EXHIBIT 3.6(a)

                          CERTIFICATE OF INCORPORATION

                                       OF

                                EAP ENERGY, INC.

      I, the undersigned natural person acting as an incorporator of a
corporation (the "Company") under the General Corporation Law of the State of
Delaware (the "Delaware General Corporation Law"), do hereby adopt the following
Certificate of Incorporation (the "Certificate") for the Company:

                                  ARTICLE ONE

      The name of the Company is EAP Energy, Inc.

                                  ARTICLE TWO

      The registered office of the Company in the State of Delaware is located
at 1209 Orange Street, County of New Castle, Wilmington, Delaware 19801. The
name of its Registered Agent at the above address is Corporation Trust Company.

                                 ARTICLE THREE

      The purpose of the Company is to engage in any lawful act or activity for
which a corporation may be organized under the Delaware General Corporation Law.

                                  ARTICLE FOUR

      The total number of shares of capital stock that the Company has authority
to issue is 1,000 shares, which will be designated Common Stock, par value $.01
per share.

                                  ARTICLE FIVE

      The name and mailing address of the Incorporator are as follows:

               Name                             Address

               Edward K. Clark                  201 Main Street
                                                Suite 2500
                                                Fort Worth, Texas 76102

                                  ARTICLE SIX

      Unless, and except to the extent that, the By-Laws of the Company (the
"By-Laws") so require, the election of directors need not be by written ballot.



                                 ARTICLE SEVEN

      The board of directors of the Company (the "Board of Directors") may from
time to time adopt, amend or repeal the By-Laws, subject to the power of the
stockholders to adopt any By-Laws or to amend or repeal any By-Laws adopted,
amended or repealed by the Board of Directors.

                                  ARTICLE EIGHT

      To the fullest extent that the Delaware General Corporation Law as it
exists on the date hereof or as it may hereafter be amended permits the
limitation or elimination of the liability of directors, no director will be
liable to the Company or its stockholders for monetary damage for breach of
fiduciary duty as a director. Any repeal or amendment of this Article will not
adversely affect any limitation on the personal liability or alleged liability
of a director arising from an act or omission of that director occurring prior
to the time of such repeal or amendment.

      THE UNDERSIGNED INCORPORATOR, for the purposes of forming the corporation,
does make and file this Certificate of Incorporation, hereby declaring and
certifying that the facts herein stated are true and accordingly has set his
hand on February 23, 1999.

                                          /s/  Edward K. Clark
                                          --------------------------------------
                                          Edward K. Clark, Incorporator

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