1 EXHIBIT 23.1 CONSENT OF INDEPENDENT AUDITORS We consent to the incorporation by reference in the Registration Statement (Form S-8 No. 333-13261) pertaining to the UTI Energy Corp. 1993 Non-qualified Stock Option Plan, the First Amendment to Termination Agreement and Release, the UTI Energy Corp. Non-Employee Director Stock Option Plan of our report dated February 17, 1998, with respect to the consolidated financial statements and schedule of UTI Energy Corp. included in its Annual Report (Form 10-K) for the year ended December 31, 1997. Ernst & Young LLP Houston, Texas March 18, 1998