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                       AMENDMENT NO. 1 TO CREDIT AGREEMENT


     THIS AMENDMENT NO. 1 TO CREDIT AGREEMENT (this "AMENDMENT NO. 1"),
dated as of January 24, 2001, between ESENJAY EXPLORATION, INC., a
Delaware corporation (the "BORROWER"), and DEUTSCHE BANK AG, New York
and/or Cayman Islands Branch (the "LENDER"),


                             W I T N E S S E T H:


     WHEREAS, the Borrower and the Lender are parties to that certain Credit
Agreement, dated as of January 25, 2000 (as the same has been from
time-to-time amended, hereinafter referred to as the "EXISTING CREDIT
AGREEMENT"); and

     WHEREAS, the Borrower has requested that certain amendments be made to
the Existing Credit Agreement; and

     WHEREAS, the Lender is willing to make certain amendments to the
Existing Credit Agreement on the terms and conditions hereinafter provided;
and

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

                                  ARTICLE I.

                                 DEFINITIONS

     SECTION 1.1 CERTAIN DEFINITIONS. The following terms (whether or not
underscored) when used in this Amendment No. 1 shall have the following
meanings:

     "AMENDED CREDIT AGREEMENT" means the Existing Credit Agreement as
amended by this Amendment No. 1.

     SECTION 1.2 OTHER DEFINITIONS. Unless otherwise defined or the context
otherwise requires, terms used herein (including in the preamble and recitals
hereto) have the meanings provided for in the Existing Credit Agreement.

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                                  ARTICLE II.

                                 AMENDMENT TO
                           EXISTING CREDIT AGREEMENT

     Effective as of January 24, 2001, the Existing Credit Agreement is
amended in accordance with the terms of this ARTICLE II; except as so
amended, the Existing Credit Agreement shall continue to remain in all
respects in full force and effect.

     SECTION 2.1 AMENDMENT TO SECTION 1.1.

          (a) SECTION 1.1 is hereby amended by deleting the text of the
     existing definition of "Tranche A Availability Termination Date" and
     inserting the following definition in its place in SECTION 1.1:

     "TRANCHE A AVAILABILITY TERMINATION DATE" means February 23, 2001.


                                 ARTICLE III.

                         REPRESENTATIONS AND WARRANTIES

     In order to induce the Lender to make the amendments provided for in
ARTICLE II, the Borrower hereby

          (a) represents and warrants that the Borrower has full power and
     authority to execute, deliver and perform its obligations under this
     Amendment No. 1 and all other Loan Documents delivered to Lender in
     connection herewith, and this Amendment No. 1 and all such Loan Documents
     are the legally valid and binding obligations of Borrower, enforceable
     against Borrower in accordance with their respective terms;

          (b) represents and warrants that each of the representations and
     warranties contained in the Existing Credit Agreement and in the other
     Loan Documents is true and correct as of the date hereof as if made on
     the date hereof (except, if any such representation and warranty relates
     to an earlier date, such representation and warranty shall be true and
     correct in all material respects as of such earlier date) and Borrower
     has performed each of the covenants and agreements in the Existing Credit
     Agreement and the other Loan Documents required to be performed by
     Borrower as of the date hereof;

                                       -2-

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          (c) represents and warrants that there is no Default or Event of
     Default by Borrower or any other Obligor under the Existing Credit
     Agreement or any other Loan Document and no event exists which, with the
     giving of notice or the passage of time or both, would give rise to a
     Default or Event of Default by Borrower or any other Obligor under the
     Existing Credit Agreement or any Loan Document.

                                    ARTICLE IV.

                             CONDITIONS TO EFFECTIVENESS

     SECTION 4.1 EFFECTIVENESS. This Amendment No. 1 shall become effective
when the conditions set forth in this SECTION 4.1 have been satisfied:

          (a) EXECUTION OF COUNTERPARTS. The Lender shall have received
    counterparts of this Amendment No. 1 duly executed and delivered on behalf
    of the Borrower and the Lender.

          (b) CLOSING FEES, EXPENSES, ETC. The Lender shall have received all
    reasonable costs and expenses due and payable pursuant to SECTIONS 3.3 and
    10.3 of the Existing Credit Agreement, if then invoiced.

          (c) LEGAL DETAILS, ETC. All documents executed or submitted pursuant
    hereto, and all legal matters incident thereto, shall be satisfactory in
    form and substance to the Lender and its counsel.


                                     ARTICLE V.

                                    MISCELLANEOUS

     SECTION 5.1 LOAN DOCUMENT PURSUANT TO EXISTING CREDIT AGREEMENT. This
Amendment No. 1 is a Loan Document executed pursuant to the Existing Credit
Agreement. Except as expressly amended or waived hereby, all of the
representations, warranties, terms, covenants and conditions contained in the
Existing Credit Agreement and each other Loan Document shall remain unamended
and in full force and effect. The amendments set forth herein shall be
limited precisely as provided for herein and shall not be deemed to be a
waiver of, amendment of, consent to or modification of any other term or
provision of the Existing Credit Agreement or of any term or provision of any
other Loan Document or of any transaction or further or future action on the
part of the Borrower which would require the consent of the Lender under the
Existing Credit Agreement or any other Loan Document.


                                           -3-

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     SECTION 5.2 COUNTERPARTS, ETC. This Amendment No. 1 may be executed by
the parties hereto in several counterparts, each of which shall be deemed to
be an original and all of which shall constitute together but one and the
same agreement with the same effect as if all parties hereto had signed the
same signature page. Any signature page of this Amendment No. 1 may be
detached from any identical counterpart of this Amendment No. 1 having
attached to it one or more additional signature pages.

     SECTION 5.3 GOVERNING LAW; ENTIRE AGREEMENT. THIS AMENDMENT NO. 1 SHALL
BE DEEMED TO BE A CONTRACT MADE UNDER AND GOVERNED BY THE INTERNAL LAWS OF
THE STATE OF NEW YORK.

     SECTION 5.4 TITLES AND HEADINGS. The titles and headings of the Sections
of this Amendment No. 1 are intended for convenience only and shall not in
any way affect the meaning or construction of any provision of this Amendment
No. 1.

     SECTION 5.5 CHANGES AND MODIFICATIONS IN WRITING. No provision of this
Amendment No. 1 may be changed or modified except by an instrument in writing
signed by the party against whom enforcement of the change or modification is
sought.


                                       -4-

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     IN WITNESS WHEREOF, the parties hereto have caused this Amendment No. 1
to be executed by their respective officers hereunto duly authorized as of
the day and year first above written.

                                       BORROWER

                                       ESENJAY EXPLORATION, INC., a Delaware
                                       corporation



                                       By:     /s/ David B. Christofferson
                                               --------------------------------
                                       Name:   David B. Christofferson
                                       Title:  Senior Vice President


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                                        LENDER

                                        DEUTSCHE BANK AG, NEW YORK AND/OR
                                        CAYMAN ISLANDS BRANCH



                                        By:    /s/ Kurt A. Schreder
                                               --------------------------------
                                        Name:  KURT A. SCHREDER
                                        Title: Vice President


                                        By:    /s/ Kerri L. Fox
                                               --------------------------------
                                        Name:  KERRI L. FOX
                                        Title: Vice President