EXHIBIT 10.23

                                  AMENDMENT TO
                        PIONEER NATURAL RESOURCES COMPANY
                               SEVERANCE AGREEMENT


     This Amendment is dated and effective February 19, 2002, and is attached to
and  made a part of  that  certain  Severance  Agreement  ("Agreement")  between
Pioneer Natural  Resources Company  ("Parent") and Larry N. Paulsen  ("Officer")
dated August 8, 1997.

     In  regard  to  the  provisions   relating  to  a  Change  in  Control  and
Termination, paragraph 5(e)(1)(D) is hereby amended as follows:

          "A continuation of  all health  insurance coverage  applicable  at the
     time of such  Termination of  Employment to  Officer and his/her  immediate
     family  under any  Benefit Plan  until  such  Officer  reaches  the  age of
     sixty-five (65),  or the  age upon  which such Officer becomes eligible for
     Medicare benefits as  determined  by the  Social  Security  Administration,
     whichever is later ("Medicare Age");

               "(i) For the first three years of such continued health insurance
          coverage, the premium charged to the Officer shall be the same as that
          charged to parent  company officers  of the  successor  entity  or the
          premium existing prior to the Change in Control, whichever is less;

               (ii) Following  the first  three years  of such  extended  health
          insurance coverage and continuing until such Officer  reaches Medicare
          Age,  the premium for  such coverage  charged the Officer shall be the
          Company's,  or its successor's,  COBRA premium  in effect  during such
          time; and

               (iii) Such health  insurance coverage shall provide benefits at a
          level at least comparable to those  being provided prior to the Change
          in Control, or better if better coverage is  offered to parent company
          officers of the successor entity."

     Except as to the extent modified by this Amendment, the Agreement is hereby
ratified and confirmed in all respects.


                                       PIONEER NATURAL RESOURCES COMPANY



                                       By:      /s/ Mark L. Withrow
                                          ----------------------------------
                                       Name:    Mark L. Withrow
                                       Title:   Executive Vice President


                                       OFFICER


                                        /s/ Larry N. Paulsen
                                       -------------------------------------
                                       Larry N. Paulsen