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                                                                     EXHIBIT 3.5

                                                                  PAGE 1

                                STATE OF DELAWARE
                        OFFICE OF THE SECRETARY OF STATE
                      ------------------------------------


         I, EDWARD J. FREEL, SECRETARY OF STATE OF THE STATE OF DELAWARE, DO
HEREBY CERTIFY THE ATTACHED IS A TRUE AND CORRECT COPY OF THE CERTIFICATE OF
AGREEMENT OF MERGER, WHICH MERGES:

         "MWJR PETROLEUM CORPORATION", A DELAWARE CORPORATION,

         WITH AND INTO "APACHE CORPORATION" UNDER THE NAME OF" APACHE
CORPORATION", A CORPORATION ORGANIZED AND EXISTING UNDER THE LAWS OF THE STATE
OF DELAWARE, AS RECEIVED AND FILED IN THIS OFFICE THE NINETEENTH DAY OF AUGUST,
A.D. 1998, AT 8:30 O'CLOCK A.M.

         AND I DO HEREBY FURTHER CERTIFY THAT THE EFFECTIVE DATE OF THE
AFORESAID CERTIFICATE OF AGREEMENT OF MERGER IS THE FIRST DAY OF SEPTEMBER, A.D.
1998.

         A FILED COPY OF THIS CERTIFICATE HAS BEEN FORWARDED TO THE NEW CASTLE
COUNTY RECORDER OF DEEDS.


                                       /s/ Edward J. Freel
                                       -----------------------------------------
                                       Edward J. Freel, Secretary of State

                                     [SEAL]

     0482215  8100M                               AUTHENTICATION:  9260798
     981324877                                              DATE:  08-19-98



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                          AGREEMENT AND PLAN OF MERGER


                                     BETWEEN
                               APACHE CORPORATION
                                       AND
                           MWJR PETROLEUM CORPORATION


AGREEMENT AND PLAN OF MERGER ("Agreement"), dated this 7th day of August, 1998,
pursuant to Section 251 of the General Corporation Law of the State of Delaware,
between Apache Corporation, a Delaware corporation, and MWJR Petroleum
Corporation, a Delaware corporation (together, the "Constituent Corporations").

WITNESSETH that:

WHEREAS, both of the Constituent Corporations desire to merge into a single
corporation; and

NOW THEREFORE, the corporations, parties to this Agreement, in consideration of
the mutual covenants, agreements and provisions hereinafter contained do hereby
prescribe the terms and conditions of said merger and the mode of carrying the
same into effect as follows:

         FIRST: MWJR Petroleum Corporation (the "Merged Corporation") at the
effective time shall be merged with and into Apache Corporation, which shall be
the surviving corporation (the "Surviving Corporation").

         SECOND: The Restated Certificate of Incorporation of Apache
Corporation, as heretofore amended and as in effect on the date of the merger
provided for in this Agreement, shall continue in full force and effect as the
Restated Certificate of Incorporation of the Surviving Corporation.

         THIRD: The effect on the capital stock of each of the Constituent
Corporations shall be as follows:

         (a)  Each share of capital stock of the Surviving Corporation issued
              and outstanding on the effective date of the merger shall remain
              issued and outstanding.

         (b)  Each share of capital stock of the Merged Corporation issued and
              outstanding on the effective date of the merger shall be cancelled
              without consideration, and no shares of the capital stock of the
              Surviving Corporation shall be issued in respect thereof.

         FOURTH: The bylaws of Apache Corporation as they exist on the effective
date of the merger shall be and remain the bylaws of the Surviving Corporation
until the same shall be altered, amended or repealed as therein provided.

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         FIFTH: The directors and officers of Apache Corporation on the
effective date of the merger shall be the directors and officers of the
Surviving Corporation and shall continue in office until the next annual meeting
of stockholders and until their successors shall have been elected and
qualified.

         SIXTH:  This merger shall become on September 1, 1998.

         SEVENTH: Upon the merger becoming effective, all the property, rights
privileges, franchises, patents, trademarks, licenses, registrations and other
assets of every kind and description of the Merged Corporation shall, by
operation of law, be transferred to, vested in, and devolve upon, the Surviving
Corporation without further act or deed, and all property, rights, and every
other interest of the Constituent Corporations shall be as effectively the
property of the Surviving Corporation as they were of the Surviving Corporation
and the Merged Corporation, respectively. The proper officers and directors of
the Surviving Corporation are fully authorized in the name of the Merged
Corporation or otherwise to take any and all action, from time to time, to
execute and deliver or cause to be executed and delivered all such deeds and
instruments and to take or cause to be taken such further or other action as the
Surviving Corporation may deem necessary or desirable in order to vest in and
confirm to the Surviving Corporation title to and possession of any property of
the Merged Corporation acquired or to be acquired by reason of or as a result of
the merger herein provided for and otherwise to carry out the intent and
purposes hereof.

         EIGHTH: Anything herein or elsewhere to the contrary notwithstanding,
this merger may be amended or terminated and abandoned by the Board of Directors
of either of the Constituent Corporations at any time prior to the date of
filing this Agreement with the Delaware Secretary of State.

IN WITNESS WHEREOF, the parties to this Agreement, pursuant to the approval and
authority duly given by resolutions duly adopted by their respective Boards of
Directors, have caused these presents to be executed by the president and
attested by the corporate secretary of each party hereto as the respective act,
deed and agreement of each of said corporations, on this 7th day of August,
1998.


ATTEST:                                APACHE CORPORATION


/s/ Cheri L. Peper                     By: /s/ G. Steven Farris
- -----------------------------------       --------------------------------------
Cheri L. Peper                            G. Steven Farris
Corporate Secretary                       President and Chief Operating Officer


ATTEST:                                MWJR PETROLEUM CORPORATION


/s/ Cheri L. Peper                     By: /s/ G. Steven Farris      
- -----------------------------------       --------------------------------------
Cheri L. Peper                            G. Steven Farris
Corporate Secretary                       President

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         I, Cheri L. Peper, Corporate Secretary of Apache Corporation, a
corporation organized and existing under the laws of the State of Delaware,
hereby certify that the Agreement and Plan of Merger to which this Certificate
is attached, after having been first duly signed on behalf of said Apache
Corporation and having been signed on behalf of MWJR Petroleum Corporation, a
corporation organized and existing under the laws of the State of Delaware, was
duly adopted by action of the Board of Directors of said Apache Corporation and
without any vote of its stockholders pursuant to Section 251(f) of the General
Corporation Law of Delaware and that the conditions specified in the first
sentence of such Section 251(f) have been satisfied.


WITNESS my hand on this 7th day of August, 1998.


                                       /s/ Cheri L. Peper
                                       -----------------------------------------
         [Seal]                        Cheri L. Peper
                                       Corporate Secretary

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