1 EXHIBIT 99.17 CONSENT OF PERSON ABOUT TO BECOME A DIRECTOR I hereby consent to being named as a person about to become a director to the Board of Directors of Pioneer Natural Resources Company, a Delaware corporation, in its Registration Statement on Form S-4 and any amendments thereto, filed with the Securities and Exchange Commission. /s/ Robert L. Stillwell ------------------------------ Robert L. Stillwell Dated: April 25, 1997