its nominee as
                  Collateral Agent;

                  OTHER DEEDS OF MORTGAGE means each Legal Mortgage Over Shares
                  between Mortgagor and Mortgagee delivered concurrently
                  herewith or hereafter delivered;

                  RELATED AGREEMENTS means the Warrants, the warrants granted to
                  the holders of the Series A Notes, the Shareholder's
                  Agreement, the Registration Agreement and any other documents
                  or instruments executed in connection with any of the
                  foregoing;

                  SECURED AMOUNTS means all and any amounts of any kind now or
                  in the future, actual or contingent, due and payable by the
                  Mortgagor to the Mortgagee under the CEC Note and to the
                  Trustee for the benefit of the holders of the Series A Notes
                  or the Series B Notes or under or in connection with this Deed
                  of Mortgage or the other Financing Documents and references to
                  the Secured Amounts include references to any part of them;
                  and

                  SECURITY INTEREST means any mortgage, charge, pledge, lien,
                  encumbrance, right of set off or any security interest,
                  howsoever created or arising.

         1.2      In this Deed of Mortgage:

                  (a)      references to the Mortgagor or the Mortgagee include
                           references to any person for the time being deriving
                           title under each of them respectively;

                  (b)      references to this Deed of Mortgage and the Financing
                           Documents are references to the same as from time to
                           time varied, supplemented or amended in any manner or
                           respect whatsoever;

                  (c)      references to the Original Securities or to the
                           Mortgaged Property include references to any property
                           included in such term;

                  (d)      "mortgage" includes a transfer or assignment by way
                           of mortgage;



SEVEN SEAS PETROLEUM INC.
LEGAL MORTGAGE OVER SHARES


                                       3
<PAGE>   15

                  (e)      Unless the context otherwise indicates, words
                           importing the singular shall include the plural and
                           vice versa, and the use of the neuter, masculine, or
                           feminine gender is for convenience only and shall be
                           deemed to mean and include the neuter, masculine or
                           feminine gender; and

                  (f)      Clause headings are for ease of reference only.

2.       COVENANT TO PAY SECURED AMOUNTS AND CHARGE

         2.1      The Mortgagor covenants with the Mortgagee for the benefit of
                  the Mortgagee and the Trustee that it shall, whether or not
                  the Mortgagor shall have received an Enforcement Notice in
                  accordance with this Deed of Mortgage or notice of demand in
                  respect of the Secured Amounts, pay and discharge any moneys
                  and liabilities in respect of the Secured Amounts whatsoever
                  which are now or at any time hereafter may be due, owing or
                  payable by the Mortgagor in any currency, actually or
                  contingently, solely and/or jointly and/or severally with
                  another or others, as principal or surety on any account
                  whatsoever pursuant to this Deed of Mortgage or the other
                  Financing Documents or as a consequence of any breach,
                  non-performance, disclaimer or repudiation by the Mortgagor of
                  any of its obligations, covenants, representations or
                  warranties under this Deed of Mortgage, the other Financing
                  Documents or otherwise.

         2.2      The Mortgagor hereby transfers absolutely by way of mortgage
                  to the Mortgagee as a continuing security for the payment and
                  discharge of the Secured Amounts, all its rights, title,
                  interest and benefit, present and future in, to and under:

                  (a)      the Original Securities; and

                  (b)      all other securities and all rights, monies
                           (including, without limitation, dividends) and
                           property whatsoever which may from time to time at
                           any time be derived from, accrued on or be offered in
                           respect of the Original Shares whether by way of
                           redemption, exchange, conversion, rights, bonus,
                           capital reorganisation or otherwise howsoever.

3.       CONTINUING AND PRIMARY SECURITY

         3.1      This Deed of Mortgage shall be a continuing security, and
                  shall be in addition to and shall not affect any continuing
                  liens or other Security Interests to which the Mortgagee is or
                  will be otherwise entitled over the Mortgaged Property, which
                  liens and other Security Interests shall remain in force
                  independently of this Deed of Mortgage.

         3.2      The Original Securities and other Mortgaged Property are
                  hereby mortgaged to the Mortgagee as primary and not as
                  collateral security.

         3.3      The Mortgagor's liability hereunder shall not be discharged or
                  impaired by:



SEVEN SEAS PETROLEUM INC.
LEGAL MORTGAGE OVER SHARES



                                       4
<PAGE>   16

                  (a)      the existence or validity of any other security taken
                           by the Mortgagee in relation to the Financing
                           Documents or any enforcement of or failure to enforce
                           or the release of any such security;

                  (b)      any amendment to or variation of the Financing
                           Documents or any security relating to the Financing
                           Documents or any assignment thereof or hereof;

                  (c)      any release of or granting of time or any other
                           indulgence to the Mortgagor or any third party;

                  (d)      any invalidity, irregularity, unenforceability,
                           imperfection or avoidance of or any defect in any
                           security granted by, or any obligations of, the
                           Mortgagor or any other person hereunder or under the
                           Financing Documents or any amendment to or variation
                           thereof or of any other document or security
                           comprised therein;

                  (e)      the insolvency, liquidation, bankruptcy or
                           dissolution (or proceedings analogous thereto) of the
                           Mortgagor, the Company or any other person or the
                           appointment of a receiver or administrative receiver
                           or administrator (whether by administration order or
                           otherwise) or trustee or similar officer of any of
                           the assets of the Mortgagor, the Company or any other
                           person or the occurrence of any circumstances
                           whatsoever affecting the Mortgagor, or any other
                           person's liability to discharge its obligations under
                           the Financing Documents;

                  (f)      any release, renewal, exchange or realisation of any
                           security or obligation provided under or by virtue of
                           this Deed of Mortgage or the other Financing
                           Documents or the provision of any further security to
                           the Mortgagee at any other time; or

                  (g)      any other act, event, neglect or omission which would
                           or might but for this clause operate to impair or
                           discharge the Mortgagor's liability hereunder.

         3.4      Any release, compromise or discharge of the obligations of the
                  Mortgagor shall be deemed to be made subject to the condition
                  that it will be void if any payment or security which the
                  Mortgagee may receive or have received is set aside or proves
                  invalid for whatever reason.

         3.5      Rights may be exercised and demands may be made under this
                  Deed of Mortgage from time to time, and the liabilities and
                  obligations of the Mortgagor and the rights and security or
                  other consideration contained in this Deed of Mortgage may be
                  exercised and enforced, irrespective of

                  (a)      whether any demands, steps or proceedings are being
                           or have been taken against the Mortgagor or any third
                           party; or



SEVEN SEAS PETROLEUM INC.
LEGAL MORTGAGE OVER SHARES


                                       5
<PAGE>   17

                  (b)      whether or in what order any security to which the
                           Mortgagee may be entitled in respect of the Secured
                           Amounts is enforced.

4.       WARRANTIES AND UNDERTAKING

         4.1      The Mortgagor represents and warrants to the Mortgagee and
                  undertakes that:

                  (a)      it is the absolute legal and beneficial owner of all
                           of the Original Securities free of all Security
                           Interests, encumbrances, trusts, equities, proxies
                           and claims whatsoever (save under this Deed of
                           Mortgage or the other Financing Documents) and that
                           all of the Original Securities are fully paid up and
                           are non-assessable;

                  (b)      except as limited by the Financing Documents,
                           Mortgagor has the full legal and unlimited right to
                           vote the Original Securities in its sole discretion;

                  (c)      the Original Securities constitute 100% of the issued
                           and outstanding equity capital of the Company and are
                           all currently registered in the name of the Mortgagor
                           (subject to the registration of the Original
                           Securities in the name of the Mortgagee as Collateral
                           Agent concurrently with the execution and delivery of
                           this Deed of Mortgage);

                  (d)      the Mortgagor and the Company are duly incorporated
                           and in good standing under the respective laws of the
                           jurisdiction in which each of them is incorporated
                           and the Mortgagor has and will at all times have the
                           necessary power to enter into and perform its
                           obligations under this Deed of Mortgage and has duly
                           authorized the execution and delivery of this Deed of
                           Mortgage;

                  (e)      the Company is an exempted company under the laws of
                           the Cayman Islands and neither this Deed of Mortgage
                           or the transfer of the Original Securities to the
                           Mortgagee is subject to any stamp or other tax under
                           the laws of the Cayman Islands and this Deed of
                           Mortgage is capable of being enforced without being
                           subject to any stamp or other tax under the laws of
                           the Cayman Islands;

                  (f)      pursuant to amendments to the articles of association
                           within 45 days after the date of this Agreement, the
                           Company will not be permitted to issue any equity
                           capital other than the Original Securities;

                  (g)      the Company has no contractual or other business
                           relationship with any Inactive Subsidiary;

                  (h)      No Inactive Subsidiary has any operations, assets or
                           liabilities, direct, indirect or contingent;


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                                       6
<PAGE>   18

                  (i)      the Mortgagor holds no rights or Security Interests
                           with respect to present or future revenues and
                           assets, tangible or intangible, relating to the
                           exploration, development, production, transportation
                           and sale of petroleum in and from the Republic of
                           Colombia, directly, by assignment, or otherwise,
                           except as a shareholder of companies whose shares are
                           pledged to Mortgagee pursuant to the Financing
                           Documents;

                  (j)      this Deed of Mortgage constitutes its legal, valid,
                           binding and enforceable obligation and is a first
                           priority security interest over the Mortgaged Shares
                           effective in accordance with its terms;

                  (k)      the execution, delivery, observance and performance
                           by the Mortgagor of this Deed of Mortgage will not
                           require the Mortgagor to obtain any licenses,
                           consents or approvals and will not result in any
                           violation to the best of the Mortgagor's knowledge,
                           of any law, statute, ordinance, rule or regulation
                           applicable to it or any other agreements;

                  (l)      the Company is not a party or otherwise bound to any
                           employment, management or other agreement, the effect
                           of which would be to limit the ability of the
                           Mortgagee to manage the Company upon an event of
                           Default under the Financing Documents or give rise to
                           any payment or penalty to terminate any such
                           arrangement;

                  (m)      it has obtained all the necessary authorizations and
                           consents to enable it to enter into this Mortgage and
                           the necessary authorizations and consents will remain
                           in full force and effect at all times during the
                           existence of the security constituted by this Deed of
                           Mortgage;

                  (n)      the execution, delivery, observance and performance
                           by the Mortgagor of the Deed of Mortgage will not
                           constitute an event of default or trigger any
                           enforcement under any Security Interest in the
                           Mortgagor's assets nor will it result in the creation
                           of any Security Interest over or in respect of the
                           present or future assets of the Company;

                  (o)      the Mortgagor has fully disclosed in writing to the
                           Mortgagee all facts relating to the Mortgagor and the
                           Company which the Mortgagor knows or should
                           reasonably know and which are material for disclosure
                           to the Mortgagee in the context of the Financing
                           Documents; and

                  (p)      no agreement to which the Mortgagor or the Company or
                           its Colombian branch is a party, or law, decree or
                           regulation to which either is subject, including
                           without limitation any agreement with Empresa
                           Colombiana de Petroleos or imposition by the Ministro
                           de Minas y Energia de Colombia or any other
                           instrumentality of the Republic of Colombia requires
                           the consent of any such person to the execution,
                           delivery or performance of this Deed of Mortgage and
                           the other Financing Documents and each obligation and
                           covenant contained herein and therein.


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                                       7
<PAGE>   19

         4.2      The Mortgagor undertakes that, for so long as any Secured
                  Amounts remain outstanding:

                  (a)      the Mortgagor shall pay to the Mortgagee, upon
                           demand, the amount of all reasonable expenses which
                           the Mortgagee may incur in, about or with a view to
                           perfecting or enforcing this security or otherwise in
                           connection with this security;

                  (b)      the Mortgagor shall promptly pay (and shall indemnify
                           the Mortgagee on demand against) all calls,
                           installments and other payments which may be made or
                           become due in respect of the Mortgaged Property and
                           so that, in the event of default by the Mortgagor,
                           the Mortgagee may do so on behalf of the Mortgagor
                           and clause 4.2(a) shall apply accordingly;

                  (c)      to the extent any Mortgaged Property is at any time
                           not vested in the Mortgagee or its nominee as
                           Collateral Agent the Mortgagor shall forthwith and
                           from time to time deposit with the Mortgagee all
                           certificates and other documents of title relating to
                           the Mortgaged Property and signed share transfer
                           forms;

                  (d)      the Mortgagor will maintain the Company as an
                           exempted company under the laws of the Cayman Islands
                           so that the transactions or enforcement actions
                           contemplated hereunder will be capable of being
                           completed without incurrence of any stamp or other
                           tax under the laws of the Cayman Islands;

                  (e)      the Mortgagor will not permit the Company to enter
                           into or become bound by any employment, management or
                           other agreement, the effect of which would be to
                           limit the ability of the Mortgagee to manage the
                           Company upon an event of Default under the Financing
                           Documents or give rise to any payment or penalty to
                           terminate any such arrangement;

                  (f)      the Mortgagor will not permit any Inactive Subsidiary
                           to conduct operations or own any asset or incur any
                           liability, direct, indirect or contingent;

                  (g)      Mortgagor will not permit the Company to engage in
                           any transaction, contractual or otherwise, with any
                           affiliate of Mortgagor except with Mortgagor and
                           Active Subsidiaries and as may otherwise be permitted
                           by the Financing Documents; provided however, that in
                           no event shall the Company engage in any transaction,
                           contractual or otherwise, with an Inactive
                           Subsidiary;

                  (h)      the Mortgagor shall deliver to the Mortgagee undated
                           letters of resignation executed by all persons now or
                           hereafter serving as Directors of the Company from
                           time to time, which letters the Mortgagee shall be
                           entitled

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                                       8
<PAGE>   20

                           to date and cause to be given immediate effect as of
                           the date of an Enforcement Notice;

                  (i)      the Mortgagor shall forthwith sign, seal, deliver and
                           complete all transfers, renunciations, proxies
                           (including irrevocable proxies if the Mortgagee so
                           requests) mandates, assignments, deeds and documents
                           and do all acts and things which the Mortgagee may,
                           in its absolute discretion, at any time and from time
                           to time specify for enabling or assisting the
                           Mortgagee:

                           (i)      to perfect or improve its title to and
                                    security over the Mortgaged Property
                                    including, without limitation, obtaining
                                    such approvals or consents to the rights and
                                    remedies granted to the Mortgagee herein as
                                    the Mortgagee requests in the Mortgagee's
                                    sole discretion;

                           (ii)     to vest the Mortgaged Property (including
                                    without limitation the registration thereof
                                    in the applicable share registry) in the
                                    Mortgagee or its nominee or nominees as
                                    Collateral Agent as of the date of execution
                                    of this Deed of Mortgage;

                           (iii)    to exercise (or enable its nominee or
                                    nominees to exercise) any rights or powers
                                    attaching to the Mortgaged Property;

                           (iv)     after the service of an Enforcement Notice
                                    to sell or dispose of the Mortgaged
                                    Property; or

                           (v)      otherwise to enforce any of the rights of
                                    the Mortgagee under or in connection with
                                    this Deed of Mortgage;

                  (j)      the Mortgagor shall not (without the written consent
                           of the Mortgagee):

                           (i)      create or permit to exist over all or part
                                    of the Mortgaged Property (or any interest
                                    therein) any Security Interest (other than
                                    created or expressly permitted to be created
                                    under this Deed of Mortgage or under other
                                    Financing Documents) whether ranking prior
                                    to, pari passu with or behind the security
                                    contained in this Deed of Mortgage;

                           (ii)     sell, transfer or otherwise dispose of the
                                    Mortgaged Property or any interest therein
                                    or attempt or agree to so dispose;

                           (iii)    permit any person other than the Mortgagee
                                    or its nominee to be registered as or become
                                    the holder of the Mortgaged Property as
                                    Collateral Agent; or

                           (iv)     vote in favour of a resolution or amend,
                                    modify or change the memorandum and articles
                                    of association of the Company or




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                                       9
<PAGE>   21


                                    authorize the issuance by the Company of any
                                    shares or any other equity security.

                           (v)      except as otherwise permitted by the
                                    Financing Documents permit the Company to
                                    transfer, assign, dispose of or encumber any
                                    rights or interests of the Company, direct
                                    or indirect, with respect to petroleum
                                    exploration, development, production,
                                    transportation, sale or other disposition or
                                    with respect to any association or other
                                    contract under which the Company has such
                                    rights or interests;

                           (vi)     permit the Company to grant any Security
                                    Interest in, or otherwise encumber, any of
                                    its assets, tangible or intangible, except
                                    as may be expressly permitted by the
                                    Financing Documents;

                           (vii)    permit the Company to make any distribution
                                    or payment to or for the benefit of
                                    Mortgagor, whether directly or otherwise, if
                                    the effect of that distribution or payment
                                    is to render the Company insolvent or unable
                                    to pay its obligations as they mature; or

                           (viii)   take any other action that would have as its
                                    effect a breach of a Financing Document.

                  (k)      to the extent received by the Mortgagor, it shall
                           forward to the Mortgagee all notices, reports,
                           accounts and other documents relating to the
                           Mortgaged Property or which are sent to the holders
                           of any of the Mortgaged Property as soon as they are
                           received;

                  (l)      no further shares or equity securities of any kind in
                           the Company (or any options or other rights with
                           respect thereto) will be issued and the authorized
                           shares shall at no time exceed the issued shares;

                  (m)      at any time after the service of an Enforcement
                           Notice, it shall exercise all voting and other rights
                           and powers which may at any time be exercisable by
                           the holder of the Mortgaged Property as the Mortgagee
                           may in its absolute discretion direct, it being
                           understood that the Mortgagee has reserved the right
                           to exercise all such voting rights directly for any
                           proper purpose, including without limitation the
                           immediate removal of Directors of the Company and
                           their replacement;

                  (n)      the Mortgagor shall not take or accept any Security
                           Interest from the Company or, in relation to the
                           Secured Amounts, from any third party, without first
                           obtaining the Mortgagee's written consent or permit
                           any Security Interest to be granted by the Company to
                           any third party, except as may be expressly permitted
                           by the Financing Documents;



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                                       10
<PAGE>   22

                  (o)      the Mortgagor shall not prove in a liquidation or
                           winding up of the Company in competition with the
                           Mortgagee for any amount whatsoever owing to the
                           Mortgagee by the Mortgagor on any account whatsoever;
                           and

                  (p)      the Mortgagor shall not claim payment whether
                           directly or by set-off, lien, counterclaim or
                           otherwise of any amount which may be or has become
                           due to the Mortgagor by the Company.

5.       POWER OF ATTORNEY

         5.1      The Mortgagor hereby irrevocably and by way of security for
                  the payment by it of the Secured Amounts and the performance
                  of its obligations under this Deed of Mortgage appoints the
                  Mortgagee as its true and lawful attorney (with full power to
                  appoint substitutes and to subdelegate) on behalf of the
                  Mortgagor and in the Mortgagor's own name or otherwise, at any
                  time and from time to time, to sign, seal, deliver and
                  complete all transfers, renunciations, proxies, mandates,
                  assignments, deeds and documents and do all acts and things
                  which the Mortgagee may, in its sole and absolute discretion,
                  consider to be necessary or advisable to perfect or improve
                  its security over the Mortgaged Property or to give proper
                  effect to the intent and purposes of this Deed of Mortgage or,
                  after delivery of an Enforcement Notice to enable or assist in
                  any way in the exercise of any power of sale of the Mortgaged
                  Property (whether arising under this Deed of Mortgage or
                  implied by statute or otherwise).

6.       ENFORCEMENT

         6.1      The Mortgagee may at any time after the occurrence of an event
                  of Default (as defined in the Note Purchase and Loan
                  Agreement) which has not been timely cured but including,
                  without limitation, the breach of any representation, warranty
                  or covenant contained in this Deed of Mortgage and the other
                  Financing Documents) serve an Enforcement Notice on the
                  Mortgagor. Unless and until the Mortgagee shall have served an
                  Enforcement Notice, but not thereafter: (a) Mortgagee agrees
                  to the fullest extent permitted by applicable law that the
                  Mortgagor has the right to receive payment of any and all cash
                  dividends distributed in respect of the Original Securities
                  and all other securities which may from time to time at any
                  time be derived from the Original Securities; and (b) appoints
                  Mortgagor as Mortgagee's agent and proxy to vote all of the
                  securities described in clause (a) above and exercise all
                  rights and privileges attributable to such securities as
                  permitted under applicable law. Prior to default, if the
                  Mortgagee shall receive any dividend or money described in
                  clause (a) above, the Mortgagee shall receive the same as
                  agent for Mortgagor and upon receipt shall promptly pay or
                  remit the same, without reduction, to Mortgagor. At the
                  request of Mortgagor, Mortgagee shall give such reasonable
                  assurances, confirmations and advice to any third party as may
                  be necessary for Mortgagor to enjoy the full benefit of the
                  rights and privileges described in clauses (a) and (b) above.



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                                       11
<PAGE>   23

         6.2      If the Mortgagee shall serve an Enforcement Notice, the
                  Mortgagee shall, without prejudice to any other right or
                  remedy available hereunder or under applicable law, forthwith
                  become entitled:

                  (a)      solely and exclusively to exercise all voting rights
                           attaching to the Mortgaged Property or any thereof
                           and shall exercise such rights in such manner as the
                           Mortgagee may in its absolute discretion determine;
                           and/or

                  (b)      solely and exclusively to exercise any and all other
                           rights and/or powers and/or discretions of the
                           Mortgagor in, to and under the Mortgaged Property
                           pursuant to the constitutional documents of the
                           Company; and/or

                  (c)      to receive and retain all dividends and other
                           distributions made on or in respect of the Mortgaged
                           Property or any thereof and any such dividends and
                           other distributions received by the Mortgagor after
                           such time shall be held in trust by the Mortgagor for
                           the Mortgagee and be paid or transferred to the
                           Mortgagee on demand; and/or

                  (d)      without notice to, or further consent or concurrence
                           by, the Mortgagor to sell the Mortgaged Property or
                           any part thereof by such method, at such place and
                           upon such terms as the Mortgagee may in its absolute
                           discretion determine, with power to postpone any such
                           sale and in any such case the Mortgagee may exercise
                           any and all rights attaching to the Mortgaged
                           Property as the Mortgagee in its discretion may
                           determine and without being answerable for any loss
                           occasioned by such sale or resulting from
                           postponement thereof or the exercise of such rights;
                           upon any sale of the Mortgaged Property or any part
                           thereof the purchaser thereof shall not be bound to
                           see or enquire whether the power of sale of the
                           Mortgagee has arisen in the manner herein provided
                           and the sale shall be deemed to be within the power
                           of the Mortgagee and the receipt of the Mortgagee for
                           the purchase money shall effectively discharge the
                           purchaser of the Mortgaged Property, or any part
                           thereof, who shall not be concerned or be in any way
                           answerable therefor; and/or

                  (e)      to appoint a receiver in respect of the Mortgaged
                           Property and the provisions of Clause 7 shall apply
                           thereto.

         6.3      The Mortgagee shall not be liable for any loss or damage
                  occasioned by any sale or disposal of the Mortgaged Property
                  (or interest therein) or arising out of the exercise of or
                  failure to exercise any of its powers under this Deed of
                  Mortgage or for any neglect or default to pay any instalment
                  or accept any offer or notify the Mortgagor of any such matter
                  or for any other loss of any nature whatsoever in connection
                  with the Mortgaged Property.


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                                       12
<PAGE>   24


7.       MORTGAGEE'S RIGHTS AS TO MORTGAGED PROPERTY

         If the Mortgagee shall serve an Enforcement Notice, the Mortgagee
         shall, without prejudice to any other right or remedy available
         hereunder or under applicable law, forthwith become entitled:

         7.1      solely and exclusively to exercise all voting rights attaching
                  to the Mortgaged Property or any thereof and shall exercise
                  such rights in such manner as the Mortgagee may in its
                  absolute discretion determine; and/or

         7.2      solely and exclusively to exercise all other rights and/or
                  powers and/or discretions of the Mortgagor in, to and under
                  the Mortgaged Property pursuant to the memorandum and articles
                  of association of the Company; and/or

         7.3      to receive and retain all dividends and other distributions
                  made on or in respect of the Mortgaged Property or any thereof
                  and any such dividends and other distributions received by the
                  Mortgagor after such time shall be held in trust by the
                  Mortgagor for the Mortgagee and be paid or transferred to the
                  Mortgagee on demand to be applied towards the discharge of the
                  Secured Obligations; and/or

         7.4      without notice to, or further consent or concurrence by, the
                  Mortgagor to sell or otherwise dispose of the Mortgaged
                  Property or any part thereof by such method, at such place and
                  upon such terms as the Mortgagee may in its absolute
                  discretion determine, with power to postpone any such sale and
                  in any such case the Mortgagee may exercise any and all rights
                  attaching to the Mortgaged Property as the Mortgagee in its
                  absolute discretion may determine and without being answerable
                  for any loss occasioned by such sale or resulting from
                  postponement thereof or the exercise of such rights; and/or

         7.5      to date and deliver the documents delivered to it pursuant to
                  this Mortgage as it considers appropriate and to take all
                  steps not already taken to register the Mortgaged Property in
                  the name of the Mortgagee or its nominee or nominees as
                  Collateral Agent and to assume control as registered owner of
                  the Mortgaged Property.

8.       OTHER SECURITY

         8.1      This security is in addition to and shall not affect or be
                  merged in any bills, notes, guarantees, indemnities,
                  undertakings, Security Interests, or other security whatsoever
                  which the Mortgagee may hold now or hereafter in connection
                  with the Financing Documents or the obligations of any other
                  person liable for any of the Secured Amounts.

9.       FURTHER PROVISIONS

         9.1      (a)      This security is in addition to, and shall neither be
                           merged in, nor in any way exclude or prejudice, any
                           other Security Interest or right of recourse


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                                       13
<PAGE>   25

                           or other right whatsoever which the Mortgagee may now
                           or at any time hereafter hold or have (or would apart
                           from this security hold or have) as regards the
                           Mortgagor or any other, person in respect of the
                           Secured Amounts.

                  (b)      The powers which this Deed of Mortgage confer on the
                           Mortgagee are cumulative, without prejudice to its
                           powers under the general law, and may be exercised as
                           often as the Mortgagee thinks appropriate; the
                           Mortgagee may, in connection with the exercise of its
                           powers, join or concur with any person in any
                           transaction, scheme or arrangement whatsoever; and
                           the Mortgagor acknowledges that the respective powers
                           of the Mortgagee shall in no circumstances whatsoever
                           be suspended, waived or otherwise prejudiced by
                           anything other than an express waiver or variation in
                           writing.

                  (c)      The rights of the Mortgagee in relation to the
                           Mortgaged Property and the recovery of the Secured
                           Amounts (whether arising under this Deed of Mortgage,
                           the other Financing Documents or under the general
                           law) shall not be capable of being waived or varied
                           otherwise than by an express waiver or variation in
                           writing; and in particular any failure to exercise or
                           any delay in exercising any of such rights shall not
                           operate as a waiver or variation of that or any other
                           such right; any defective or partial exercise of any
                           such right shall not preclude any other or further
                           exercise of that or any other such right; and no act
                           or course of conduct or negotiation on its part or on
                           its behalf shall in any way preclude it from
                           exercising any such right or constitute a suspension
                           or any variation of any such right.

                  (d)      If any of the provisions of this Deed of Mortgage
                           becomes invalid, illegal or unenforceable in any
                           respect under any law, the validity, legality and
                           enforceability of the remaining provisions shall not
                           in any way be affected or impaired.

                  (e)      In any proceedings relating to this Deed of Mortgage
                           a statement as to any amount due to the Mortgagee or
                           the Trustee under the Financing Documents which is
                           certified as being correct by an officer or agent of
                           the Mortgagee shall, save in the case of manifest
                           error, be conclusive evidence that such amount is in
                           fact due and payable.

         9.2      Assignment

                  9.2.1    This Deed of Mortgage shall be binding upon and inure
                           to the benefit of each party hereto and its
                           successors in title and permitted assigns.

                  9.2.2    The Mortgagor shall not be entitled to assign or
                           transfer any of its rights, benefits or obligations
                           hereunder without the prior written consent of the
                           Mortgagee.


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                                       14
<PAGE>   26

                  9.2.3    The Mortgagee may assign or transfer all or any part
                           of its rights, benefits or obligations under this
                           Deed of Mortgage to any other person which is its
                           successor under the Financing Documents. Where the
                           Mortgagee assigns or transfers its obligations or any
                           part thereof, the Mortgagor shall execute such
                           documents as the Mortgagee may specify to release the
                           Mortgagee to the extent of the assignment or transfer
                           or with a view to perfecting such assignment or
                           transfer, or where necessary, shall execute further
                           security documentation in favour of the assignee or
                           transferee in like form to this Deed of Mortgage.

         9.3      Release of Security

                  Upon final and unconditional repayment of the Secured Amounts
                  in full and provided that no event of Default has occurred,
                  the Mortgagee shall promptly assign the Mortgaged Property to
                  the Mortgagor free of all Security Interests, encumbrances,
                  trusts, equities and claims whatsoever imposed by the
                  Mortgagee and the Mortgagee shall forthwith sign, seal,
                  deliver and complete all transfers, renunciations, proxies,
                  mandates, assignments, deeds and documents and do all acts and
                  things which the Mortgagor may reasonably specify to vest all
                  of the Mortgaged Property in the name of the Mortgagor or its
                  nominee.

         9.4      This Deed of Mortgage is governed by, and shall be construed
                  in accordance with, the laws of the Cayman Islands.

         9.5      (a)      The parties agree that the courts of the Cayman
                           Islands are to have exclusive jurisdiction to settle
                           any disputes which may arise in connection with the
                           legal relationships established by this Deed of
                           Mortgage (including, without limitation, claims for
                           set-off or counterclaim) or otherwise arising in
                           connection with this Deed of Mortgage.


                  (b)      The parties irrevocably waive any objections on the
                           grounds of venue of forum non conveniens or any
                           similar grounds.

                  The parties irrevocably consent to service of process by mail
                  or in any other manner permitted by the relevant law.

10.      NOTICES, ENGLISH LANGUAGE

         (a)      Each notice or other communication to be given or made
                  hereunder shall be in the English language and shall, unless
                  otherwise stated be made in writing as provided below.

         Any notice or other communication or document to be made or delivered
         by one person to another pursuant to this Deed of Mortgage shall
         (unless that other person has by fifteen days' written notice to the
         other specified another address and/or fax or telex number) be made or
         delivered to that other person at the following address, fax or telex
         number:


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                                       15
<PAGE>   27

                  The Mortgagor:


                           SEVEN SEAS PETROLEUM INC.
                                    5555 San Felipe, Suite 1700
                                    Houston, Texas 77056
                                    Attention: Larry A. Ray
                                    Fax No. (713) 621-9770

                           The Mortgagee:


                           CHESAPEAKE ENERGY CORPORATION
                                    6100 North Western Avenue
                                    Oklahoma City, Oklahoma 73118
                                    Attention: M. Rowland
                                    Fax No. (405) 879-9580

                  and shall be deemed to have been made or delivered when such
                  communication or document has been dispatched and the
                  appropriate answer back received (in the case of any
                  communication made by telex) or sent by fax to the fax number
                  of the party set out herein and when receipt is confirmed by
                  facsimile or telephone (in the case of any communication by
                  fax) or (in the case of any communication made by letter) when
                  left at that address or, as the case may be, three days after
                  being deposited in the post first class postage prepaid in an
                  envelope addressed to it at that address; Provided that any
                  communication or document to be made or delivered to the
                  Mortgagee shall be effective only when received by the
                  Mortgagee.

11.      COUNTERPARTS

This Deed of Mortgage may be executed in any number of counterparts and all such
counterparts taken together shall be deemed to constitute one and the same
instrument.

IN WITNESS WHEREOF this Deed of Mortgage has been executed and delivered as a
Deed the day and year first above written.

EXECUTED AS A DEED by                             )
the duly authorised representative                )
of SEVEN SEAS PETROLEUM INC.,                     )
in the presence of:                               )

EXECUTED AS A DEED by                             )
the duly authorised representative                )
of CHESAPEAKE ENERGY CORPORATION                  )
as Collateral Agent                               )
in the presence of:                               )




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                                       16
<PAGE>   28



SCHEDULE 1

ORIGINAL SECURITIES


Company: ________________, a __________________ with its registered office at:




<Table>
<Caption>
Amount or number of
Original Securities                    Description of Original Securities
-------------------                    ----------------------------------
<S>                                   <C>
[____]                                 Shares of [        ] par value
</Table>






                                       17
<PAGE>   29
                        DEPOSIT ACCOUNT CONTROL AGREEMENT

                          SOUTHWEST BANK OF TEXAS, N.A.

THIS DEPOSIT ACCOUNT CONTROL AGREEMENT (this "Agreement") is made and entered
into as of July 23, 2001, by SEVEN SEAS PETROLEUM, INC., a Cayman Islands
exempted company limited by shares (the "Debtor"), having its principal office
at 5555 San Felipe, Suite 1700, Houston, Texas 77056, CHESAPEAKE ENERGY
CORPORATION, an Oklahoma corporation having an office at 6100 North Western,
Oklahoma City, Oklahoma 73118 ("Chesapeake"), as collateral agent for: (a)
itself as "Lender" under that certain Note Purchase and Loan Agreement dated
July 9, 2001; and (b) U.S. Trust Company of Texas, N.A. (the "Trustee") as
trustee under that certain Indenture dated July 23, 2001, between the Debtor and
the Trustee (the "Creditor") and Southwest Bank of Texas, N.A. ("Bank").

WHEREAS, Bank holds the deposit accounts set forth on schedule 1 attached hereto
for Debtor (the "Accounts"). Debtor has granted Creditor a security interest in
each of the Accounts and Creditor, Debtor and Bank are entering into this
Agreement to perfect Creditor's security interest in each of the Accounts.

                                    AGREEMENT

     In consideration of the foregoing, Bank, Debtor and Creditor agree as
follows:

         1. THE ACCOUNTS. Bank represents and warrants to Creditor that (a)
Schedule 1 is a complete and accurate statement of each of the Accounts as of
the date hereof; (b) Bank has not agreed with any party, other than Debtor and
Creditor, to comply with instructions concerning any of the Accounts; and (c)
Bank does not know of any claim to or interest in any of the Accounts, other
than the interests of Creditor and Debtor and any claim of Bank permitted under
Section 2 of this Agreement.

         2. PRIORITY OF LIEN. Bank waives any encumbrances, claims and rights of
setoff (or recoupment) it may have against any of the Accounts and agrees that,
except with respect to payment of its fees under the deposit agreement between
Debtor and Bank ("Customer Agreement"), it will not assert any banker's lien,
encumbrance, claim or setoff against any of the Accounts.

         3. CONTROL. Bank will comply with instructions, including, but not
limited to, instructions to close each of the Accounts and transmit the balances
of each of the Accounts to Creditor, given by Creditor concerning any of the
Accounts without the consent of Debtor. Neither Bank nor Debtor will agree with
any other person to comply with instructions concerning any of the Accounts
given by any person other than Debtor or Creditor.

         4. DEBTOR'S AUTHORITY TO WITHDRAW. Bank may comply with Debtor's
instructions concerning each of the Accounts until Creditor notifies Bank that
Creditor is exercising exclusive control over each of the Accounts. After
Creditor notifies Bank of Creditor's exclusive control, Bank shall stop
complying with any instructions given by the



<PAGE>   30

Debtor. Bank has no liability to Creditor for following Debtor's instructions
before Creditor notifies Bank of Creditor's exclusive control.

         5.  STATEMENTS AND CONFIRMATIONS. Bank will send copies of all
statements and other correspondence concerning each of the Accounts to Creditor
at Creditor's address at the top of this Agreement, to the attention of Marcus
C. Rowland, Executive Vice President.

         6.  RESPONSIBILITY OF BANK. Bank has no liability to Debtor for
complying with Creditor's notice of exclusive control or complying with
instructions concerning the Accounts given by Creditor. This Agreement does not
create any obligation or duty of Bank other than those expressly set forth
herein.

         7.  TAX REPORTING. All income, gain, expense and loss recognized in the
Accounts shall be reported to all taxing authorities under Debtor's name and
taxpayer identification number.

         8.  CUSTOMER AGREEMENT. The terms of this Agreement will prevail if
this Agreement conflicts with any other agreement between Bank and Debtor,
including, but not limited to, the Customer Agreement. Irrespective of any term
of the Customer Agreement, the Uniform Commercial Code of Texas shall govern the
Accounts.

         9.  TERMINATION. The obligations of Bank under this Agreement shall
continue until Creditor has notified Bank that Bank is released from further
obligation to comply with Creditor's instructions concerning the Accounts.

         10. THIS AGREEMENT. This Agreement is the entire agreement of the
parties with respect to the subject matter of this Agreement and supersedes and
discharges all prior agreements (written or oral) and negotiations and all
contemporaneous oral agreements concerning this subject matter.

         11. AMENDMENTS. No amendment, modification or termination of this
Agreement or waiver of any right shall be binding on any party unless it is in
writing and is signed by the party to be charged.

         12. SEVERABILITY. If any term of this Agreement is invalid or
unenforceable, the remainder of this Agreement shall be construed as if such
invalid or unenforceable term were omitted.

         13. SUCCESSORS. The terms of this Agreement are binding upon, and inure
to the benefit of, the parties and their respective successors or heirs and
personal representatives.

         14. NOTICES. Any notice or other communication required or permitted to
be given under this Agreement shall be in writing and deemed to have been
properly given when delivered in person, or when sent by telecopy or other
electronic means and electronic confirmation of error-free receipt is received
or 2 days after being sent by certified or registered United States mail, return
receipt requested, postage prepaid, addressed in the case of mail or electronic
transmission or delivered in the case of personal delivery to the party at the
address set

                                      -2-
<PAGE>   31

forth next to such party's name at the top of this Agreement. Any party may
change that party's address for notices in the manner set forth above.

         15. CHOICE OF LAW. This Agreement shall be governed by the internal
laws of the State of Texas.

         IN WITNESS WHEREOF, the parties hereto have executed or caused this
Agreement to be executed under seal as of the date and year first written above.

                                 SOUTHWEST BANK OF TEXAS, N.A.

                                 By
                                   ---------------------------------------------


                                 CHESAPEAKE ENERGY CORPORATION

                                 By
                                   ---------------------------------------------


                                 SEVEN SEAS PETROLEUM, INC.

                                 By
                                   ---------------------------------------------


                                      -3-
<PAGE>   32



                                  SCHEDULE "1"

<Table>
<S>                                             <C>
                 1. DEPOSIT ACCOUNT NO.         9159611
                 2. DEPOSIT ACCOUNT NO.         159611
                 3. DEPOSIT ACCOUNT NO.         172391
                 4. DEPOSIT ACCOUNT NO.         323241
                 5. DEPOSIT ACCOUNT NO.         323349
                 6. DEPOSIT ACCOUNT NO.         323276
                 7. DEPOSIT ACCOUNT NO.         323462
</Table>




                                       -4-

<PAGE>   33


                        DEPOSIT ACCOUNT CONTROL AGREEMENT

                              FIDELITY INVESTMENTS

         THIS DEPOSIT ACCOUNT CONTROL AGREEMENT (this "Agreement") is made and
entered into as of July 23, 2001, by SEVEN SEAS PETROLEUM, INC., a Cayman
Islands exempted company limited by shares (the "Debtor"), having its principal
office at 5555 San Felipe, Suite 1700, Houston, Texas 77056, CHESAPEAKE ENERGY
CORPORATION, an Oklahoma corporation having an office at 6100 North Western,
Oklahoma City, Oklahoma 73118 ("Chesapeake"), as collateral agent for: (a)
itself as "Lender" under that certain Note Purchase and Loan Agreement dated
July 9, 2001; and (b) U.S. Trust Company of Texas, N.A. (the "Trustee") as
trustee under that certain Indenture dated July 23, 2001, between the Debtor and
the Trustee (the "Creditor") and Fidelity Investments ("Fidelity").

         WHEREAS, Fidelity holds Deposit Account No. 503276347 for Debtor (the
"Account"). Debtor has granted Creditor a security interest in the Account and
Creditor, Debtor and Fidelity are entering into this Agreement to perfect
Creditor's security interest in the account.

                                    AGREEMENT

         In consideration of the foregoing, Fidelity, Debtor and Creditor agree
as follows:

         1. THE ACCOUNT. Fidelity represents and warrants to Creditor that (a)
Schedule 1 is a complete and accurate statement of the Account as of the date
hereof, (b) Fidelity has not agreed with any party, other than Debtor and
Creditor, to comply with instructions concerning the Account and Fidelity does
not know of any claim to or interest in the Account, other than the interests of
Creditor and Debtor and any claim of Fidelity permitted under Section 2.

         2. PRIORITY OF LIEN. Fidelity waives any encumbrances, claims and
rights of setoff (or recoupment) it may have against the Account and agrees
that, except with respect to payment of its fees under the deposit agreement
between Debtor and Fidelity ("Customer Agreement"), it will not assert any
banker's lien, encumbrance, claim or setoff against the Account.

         3. CONTROL. Fidelity will comply with instructions, including, but not
limited to, instructions to close the Account and transmit the Account balance
to Creditor, given by Creditor concerning the Account without the consent of
Debtor. Neither Fidelity nor Debtor will agree with any other person to comply
with instructions concerning the Account given by any person other than Debtor
or Creditor.

         4. DEBTOR'S AUTHORITY TO WITHDRAW. Fidelity may comply with Debtor's
instructions concerning the Account until Creditor notifies Fidelity that
Creditor is exercising exclusive control over the Account. After Creditor
notifies Fidelity of Creditor's exclusive control, Fidelity shall stop complying
with any instructions given by the Debtor. Fidelity has no liability to Creditor
for following Debtor's instructions before Creditor notifies Fidelity of
Creditor's exclusive control.




<PAGE>   34

         5.  STATEMENTS AND CONFIRMATIONS. Fidelity will send copies of all
statements and other correspondence concerning the Account to Creditor at
Creditor's address at the top of this Agreement, to the attention of Marcus C.
Rowland, Executive Vice President.

         6.  RESPONSIBILITY OF FIDELITY. Fidelity has no liability to Debtor for
complying with Creditor's notice of exclusive control or complying with
instructions concerning the Account given by Creditor. This Agreement does not
create any obligation or duty of Fidelity other than those expressly set forth
herein.

         7.  TAX REPORTING. All income, gain, expense and loss recognized in the
Account shall be reported to all taxing authorities under Debtor's name and
taxpayer identification number.

         8.  CUSTOMER AGREEMENT. The terms of this Agreement will prevail if
this Agreement conflicts with any other agreement between Fidelity and Debtor,
including, but not limited to, the Customer Agreement. Irrespective of any term
of the Customer Agreement, the Uniform Commercial Code of Texas shall govern the
Account.

         9.  TERMINATION. The obligations of Fidelity under this Agreement shall
continue until Creditor has notified Fidelity that Fidelity is released from
further obligation to comply with Creditor's instructions concerning the
Account.

         10. THIS AGREEMENT. This Agreement is the entire agreement of the
parties with respect to the subject matter of this Agreement and supersedes and
discharges all prior agreements (written or oral) and negotiations and all
contemporaneous oral agreements concerning this subject matter.

         11. AMENDMENTS. No amendment, modification or termination of this
Agreement or waiver of any right shall be binding on any party unless it is in
writing and is signed by the party to be charged.

         12. SEVERABILITY. If any term of this Agreement is invalid or
unenforceable, the remainder of this Agreement shall be construed as if such
invalid or unenforceable term were omitted.

         13. SUCCESSORS. The terms of this Agreement are binding upon, and inure
to the benefit of, the parties and their respective successors or heirs and
personal representatives.

         14. NOTICES. Any notice or other communication required or permitted to
be given under this Agreement shall be in writing and deemed to have been
properly given when delivered in person, or when sent by telecopy or other
electronic means and electronic confirmation of error-free receipt is received
or 2 days after being sent by certified or registered United States mail, return
receipt requested, postage prepaid, addressed in the case of mail or electronic
transmission or delivered in the case of personal delivery to the party at the
address set forth next to such party's name at the top of this Agreement. Any
party may change that party's address for notices in the manner set forth above.

                                       -2-
<PAGE>   35

         15. CHOICE OF LAW. This Agreement shall be governed by the internal
laws of the State of Texas.

                  IN WITNESS WHEREOF, the parties hereto have executed or caused
this Agreement to be executed under seal as of the date and year first written
above.

                                FIDELITY INVESTMENTS


                                By
                                  ----------------------------------------------



                                CHESAPEAKE ENERGY CORPORATION


                                By
                                  ----------------------------------------------



                                SEVEN SEAS PETROLEUM, INC.


                                By
                                  ----------------------------------------------





                                      -3-
<PAGE>   36



                 Escrow Agreement - Existing Indenture Interest




    Deliberately omitted; incorporated by reference to Exhibit 10(G) hereof.

<PAGE>   37



                     Escrow Agreement - Sub-Thrust Test Well




     Deliberately omitted; incorporated by reference to Exhibit 10(H) hereof.

<PAGE>   38



                               Security Agreement




    Deliberately omitted; incorporated by reference to Exhibit 10(C) hereof.

<PAGE>   39



                    Exhibit E - Registration Rights Agreement




     Deliberately omitted; incorporated by reference to Exhibit 4(D) hereof.






<PAGE>   40
                     COLLATERAL SHARING AND AGENCY AGREEMENT

         THIS COLLATERAL SHARING AND AGENCY AGREEMENT (this "Agreement") is made
effective the 23rd day of July, 2001, among CHESAPEAKE ENERGY CORPORATION, an
Oklahoma corporation ("Chesapeake"), U.S. TRUST COMPANY OF TEXAS, N.A., as
trustee under that certain Indenture dated as of July 23, 2001 (the "Trustee"
and collectively with Chesapeake, the "Lenders"), and CHESAPEAKE ENERGY
CORPORATION, an Oklahoma corporation in its capacity as collateral agent under
this Agreement (the "Collateral Agent").

                                   WITNESSETH:

         WHEREAS, Chesapeake and Seven Seas Petroleum Inc., a Cayman Islands
exempted company limited by shares (the "Company"), have entered into that
certain Note Purchase and Loan Agreement dated July 9, 2001 (the "Loan
Agreement"), pursuant to which Chesapeake purchased from the Company a 12%
Senior Secured Note due 2004 in the principal amount of TWENTY-TWO MILLION FIVE
HUNDRED THOUSAND DOLLARS ($22,500,000.00) (the "Chesapeake Note"); and

         WHEREAS, the Trustee and the Company have entered into that certain
Indenture dated July 23, 2001 (the "Indenture"), pursuant to which the Trustee
is trustee for the holders of the Company's 12% Senior Secured Series B Notes
which will be paid with the proceeds from and/or exchanged for the Company's 12%
Senior Secured Series A Notes in the aggregate principal amount of TWENTY-TWO
MILLION FIVE HUNDRED THOUSAND DOLLARS ($22,500,000.00) (the "Senior Notes" and,
together with the Chesapeake Note, the "Notes"); and

         WHEREAS, Chesapeake and the Company have entered into those certain
collateral security agreements described on Schedule "1" attached hereto and
made a part hereof (the "Collateral Agreements"), pursuant to which the Company
has pledged to Chesapeake, as collateral agent, the collateral described in
Schedule "2" attached hereto and made a part hereof (the "Collateral") and
granted Chesapeake, as collateral agent, a first priority security interest in
the Collateral;

         NOW, THEREFORE, in consideration of the mutual agreements herein
contained, the parties agree as follows:

1. Referenced Agreement. This Agreement is the "Collateral Sharing Agreement"
referred to in any of the Collateral Agreements. Although all parties to the
Collateral Agreements have notice of the terms and provisions of this Agreement,
none of such parties (other than the Lenders), or any other entity or person,
shall have any rights, as third party beneficiary or otherwise, by, through or
under this Agreement and no agreement, statement or provision of this Agreement
shall be used by any person or entity, except the Lenders, for any purpose
whatsoever.

2. Governing Agreement. Anything in the Collateral Agreements or the Notes to
the contrary notwithstanding, the rights of the Lenders, as such rights affect
the Lenders inter se, in connection with the Collateral and under the Collateral
Agreements and the Notes are subject to this Agreement.


COLLATERAL SHARING AND AGENCY AGREEMENT
SEVEN SEAS PETROLEUM INC.

<PAGE>   41

3. Appointment of Collateral Agent. Each of the Lenders hereby irrevocably
designates and appoints Chesapeake as such Lender's Collateral Agent and each
Lender irrevocably authorizes the Collateral Agent, in such capacity, to take
such action on its behalf under the provisions of this Agreement and the
Collateral Agreements and to exercise such powers and perform such duties as are
expressly delegated to the Collateral Agent by the terms of this Agreement and
the Collateral Agreements, together with such other powers as are reasonably
incidental thereto. Chesapeake agrees to act as Collateral Agent for the Lenders
to the extent provided under the Collateral Agreements, all on the terms and
conditions set forth in this Agreement. In its capacity as Collateral Agent,
Chesapeake is herein and in the Collateral Agreements sometimes called the
"Collateral Agent." Notwithstanding any provision to the contrary elsewhere in
this Agreement or in the Collateral Agreements, the Collateral Agent will have
no duties or responsibilities, except those expressly set forth herein, will
have no fiduciary relationship with any Lender, and no implied covenants,
functions, responsibilities, duties, obligations or liabilities will be read
into this Agreement or any of the Collateral Agreements or otherwise exist
against the Collateral Agent. The Collateral Agent may resign upon thirty (30)
days' written notice to the Lenders and in such event the Lenders shall promptly
appoint a successor Collateral Agent mutually acceptable to Chesapeake and the
Trustee.

4. Undertaking of Collateral Agent. The Collateral Agent, by itself or through
any nominee or designee party to any Collateral Agreement or through other
agents appointed to act on behalf of the Collateral Agent, as the case may be,
is hereby authorized and hereby undertakes to take all actions and exercise all
powers specifically delegated to the Collateral Agent by the terms hereof and of
the Collateral Agreements, together with all such powers as shall be reasonably
incidental thereto, and to hold the Collateral pro rata for the benefit of the
Lenders in accordance with their respective Specified Percentage. As used in
this Agreement: (a) "Indebtedness" means the principal balance of each of the
Notes plus interest, fees, expenses and any Additional Amounts (as defined in
the Indenture or the Chesapeake Note) in connection with the Notes, the Loan
Agreement, the Indenture, the Collateral Agreements and the other documents
executed in connection therewith (collectively, the "Debt Documents") and any
and all additional obligations of the Company to the Lenders arising under or
pursuant to the Debt Documents; and (b) "Specified Percentage" means as of the
date of any determination thereof, the amount of such Lender's Indebtedness
divided by the aggregate Indebtedness owing to both Lenders.

5. Capacity of Collateral Agent. The relationship between the Collateral Agent
and the Lenders is and shall be that of principal and agent only, and nothing
herein shall be construed to constitute the Collateral Agent a trustee for a
holder of any of the Indebtedness or of a participation therein, nor to impose
on the Collateral Agent duties and obligations other than those expressly
provided for herein and in the Collateral Agreements or as the Lenders shall
otherwise jointly direct. Each Lender, their respective successors and assigns
and each subsequent holder of any of the Indebtedness by its acceptance thereof,
agrees that the Collateral Agent and any nominee, designee, trustee or agent
acting for the Collateral Agent will be indemnified (to the extent not
reimbursed by the Company) with the first proceeds from the Collateral from and
against any and all losses, claims, damages, liabilities, and expenses which may
be imposed on, incurred by, or asserted against the Collateral Agent, or any
such nominee, designee, trustee or agent, in any way related to or arising out
of its status as Collateral Agent under this Agreement or any of the Collateral
Agreements or in any way related to or arising out of any such nominee,
designee, trustee or agent so acting for the Collateral Agent, except any such
losses, claims, damages, liabilities, or expenses resulting from the


COLLATERAL SHARING AND AGENCY AGREEMENT
SEVEN SEAS PETROLEUM INC.
                                      - 2 -

<PAGE>   42

gross negligence or willful misconduct of the Collateral Agent or any such
nominee, designee, trustee or agent.

6. Reliance by Collateral Agent. The Collateral Agent will be entitled to rely,
and will be fully protected in relying, upon any instrument, writing,
resolution, notice, consent, certificate, affidavit, letter, telecopy, telex or
teletype message, statement, order or other document or conversation believed by
the Collateral Agent to be genuine and correct and to have been signed, sent or
made by the proper person or persons and upon advice and statements of legal
counsel (including counsel to the Company), independent accountants and other
experts selected by the Collateral Agent. The Collateral Agent will be fully
justified in failing or refusing to take any action under this Agreement or any
of the Debt Documents unless it shall first receive such advice or concurrence
of the Lenders as it deems appropriate or it shall first be indemnified to its
satisfaction by the Lenders against any and all liability and expense that may
be incurred by the Collateral Agent by reason of taking or continuing to take
any such action.

7. Non-reliance on Collateral Agent. Each Lender expressly acknowledges that
neither the Collateral Agent nor any of its respective officers, directors,
employees, agents, attorneys-in-fact or affiliates have made any representations
or warranties to such Lender and that no act by the Collateral Agent hereafter
taken, including any review of the affairs of the Company or any affiliate shall
be deemed to constitute any representation or warranty by the Collateral Agent
to any Lender. Each Lender represents to the Collateral Agent that it has not
relied on the Collateral Agent or any other Lender in making its decision to
enter into this Agreement and the Debt Documents to which it is a party. The
Collateral Agent will not have any duty or responsibility to provide any Lender
with any credit or other information concerning the business, operations,
property, condition (financial or otherwise), prospects or creditworthiness of
the Company or any affiliate of the Company that may come into the possession of
the Collateral Agent or any of its officers, directors, employees, agents,
attorneys-in-fact or affiliates.

8. Collateral Agent's Individual Capacity. The Collateral Agent and its
affiliates may make loans to and generally engage in any kind of business with
the Company and its affiliates as though the Collateral Agent were not an agent
hereunder. The Collateral Agent will have the same rights and powers under this
Agreement and the Debt Documents to which it is a party as any Lender and may
exercise the same as though it were not the Collateral Agent, and the terms
"Lender" and "Lenders" shall include the Collateral Agent in its individual
capacity.

9. Proceeds of Collateral. Any proceeds of the Collateral obtained by the
Collateral Agent from time to time shall be distributed by the Collateral Agent
to the Lenders in accordance with their respective Specified Percentage for
application pursuant to the Collateral Agreements. Any expenses incurred by the
Collateral Agent, or by any of its nominees, designees, trustees or agents,
including, without limitation, reasonable attorneys' fees and legal expenses, in
connection with its enforcement of or foreclosure under the Collateral
Agreements, or any of them, shall (to the extent not otherwise paid by the
Company) be borne pro rata by the Lenders on the basis of their respective
Specified Percentage.

10. Care of Collateral. The Collateral Agent shall exercise the same degree of
care in handling the Collateral as the Collateral Agent would exercise in
handling similar transactions wholly for the Collateral Agent's own account.
Neither the Collateral Agent, the Lenders nor any director, officer, employee,
nominee, designee, trustee or agent of either the Collateral Agent or the
Lenders (the


COLLATERAL SHARING AND AGENCY AGREEMENT
SEVEN SEAS PETROLEUM INC.
                                      - 3 -

<PAGE>   43

"Lender Parties"), however, will be liable for action taken or omitted by any of
them hereunder or under the Collateral Agreements in connection with the
administration, enforcement and collection of the Notes or the Collateral
Agreements and the rights and remedies of the Collateral Agent and the Lenders
thereunder, except for their own willful misconduct or gross negligence. In
addition, none of the Lender Parties will be responsible for: (a) any recitals,
warranties or representations in the Collateral Agreements; (b) the execution,
genuineness, validity, effectiveness or enforceability of the Collateral
Agreements or the Collateral; or (c) any action taken or omitted pursuant to any
communication or document which they believe in good faith to be genuine or to
have been presented by a proper person. Each of the Lender Parties will be
entitled conclusively, without liability therefor, to rely upon advice of
counsel concerning legal matters. The Collateral Agent will not be under any
obligation to any Lender to ascertain or to inquire as to the observance or
performance of any of the agreements contained in, or conditions of, this
Agreement or any of the Debt Documents, or to inspect the properties, books or
records of the Company.

11. Defaults; Realization of Collateral. Upon the occurrence of an event of
Default under the Loan Agreement or the Indenture which is not cured or waived
in accordance with the terms thereof, the Collateral Agent will forthwith take
such steps as it may deem appropriate or useful to realize upon the Collateral.

12. Further Assurances. Each Lender agrees to do such further acts and things
and to execute and deliver such additional agreements, powers and instruments,
as the Collateral Agent may reasonably request to carry into effect the terms,
provisions and purposes of this Agreement, or to better assure and confirm unto
the Collateral Agent its respective rights, powers and remedies hereunder, or to
facilitate the realization of the Collateral by the Collateral Agent.

13. Notices of Default. If any Lender at any time shall acquire actual knowledge
of any default under the Loan Agreement, the Indenture or any of the Collateral
Agreements, such Lender will promptly give notice thereof to the other Lender.

14. Amendment and Termination. This Agreement may be amended or terminated by
the Lenders, acting together, at any time (without the consent of the Company or
any other person) but will otherwise remain in full force and effect until the
payment in full of the Notes or the other termination of the Collateral
Agreements.

15. Payments. Each of the Lenders agree that the Lenders will share all payments
received from realization on any of the Collateral with each other Lender in
accordance with each Lender's Specified Percentage at the time of receipt of
such payments.

16. Notices. Any notice, demand or communication required or permitted to be
given by any provision of this Agreement will be in writing and will be deemed
to have been given and received when delivered personally or by telefacsimile to
the party designated to receive such notice, or on the date following the day
sent by overnight courier, or on the third (3rd) business day after the same is
sent by certified mail, postage and charges prepaid, directed to the addresses
of the parties set forth on the signature pages hereto or to such other or
additional addresses as any party might designate by written notice to the other
parties.


17. Governing Law; Severability. This Agreement will be governed by and
construed in


COLLATERAL SHARING AND AGENCY AGREEMENT
SEVEN SEAS PETROLEUM INC.
                                      - 4 -

<PAGE>   44

accordance with the internal laws of the State of Oklahoma. If any provision of
this Agreement is prohibited by or invalid under applicable law, such provision
shall be ineffective to the extent of such prohibition or invalidity, without
invalidating the remainder of such provision or the remaining provisions of this
Agreement.

18. Successors and Assigns. This Agreement will be binding upon and will inure
to the benefit of the all permitted successors and assigns of the parties.

         IN WITNESS WHEREOF, this Agreement has been duly executed as of the day
and year first above written.

                                   CHESAPEAKE ENERGY CORPORATION,
                                   an Oklahoma corporation


                                   By
                                     ----------------------------------------
                                   Name:  Jennifer M. Grigsby
                                          -----------------------------------
                                   Title:  Corporate Secretary
                                           ----------------------------------

                                   (the "Collateral Agent and a "Lender")

                                   Notice Addresses:

                                   Chesapeake Energy Corporation
                                   Attention: Marcus C. Rowland
                                   6100 North Western
                                   Oklahoma City, Oklahoma  73118
                                   Telefacsimile: (405) 879-9580

                                   and

                                   Commercial Law Group, P.C.
                                   Attention: Ray Lees
                                   2725 Oklahoma Tower
                                   210 Park Avenue
                                   Oklahoma City, Oklahoma  73102
                                   Telefacsimile:  (405) 232-5553


COLLATERAL SHARING AND AGENCY AGREEMENT
SEVEN SEAS PETROLEUM INC.
                                      - 5 -

<PAGE>   45

                                   U.S. TRUST COMPANY OF TEXAS, N.A.


                                   By
                                     ----------------------------------------
                                   Name
                                       --------------------------------------
                                   Title
                                        -------------------------------------

                                   (the "Trustee" and a "Lender")


                                   Notice Address:

                                   U.S. Trust Company of Texas, N.A.
                                   Attention: Corporate Trust Division
                                   2001 Ross Avenue, Suite 2700
                                   Dallas, Texas 75201
                                   Telefacsimile: (214) 754-1303


COLLATERAL SHARING AND AGENCY AGREEMENT
SEVEN SEAS PETROLEUM INC.
                                      - 6 -

<PAGE>   46

                                  SCHEDULE "1"
                              COLLATERAL AGREEMENTS


1.       Security Agreement dated effective July 23, 2001 between the Company
         and the Collateral Agent.

2.       Deposit Account Control Agreement dated effective July 23, 2001 among
         the Company, the Collateral Agent and Southwest Bank of Texas, N.A.

3.       Deposit Account Control Agreement dated effective July 23, 2001 among
         the Company, the Collateral Agent and Fidelity Investments.

4.       Escrow Agreement (Existing Indenture Interest) dated effective July 23,
         2001 among the Company, the Collateral Agent and Southwest Bank of
         Texas, N.A.

5.       Escrow Agreement (Sub-Thrust Test Well) dated effective July 23, 2001
         among the Company, the Collateral Agent and Southwest Bank of Texas,
         N.A.

6.       Legal Mortgages Over Shares dated effective July 23, 2001 between the
         Company and the Collateral Agent.


COLLATERAL SHARING AND AGENCY AGREEMENT
SEVEN SEAS PETROLEUM INC.
                                      - 7 -

<PAGE>   47

                                  SCHEDULE "2"
                                   COLLATERAL


1.       All of the issued and outstanding shares of capital stock and all
         proceeds, products, additions to, replacements of, substitutions for
         and accessions with respect thereto of:

                  1.1      Seven Seas Petroleum Holdings Inc. (CI)
                  1.2      Seven Seas Petroleum Turkey Inc. (BC)
                  1.3      Seven Seas Resources Australia Inc. (BC)
                  1.4      Seven Seas Petroleum USA Inc. (DA)
                  1.5      Seven Seas Petroleum Australia Inc. (CI)
                  1.6      Seven Seas Petroleum PNG Inc. (CI)
                  1.7      Seven Seas Petroleum Argentina  Inc. (CI)
                  1.8      Seven Seas Petroleum Mediterranean  Inc. (CI)
                  1.9      Seven Seas Petroleum Turkey  Inc. (CI)
                  1.10     Seven Seas Petroleum Colombia  Inc. (CI)
                  1.11     Petrolinson SA (Pan)
                  1.12     GHK Company Colombia (OK)
                  1.13     Guaduas Pipeline Company (CI)

2.       The following collateral covered pursuant to the Security Agreement:

                  2.1      All of the Company's Accounts of any kind whether now
                           existing or hereafter arising; all Escrow and Deposit
                           Accounts; all chattel papers, documents and
                           instruments relating to the Accounts and the Escrow
                           and Deposit Accounts; and all rights now or hereafter
                           existing in and to all security agreements, leases,
                           and other contracts securing or otherwise relating to
                           any Accounts, Escrow and Deposit Accounts or any such
                           chattel papers, documents and instruments;

                  2.2      All of the Company's Equipment in all of its forms,
                           whether now owned or hereafter acquired and wherever
                           located; all parts thereof and all accessions or
                           additions thereto, whether now owned or hereafter
                           acquired;

                  2.3      All of the Company's general intangibles of any kind
                           whether now existing or hereafter arising (herein
                           called the "General Intangibles"); all chattel
                           papers, documents and instruments relating to the
                           General Intangibles; and all rights now or hereafter
                           existing in and to all security agreements, leases,
                           licenses, permits, patents, trademarks, copyrights,
                           distribution agreements and contracts securing or
                           otherwise relating to any General Intangibles or any
                           such chattel papers, documents and instruments and
                           all of the Company's lien rights against other
                           persons whether statutory, contractual or by common
                           law;

                  2.4      All of the Company's Inventory in all of its forms,
                           whether now owned or


COLLATERAL SHARING AND AGENCY AGREEMENT
SEVEN SEAS PETROLEUM INC.
                                      - 8 -

<PAGE>   48


                           hereafter acquired and wherever located, and all
                           accessions or additions thereto and products thereof,
                           whether now owned or hereafter acquired;

                  2.5      Without in any way limiting or modifying the
                           foregoing in any respect, all of the Company's goods,
                           chattels, business records, contracts, contract
                           rights, advertising agreements, tax refunds,
                           documents of title, fixtures, insurance policies and
                           proceeds, patents, trademarks, service marks, logos,
                           trade names, copyrights and applications therefor,
                           licenses, licensing fees, permits, approvals,
                           consents, certificates, stock, surveys, engineering
                           reports, tools, landscaping, machinery, furniture,
                           furnishings, business machines, appliances, vehicles,
                           trailers, rolling stock, deposits, security deposits,
                           money, securities, claims, demands, causes of action,
                           refunds, rebates, income and all other tangible and
                           intangible real, personal or mixed property whether
                           now owned or hereafter acquired;

                  2.6      Any additional properties or assets from time to time
                           delivered to or deposited with the Collateral Agent
                           as security for the Secured Indebtedness or otherwise
                           pursuant to the terms of this Agreement; and

                  2.7      All proceeds, products, additions to, replacements
                           of, substitutions for and accessions of any and all
                           of the items described in subparagraphs 2.1, 2.2,
                           2.3, 2.4, 2.5 and 2.6 hereof.


COLLATERAL SHARING AND AGENCY AGREEMENT
SEVEN SEAS PETROLEUM INC.
                                      - 9 -

<PAGE>   49


                             LOAN PURCHASE AGREEMENT

                  THIS AGREEMENT is entered into effective July 23, 2001, among
CHESAPEAKE ENERGY CORPORATION, an Oklahoma corporation ("Chesapeake"), ROBERT A.
HEFNER III, an individual ("Hefner"), and RAMIIILAJ, A LIMITED PARTNERSHIP, an
Oklahoma limited partnership ("Ramiiilaj").

                                   BACKGROUND

                  WHEREAS, Chesapeake, Seven Seas Petroleum Inc., a Cayman
Islands exempted company limited by shares (the "Borrower") and all of the
subsidiaries of the Borrower entered into that certain Note Purchase Agreement
and Loan Agreement (the "Loan Agreement") which provides for the extension of
credit (the "CEC Loan") by Chesapeake to the Borrower in the amount of
Twenty-Two Million Five Hundred Thousand Dollars ($22,500,000.00) as evidenced
by that certain promissory note of even date herewith (the "Note") and the
related issuance of warrants (the "Warrants") to purchase up to Twelve Million
Six Hundred Twelve Thousand One Hundred Forty (12,612,140) of the Borrower's
ordinary shares, representing twenty percent (20%) of the outstanding ordinary
shares of the Borrower on a fully diluted basis;

                  WHEREAS, Hefner and Ramiiilaj (jointly and severally, the
"Hefner Parties") are affiliates of the Borrower and under the terms of the Loan
Agreement agreed with others to purchase the Borrower's 12% Series B Senior
Secured Notes (the "Series B Notes") in the amount of Twenty-Two Million Five
Hundred Thousand Dollars ($22,500,000.00) as a condition to Chesapeake's
obligation to extend the Loan;

                  WHEREAS, under the terms of the Loan Agreement, the Borrower
was required to offer (the "Rights Offering") to the Borrower's stockholders the
right to purchase an approximate pro rata share of the Corporation's Series A
Senior Secured Notes due 2004 in the aggregate principal amount of Twenty-Two
Million Five Hundred Thousand Dollars ($22,500,000.00) (the "Series A Notes")
coupled with detachable warrants to purchase the Borrower's ordinary shares all
on terms substantially similar to the terms of the Loan Agreement with the
proceeds to be used to redeem all of the Series B Notes;

                  WHEREAS, to the extent that the Series A Notes are not fully
subscribed for in the Rights Offering, the holders of the Series B Notes are
required to exchange all of such parties' Series B Notes for Series A Notes and
the related warrants; and

                  WHEREAS, in order to induce Chesapeake to enter into and
perform the Loan Agreement the Hefner Parties agreed at Chesapeake's request as
provided herein to purchase a portion of the CEC Loan (together with a pro rata
portion of the Warrants) to the extent necessary to cause the principal amount
of the Series A Notes and the CEC Loan held by the Hefner Parties to equal up to
a minimum amount of Ten Million Dollars ($10,000,000.00).

                  NOW THEREFORE, in consideration of the premises and the mutual
covenants herein contained and other good and valuable consideration, the
receipt and sufficiency of which are hereby acknowledged, the parties agree as
follows:



SEVEN SEAS PETROLEUM INC.                                           Exhibit "G"
LOAN PURCHASE AGREEMENT                                       Page 1 of 6 Pages

<PAGE>   50



1. Purchase Agreement. Subject to the terms and conditions of this Agreement and
in consideration of Chesapeake entering into and performing the terms of the
Loan Agreement, the Hefner Parties hereby unconditionally and irrevocably agree
to purchase from Chesapeake a portion of the unpaid principal balance of the CEC
Loan (the "Purchased Portion") equal to the lesser of: (a) the principal portion
of the CEC Loan requested by Chesapeake to be purchased by the Hefner Parties as
provided in this Agreement; or (b) Ten Million Dollars ($10,000,000.00) reduced
by the principal amount of the Series A Notes held by the Hefner Parties. In
addition to the Purchased Portion of the CEC Loan to be purchased by the Hefner
Parties pursuant to the foregoing sentence, the Hefner Parties will purchase all
accrued and unpaid interest attributable to the Purchased Portion as of the
Closing Date (as hereinafter defined). In addition, to the extent that the
Hefner Parties actually purchase any portion of the CEC Loan under this
Agreement, Chesapeake agrees that simultaneously with such purchase Chesapeake
will convey to the Hefner Parties a portion of the Warrants equal to the
Purchased Portion divided by Twenty-Two Million Five Hundred Thousand Dollars
($22,500,000.00), rounded to the nearest whole Warrant.

2. Purchase Price. The purchase price of the Purchased Portion of the CEC Loan
will be the amount equal to the Purchased Portion, plus any accrued and unpaid
interest on the Purchased Portion plus any unpaid sums expended by Chesapeake in
connection with the CEC Loan (the "Purchase Price"). The Purchase Price will be
paid by the Hefner Parties in immediately available United States Dollars on the
day of closing of the purchase of the Purchased Portion.

3. Sale Procedure. Notice of the exercise by Chesapeake of its rights hereunder
to sell the Purchased Portion to the Hefner Parties and the consummation of such
sale will be performed as follows:

         3.1      Notices. On consummation of the purchase of the Series A Notes
                  by the Hefner Parties in the Rights Offering, the Hefner
                  Parties shall notify Chesapeake (the "Offer Notice") as to the
                  completion of the Rights Offering and the principal amount of
                  the Series A Notes purchased by the Hefner Parties for their
                  own account (excluding any Series A Notes held as agent for
                  any other parties). Chesapeake shall have fifteen (15) days
                  after receipt of the Offer Notice (the "Option Period") to
                  elect to require the Hefner Parties to purchase a portion of
                  the CEC Loan as above provided. Chesapeake election shall be
                  made by giving written notice (the "Election Notice") to the
                  Hefner Parties within the Option Period. The Election Notice
                  shall specify (i) the amount of the Purchased Portion and (ii)
                  a date for the Closing (hereafter defined), which shall not be
                  sooner than two (2) days nor later than five (5) days after
                  the Election Notice is given.

         3.2      Closing. The consummation of the purchase and sale of the
                  Purchased Portion and the portion of the Warrants to the
                  Hefner Parties (the "Closing") will be held at the offices of
                  Commercial Law Group, P.C., 210 Park Avenue, Suite 2725,
                  Oklahoma City, Oklahoma, at 10:00 A.M. on the date specified
                  by Chesapeake in the Election Notice (the "Closing Date").

         3.3      Deliveries. At the Closing, Chesapeake will deliver to the
                  Hefner Parties: (1) a participation certificate evidencing the
                  Purchased Portion of the CEC Loan or such





SEVEN SEAS PETROLEUM INC.                                           Exhibit "G"
LOAN PURCHASE AGREEMENT                                       Page 2 of 6 Pages

<PAGE>   51




                  other evidence as is reasonably acceptable to the parties
                  evidencing the Hefner Parties' ownership of the Purchased
                  Portion; and (b) the required portion of the Warrants. The
                  Hefner Parties will deliver to Chesapeake in immediately
                  available funds the Purchase Price. The parties hereby agree:
                  (x) the Purchased Portion and the Warrants to be assigned
                  under this Agreement will be assigned "AS IS WHERE IS" without
                  any representation, warranty, recourse or liability in any
                  event; (y) to use reasonable efforts to cause the Borrower to
                  issue a separate warrant agreement for the warrants to be
                  assigned to the Hefner Parties; and (z) in the event that a
                  separate warrant agreement is not issued, to take such actions
                  as may be reasonable for Chesapeake to hold the Warrants to be
                  assigned hereunder as agent for the Hefner Parties.

4. Voting Agreement. Under the terms of the Shareholders Rights Agreement of
even date herewith among Chesapeake and the Borrower, Chesapeake has the right
to request representation on the Borrower's board of directors by persons
designated by Chesapeake. In the event that Chesapeake exercises such rights,
each of the Hefner Parties agrees to take all action necessary including, but
not limited to, the voting of such Hefner Party's capital stock, the execution
of written consents, the calling of special meetings, the removal of directors,
the filling of vacancies on the Borrower's board of directors, the waiving of
notice and the attending of meetings, so as to cause Chesapeake's designees to
be voted or appointed to the Borrower's board of directors. The foregoing
expressly includes causing the foregoing actions to be taken or performed by any
affiliates of the Hefner Parties. Notwithstanding the foregoing, Hefner shall
not be required to take any action that, in the opinion of counsel, would
violate his fiduciary duties to the Borrower and its shareholders.

5. Miscellaneous. It is further agreed as follows:

         5.1      Default. The parties agree that a violation by any party of
                  the terms of this Agreement cannot be adequately measured or
                  compensated in money damages and that any breach or threatened
                  breach of this Agreement by a party to this Agreement would do
                  irreparable injury to the non-breaching party. The parties,
                  therefore, agree that in the event of any breach or threatened
                  breach by a party to this Agreement of the terms and
                  conditions set forth in this Agreement, the non-breaching
                  party will be entitled, in addition to any and all other
                  rights and remedies that it may have in law or in equity, to
                  apply for and obtain injunctive relief requiring the breaching
                  party to be restrained from any such breach, or threatened
                  breach or to refrain from a continuation of any actual breach.

         5.2      Headings. The section headings in, and the table of contents
                  of, this Agreement are for convenience of reference only and
                  are not part of the substance of this Agreement. References in
                  this Agreement to paragraphs are references to the paragraphs
                  of this Agreement unless otherwise specified.

         5.3      Severability. The parties to this Agreement expressly agree
                  that it is not their intention to violate any public policy,
                  law, statutory or common law rules or the regulations or
                  decisions of any governmental or regulatory body. If any
                  provision of this Agreement is judicially or administratively
                  interpreted or construed as being in


SEVEN SEAS PETROLEUM INC.                                           Exhibit "G"
LOAN PURCHASE AGREEMENT                                       Page 3 of 6 Pages

<PAGE>   52



                  violation of any such policy, law, rule, regulation or
                  decision, the provision causing such violation will be
                  inoperative (and in lieu thereof there will be inserted such
                  provision as may be valid and consistent with the intent of
                  the parties under this Agreement) and the remainder of this
                  Agreement, as amended, will remain binding upon the parties to
                  this Agreement, unless the inoperative provision would cause
                  enforcement of the remainder of this Agreement to be
                  inequitable under the circumstances.

         5.4      Notices. Any notice, demand or communication required or
                  permitted to be given by any provision of this Agreement will
                  be in writing and will be deemed to have been given and
                  received when delivered personally or by telefacsimile to the
                  party designated to receive such notice, or on the date
                  following the day sent by overnight courier, or on the third
                  (3rd) business day after the same is sent by certified mail,
                  postage and charges prepaid, directed to the addresses of the
                  parties set forth below or to such other address as each party
                  may designate for itself by like notice:

<Table>
<S>                                          <C>
                  To Chesapeake:             Chesapeake Energy Corporation
                                             Attention: Marcus C. Rowland
                                             6100 North Western
                                             Oklahoma City, Oklahoma  73118
                                             Telefacsimile: (405) 879-9580

                                             with a copy to

                                             Commercial Law Group, P.C.
                                             Attention: Ray Lees
                                             2725 Oklahoma Tower
                                             210 Park Avenue
                                             Oklahoma City, Oklahoma  73102
                                             Telefacsimile:  (405) 232-5553

                  To the Hefner Parties:     Mr. Robert A. Hefner III
                                             Ramiiilaj, A Limited Partnership
                                             c/o Robert S. May
                                             6305 Waterford Blvd., Suite 470
                                             Oklahoma City, Oklahoma 73118
                                             Telefacsimile:  (405) 858-9898

                                             with copy to:

                                             Gary F. Fuller
                                             McAfee & Taft, A Professional Corporation
                                             10th Floor, Two Leadership Square
                                             211 North Robinson
                                             Oklahoma City, Oklahoma 73102
                                             Telefacsimile:  (405) 235-0439
</Table>


SEVEN SEAS PETROLEUM INC.                                           Exhibit "G"
LOAN PURCHASE AGREEMENT                                       Page 4 of 6 Pages
<PAGE>   53



         5.5      Successors. This Agreement will be binding upon and inure to
                  the benefit of the parties and their respective successors and
                  permitted assigns.

         5.6      Remedies. The failure of any party to enforce any right or
                  remedy under this agreement, or to enforce any such right or
                  remedy promptly, will not constitute a waiver thereof, nor
                  give rise to any estoppel against such party, nor excuse any
                  other party from its obligations under this Agreement. Any
                  waiver of any such right or remedy by any party must be in
                  writing and signed by the party against which such waiver is
                  sought to be enforced, will be narrowly construed only as a
                  waiver of the particular matter stated to be waived, and will
                  not constitute a continuing waiver.

         5.7      Survival. All warranties, representations and covenants made
                  by any party in this Agreement or in any certificate or other
                  instrument delivered by such party or on its behalf under this
                  Agreement will be considered to have been relied upon by the
                  party to which it is delivered and will survive the execution
                  of this Agreement, regardless of any investigation made by
                  such party or on its behalf. All statements in any such
                  certificate or other instrument will constitute warranties and
                  representations under this Agreement.

         5.8      Fees. If any party institutes an action or proceeding against
                  any other party relating to the provisions of this Agreement
                  or any default hereunder, the unsuccessful party to such
                  action or proceeding will reimburse the successful party
                  therein for the reasonable expenses of attorneys' fees and
                  disbursements and litigation expenses incurred by the
                  successful party.

         5.9      Counterparts. This Agreement may be executed in any number of
                  counterparts, which will individually and collectively
                  constitute one agreement.

         5.10     CHOICE OF LAW. THIS AGREEMENT WILL BE GOVERNED BY AND
                  INTERPRETED IN ACCORDANCE WITH THE INTERNAL LAWS OF THE STATE
                  OF OKLAHOMA APPLICABLE TO AN AGREEMENT EXECUTED, DELIVERED AND
                  PERFORMED THEREIN WITHOUT GIVING EFFECT TO THE CHOICE-OF-LAW
                  RULES THEREOF OR ANY OTHER PRINCIPLE THAT COULD REQUIRE THE
                  APPLICATION OF THE SUBSTANTIVE LAW OF ANY OTHER JURISDICTION.

                  IN WITNESS HEREOF, the parties have executed this Agreement
effective as of the date first above written.



                                 CHESAPEAKE ENERGY CORPORATION,
                                 an Oklahoma corporation


                                 By
                                   --------------------------------------------
                                   Aubrey K. McClendon, Chief Executive Officer
                                   ("Chesapeake")


SEVEN SEAS PETROLEUM INC.                                           Exhibit "G"
LOAN PURCHASE AGREEMENT                                       Page 5 of 6 Pages

<PAGE>   54




                                 ----------------------------------------------
                                 ROBERT A. HEFNER III, individually

                                 RAMIIILAJ, A LIMITED PARTNERSHIP, a Texas
                                 limited partnership

                                 By:  Hefner Investment Company,
                                      an Oklahoma corporation,
                                      sole general partner


                                      By
                                        ---------------------------------------
                                        Robert A. Hefner III, President



SEVEN SEAS PETROLEUM INC.                                           Exhibit "G"
LOAN PURCHASE AGREEMENT                                       Page 6 of 6 Pages