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                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                                  SCHEDULE 13D

                    Under the Securities Exchange Act of 1934

                            SEVEN SEAS PETROLEUM INC.


                                 --------------
                                (Name of Issuer)

                        Ordinary Shares, par value $.001


                              ---------------------
                         (Title of Class of Securities)

                                    G80550109
                                 ---------------
                                 (CUSIP Number)

                              Shannon Self, Esquire
                           Commercial Law Group, P.C.
                               2725 Oklahoma Tower
                                 210 Park Avenue
                          Oklahoma City, Oklahoma 73102
                                 (405) 232-3001

                            ------------------------
                  (Name, Address and Telephone Number of Person
                Authorized to Receive Notices and Communications)

                                 August 15, 2001

                            ------------------------
             (Date of Event Which Requires Filing of this Statement)

If the filing person has previously filed a statement on Schedule 13G to report
the acquisition which is the subject of this Schedule 13D, and is filing this
schedule because of Rule 13d-1(b)(3) or (4), check the following box. [ ]

NOTE: Six (6) copies of this statement, including all exhibits, should be filed
with the Commission. See Rule 13d-1(a) for other parties to whom copies are to
be sent.

* The remainder of this cover page shall be filled out for a reporting person's
initial filing on this form with respect to the subject class of securities, and
for any subsequent amendment containing information which would alter
disclosures provided in a prior cover page.

The information required on the remainder of this cover page shall not be deemed
to be "filed" for the purpose of Section 18 of the Securities Exchange Act of
1934 ("Act") or otherwise subject to the liabilities of that section of the Act
but shall be subject to all other provisions of the Act (however, see the
Notes).


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CUSIP NO. G80550109



                                                                
   (1)     Name of Reporting Person                                       Chesapeake Energy
                                                                                Corporation
           S.S. or I.R.S. Identification No. of Above Person                     73-1395733

   (2)     Check the Appropriate Box if a Member of a Group                       (a)   [ ]
           (See Instructions)                                                     (b)   [x]

   (3)     SEC Use Only

   (4)     Source of Funds (See Instructions)                                            WC

   (5)     Check if Disclosure of Legal Proceedings  is Required                       [  ]
           Pursuant to Items 2(d) or 2(e)

   (6)     Citizenship or Place of Organization                                    Oklahoma

Number of Shares              (7)   Sole Voting Power                            12,619,500
Beneficially Owned            (8)   Shared Voting Power                                   -
By Each Reporting             (9)   Sole Disposition                             12,619,500
Person With:                  (10)  Shared Dispositive Power                              -

  (11)     Aggregate Amount Beneficially Owned by Each                           12,619,500
           Reporting Person

  (12)     Check if the Aggregate Amount in Row (11) Excludes                          [  ]
           Certain Shares (See Instructions)

  (13)     Percent of Class Represented by Amount in Row (11)                         25.0%

  (14)     Type of Reporting Person (See Instructions)                                   CO





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CUSIP NO. G80550109


Item 1.  Security and Issuer.

         The ordinary shares, par value $.001 (the "Ordinary Shares"), of Seven
         Seas Petroleum Inc., a Cayman Islands exempted company limited by
         shares ("Seven Seas"). Seven Seas' principal executive offices are
         located at Suite 1700, 5555 San Felipe, Houston, Texas 77056.

Item 2.  Identity and Background.

         Chesapeake Energy Corporation, an Oklahoma corporation ("Chesapeake
         Energy"), is located at 6100 North Western Avenue, Oklahoma City,
         Oklahoma 73118, and is primarily engaged in the ownership, development
         and operation of oil and gas assets in North America. The executive
         officers and directors of Chesapeake Energy are set forth below.

                  Aubrey K. McClendon
                  Chairman of the Board  and Chief Executive Officer
                  6100 North Western
                  Oklahoma City, Oklahoma 73118

                  Tom L. Ward
                  Director, Chief Operating Officer and President
                  6200 North Western
                  Oklahoma City, Oklahoma 73118

                  Marcus C. Rowland
                  Chief Financial Officer and Executive Vice President
                  6100 North Western
                  Oklahoma City, Oklahoma 73118

                  Martha A. Burger
                  Treasurer and Senior Vice President
                  6100 North Western
                  Oklahoma City, Oklahoma 73118

                  Michael A. Johnson
                  Senior Vice President
                  6100 North Western
                  Oklahoma City, Oklahoma 73118

                  Edgar F. Heizer, Jr.
                  Director
                  c/o  Chesapeake Energy Corporation
                  6100 North Western
                  Oklahoma City, Oklahoma 73118



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CUSIP NO. G80550109


                  Breene M. Kerr
                  Director
                  c/o  Chesapeake Energy Corporation
                  6100 North Western
                  Oklahoma City, Oklahoma 73118

                  Shannon Self
                  Director
                  c/o  Chesapeake Energy Corporation
                  6100 North Western
                  Oklahoma City, Oklahoma 73118

                  Frederick B. Whittemore
                  Director
                  c/o  Chesapeake Energy Corporation
                  6100 North Western
                  Oklahoma City, Oklahoma 73118

         Chesapeake Energy and each of the listed individuals have not, during
         the last five years, been convicted in a criminal proceeding and have
         not been or become subject to a judgment, decree or final order
         enjoining future violations of, or prohibiting or mandating activities
         subject to, federal or state securities laws or finding any violation
         with respect to such laws. Each individual is a United States citizen.

Item 3.  Source and Amount of Funds or Other Consideration

         Pursuant to that certain Note Purchase and Loan Agreement dated
         effective July 9, 2001 (the "Loan Agreement"), Chesapeake Energy agreed
         to purchase a $22.5 million 12% secured note due 2004 issued by Seven
         Seas (the "Chesapeake Loan"), accompanied by a warrant to purchase
         Ordinary Shares of Seven Seas. The funding of the Chesapeake Loan was
         conditioned on the extension of a second $22.5 million secured bridge
         loan by certain shareholders of Seven Seas on similar terms (the
         "Shareholder Loans") pending the completion of a rights offering by
         Seven Seas (the "Rights Offering"). The Rights Offering will grant to
         Seven Seas' shareholders the right to participate on a prorata basis in
         the purchase of $22.5 million of Seven Seas' Series A Senior Secured
         Notes (the "Series A Notes") and warrants to purchase 12,619,500
         Ordinary Shares on terms substantially similar to those under the
         Chesapeake Loan and the accompanying warrant. The proceeds from the
         Rights Offering will be used to pay the Shareholder Loans. If there is
         insufficient participation by Seven Seas' shareholders in the Rights
         Offering to sell all of the Series A Notes, the participants in the
         Shareholder Loans have agreed to acquire any shortfall through an
         exchange of the Shareholder Loans.

         The Chesapeake Loan was funded on July 24, 2001, and is evidenced by
         that certain Promissory Note executed by Seven Seas and dated July 23,
         2001, in the amount of $22.5 million. As partial consideration for the



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CUSIP NO. G80550109


         Chesapeake Loan, Seven Seas granted to Chesapeake Energy the right to
         purchase 12,619,500 Ordinary Shares as evidenced by that certain
         Amended and Restated Warrant No. 1 dated July 23, 2001 (the "Warrant").
         The Warrant amends and restates in its entirety the original warrant
         issued as part of the Chesapeake Loan in order to correct the number of
         securities covered by the Warrant due to a calculation error in the
         original warrant of approximately 7,000 shares. The Chesapeake Loan was
         funded by Chesapeake Energy from working capital and general corporate
         funds, one of the sources of which is the revolving bank facility
         maintained by Chesapeake Energy and its subsidiary entities.

Item 4.  Purpose of Transaction

         The Chesapeake Loan and the Warrant were acquired by Chesapeake Energy
         as investments. Chesapeake Energy may in the future: (a) purchase
         additional Ordinary Shares, debt securities or other equity securities
         of Seven Seas; (b) sell all or part of the Warrant or the Ordinary
         Shares acquired through the exercise of the Warrant; (c) communicate
         with management of Seven Seas regarding Seven Seas' business plans and
         operations; or (d) enter into additional transactions in connection
         with Seven Seas or Seven Seas' assets.

         In connection with the Chesapeake Loan, Chesapeake Energy was granted:
         (x) the right to request the appointment of up to two directors to
         Seven Seas' board of directors; (y) the preemptive right to acquire
         equity securities to be issued by Seven Seas in the future; and (z) the
         right to require Mr. Robert A. Hefner III ("Hefner") and Ramiiilaj, A
         Limited Partnership, a Texas limited partnership, affiliated with
         Hefner ("Ramiiilaj" and together with Hefner, the "Hefner Parties"), to
         purchase a portion of the Chesapeake Loan and the Warrant if the amount
         of Series A Notes purchased by the Hefner Parties as part of the Rights
         Offering is less than $10.0 million. Hefner is the Chairman of the
         Board of Seven Seas. As part of the transaction Seven Seas pledged all
         of the outstanding capital stock of all of Seven Seas' subsidiaries to
         secure the Chesapeake Loan, the Shareholder Loans and the Series A
         Notes.

         In addition, the Loan Agreement and the documents evidencing the pledge
         of the capital stock of Seven Seas' subsidiaries impose a number of
         affirmative and negative covenants on Seven Seas and Seven Seas'
         subsidiaries which are normally included in lending transactions
         similar to the Chesapeake Loan. To date Chesapeake Energy has not
         exercised any of the foregoing rights. Except as set forth above,
         Chesapeake Energy has no present plans or intentions relating to the
         transactions described in subparagraphs (a) through (d) of Item 4 of
         Schedule 13D.

Item 5.  Interest in Securities of the Issuer.

         (a) Under the terms of the Warrant Chesapeake Energy has the right to
         acquire up to 12,619,500 Ordinary Shares at any time after October 15,
         2001, and before June 30, 2008. Based on the 37,858,501 Ordinary Shares
         reflected as issued and outstanding in Seven Seas' Form 10Q\A filed on
         May 16, 2001, the Ordinary Shares which can be acquired by



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CUSIP NO. G80550109


         Chesapeake Energy under the Warrant would represent 25.0% of the
         outstanding Ordinary Shares after giving effect to the exercise of the
         Warrant.

         (b) Chesapeake Energy has the sole power to dispose of the Warrant and
         will have the sole right to vote or dispose of the Ordinary Shares to
         be received on the exercise of the Warrant.

         (c) Chesapeake Energy acquired the Warrant effective July 23, 2001, in
         connection with the Chesapeake Loan. The Warrant permits Chesapeake
         Energy to acquire 12,619,500 Ordinary Shares for $22.5 million, which
         results in an exercise price for each Ordinary Share of approximately
         $1.78295. As part of the Chesapeake Loan, Chesapeake Energy and the
         Hefner Parties entered into the Loan Purchase Agreement dated effective
         July 23, 2001 (the "LPA"). Under the LPA, if the Hefner Parties
         purchase less than $10.0 million of Series A Notes in the Rights
         Offering Chesapeake Energy can require the Hefner Parties to purchase
         that portion of the Chesapeake Loan and the Warrant which would result
         in the Hefner Parties holding Series A Notes and a portion of the
         Chesapeake Loan in the aggregate principal amount of $10.0 million.

         (d)      Inapplicable

         (e)      Inapplicable

Item 6. Contracts, Agreements, Underwritings or Relationships With Respect to
Securities of the Is suer.

         Under that certain Shareholder's Rights Agreement between Seven Seas
         and Chesapeake Energy dated July 23, 2001 (the "Shareholder's
         Agreement"), Chesapeake Energy has the preemptive right to participate
         in future equity issuances by Seven Seas, has the right to request the
         appointment of two directors to Seven Seas' board of directors and the
         right to attend and observe all board meetings of Seven Seas and Seven
         Seas' subsidiaries. Under the LPA, the Hefner Parties agree to: (a)
         vote any Ordinary Shares held by the Hefner Parties for the persons
         which Chesapeake Energy requests be appointed to Seven Seas' board of
         directors under the Shareholder's Agreement; and (b) purchase a portion
         of the Chesapeake Loan as described in Item 5(c) above. Under a
         Registration Rights Agreement between Seven Seas and Chesapeake Energy
         dated July 23, 2001, the holders of at least 25.0% of the Ordinary
         Shares underlying the Warrant can request the registration of such
         Ordinary Shares.

Item 7.  Materials to be filed as Exhibits.

1.       Warrant No. 1 dated July 23, 2001, between Seven Seas Petroleum Inc.
         and Chesapeake Energy Corporation is filed as Exhibit No. 4(B) to the
         Form 10Q filed by Seven Seas Petroleum Inc. on August 14, 2001, and is
         incorporated herein by reference.


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CUSIP NO. G80550109


2.       Amended and Restated Warrant No. 1 dated July 23, 2001, between Seven
         Seas Petroleum Inc. and Chesapeake Energy Corporation is attached
         hereto as Exhibit 99.1.

3.       Shareholder's Rights Agreement dated July 23, 2001, between Seven Seas
         Petroleum Inc. and Chesapeake Energy Corporation is filed as Exhibit
         No. 4(C) to the Form 10Q filed by Seven Seas Petroleum Inc. on August
         14, 2001, and is incorporated herein by reference.

4.       Loan Purchase Agreement dated effective July 23, 2001, among Chesapeake
         Energy Corporation, Robert A. Hefner III and Ramiiilaj, A Limited
         Partnership, is attached hereto as Exhibit 99.2.

5.       Registration Rights Agreement dated July 23, 2001, between Seven Seas
         Petroleum Inc. and Chesapeake Energy Corporation is filed as Exhibit
         No. 4(D) to the Form 10Q filed by Seven Seas Petroleum Inc. on August
         14, 2001, and is incorporated herein by reference.

6.       Note Purchase and Loan Agreement dated effective July 9, 2001, among
         Chesapeake Energy Corporation, Seven Seas Petroleum Inc., and the
         subsidiaries of Seven Seas Petroleum Inc., is filed as Exhibit No.
         10(A) to the Form 10Q filed by Seven Seas Petroleum Inc. on August 14,
         2001, and is incorporated herein by reference.

7.       First Amendment to Note Purchase and Loan Agreement dated effective
         July 9, 2001, among Chesapeake Energy Corporation, Seven Seas Petroleum
         Inc., and the subsidiaries of Seven Seas Petroleum Inc., is filed as
         Exhibit No. 10(B) to the Form 10Q filed by Seven Seas Petroleum Inc.
         on August 14, 2001, and is incorporated herein by reference.

8.       Security Agreement dated effective July 23, 2001 between Seven Seas
         Petroleum Inc. and Chesapeake Energy Corporation is filed as Exhibit
         No. 10(C) to the Form 10Q filed by Seven Seas Petroleum Inc. on August
         14, 2001, and is incorporated herein by reference.

9.       Deeds of Mortgage Over Shares dated July 23, 2001 between Seven Seas
         Petroleum Inc. and Chesapeake Energy Corporation is filed as Exhibit
         No. 10(D) to the Form 10Q filed by Seven Seas Petroleum Inc. on August
         14, 2001, and is incorporated herein by reference.



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CUSIP NO. G80550109


                                    SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify
that the information set forth in this statement is true, complete and correct.

DATED:            August 27, 2000




                                  Chesapeake Energy Corporation, an Oklahoma
                                  corporation



                                  By    /s/ Aubrey K. McClendon
                                    -------------------------------------------
                                    Aubrey K. McClendon, Chairman of the Board
                                    and Chief Executive Officer










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                                  EXHIBIT INDEX





EXHIBIT
NUMBER         DESCRIPTION
------         -----------
            
99.1           Amended and Restated Warrant No. 1

99.2           Loan Purchase Agreement