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                                                                    EXHIBIT 23.4

                CONSENT OF WILLIAMSON PETROLEUM CONSULTANTS, INC.

     As independent oil and gas consultants, Williamson Petroleum Consultants,
Inc. hereby consents to the inclusion of our summary report entitled "Letter
Report Including 46 Reports Prepared by Williamson Petroleum Consultants, Inc.
for Pioneer Natural Resources USA, Inc. to the Interests of Limited Partners or
Converted Limited Partners in Various Parker & Parsley Partnerships Managed by
Pioneer Natural Resources USA, Inc. Effective December 31, 2000, for Disclosure
to the Securities and Exchange Commission, Utilizing Aries Software, Williamson
Project 0.8839" and dated April 10, 2001, and to all references to our firm
included in or made a part of the Pioneer Natural Resources Company Registration
Statement on Form S-4 to be filed on April 17, 2001.


                                      /s/ Williamson Petroleum Consultants, Inc.

                                      WILLIAMSON PETROLEUM CONSULTANTS, INC.





Midland, Texas
April 17, 2001