<PAGE>
 
assigned by any of the parties hereto without the prior written consent of the
other affected party.

  9.8  Severability.  If any provision of this Agreement is found by a court of
competent jurisdiction to be invalid or unenforceable, that provision will be
deemed modified to the extent necessary to make it valid and enforceable and if
it cannot be so modified, it shall be deemed deleted and the remainder of the
Agreement shall continue and remain in full force and effect.

  9.9  Counterparts.  This Agreement may be executed in counterparts, each of
which shall constitute an original and all of which shall constitute one
document.

  9.10  Governing Law.  This Agreement shall be governed by the laws of the
State of Texas as to the sale of the Texas Assets and by the laws of Oklahoma as
to the sale of the Oklahoma Assets, excluding any provision of Texas or Oklahoma
law that would apply the law of another jurisdiction.

  9.11  Bulk Sales Waiver.  All parties hereto waive any and all compliance by
any party with the requirements of any bulk sales act concerning or relating to
the transactions contemplated by this Agreement.

  9.12  Trident NGL Agreement.  Pursuant to Section 11.7 of the Purchase and
Sale Agreement dated January 13, 1993 (the "TRIDENT NGL AGREEMENT") by and
between Trident NGL, Inc., as seller, and Cimarron Gas Holding Company, as
buyer, the Seller hereby, to the extent permitted by the Trident NGL Agreement,
makes those Oklahoma Assets which were assets purchased by Seller pursuant to
the Trident NGL Agreement subject to the indemnity provisions set forth in
Article IV and V of the Trident NGL Agreement.

 9.13  Arbitration.

          (i) All disputes, differences or questions arising out of or relating
              to this Agreement (including, without limitation, those as to the
              validity, interpretation, breach, violation or termination hereof)
              shall, at the written request of any party hereto, be finally
              determined and settled pursuant to binding arbitration in Houston,
              Texas, by three arbitrators, one to be appointed by Buyers, and
              one by Seller, and a neutral arbitrator to be appointed by such
              two appointed arbitrators. The neutral arbitrator shall be an
              attorney and shall act as chairman. Should (a) either party fail
              to appoint an arbitrator as hereinabove contemplated within ten
              (10) days after the party not requesting arbitration has received
              such written request, or (b) the two arbitrators appointed by or
              on behalf of the parties as contemplated by this Section 9.13 fail
              to appoint a neutral arbitrator as hereinabove contemplated within
              ten (10) days after the date of the appointment of the last
              arbitrator appointed, then any person sitting as a Judge of the
              United States

                                       30