AMENDMENT TO EXECUTIVE EMPLOYMENT AGREEMENT

Exhibit 10.17

AMENDMENT
TO
EXECUTIVE EMPLOYMENT AGREEMENT

      WHEREAS , Strata Directional Technology LLC (the “Company”) and David K. Bryan (the “Executive”) entered into that certain Executive Employment Agreement dated as of July 1, 2007, (the “Agreement”); and

      WHEREAS , the Company and the Executive desire to amend the Agreement to comply with Internal Revenue Code (“Code”) Section 409A and regulations issued thereunder;

      NOW, THEREFORE , the Agreement is hereby amended, effective as of the original effective date of the Agreement, as follows:

1. The second sentence in Section 5(b) of the Agreement is hereby amended and restated as follows:

     “Such bonus shall be paid annually within 30 days following Allis-Chalmers’ release of its audited financial statements for each year during the term hereof, but in no event earlier than January 1 of, and no later than December 31 of, the calendar year following the calendar year with respect to which such bonus is earned.”

2. A new Section 7(c) is hereby added to the Agreement as follows:

     “(c) Section 409A Limits on Payment