<PAGE>

                 UNITED STATE SECURITIES AND EXCHANGE COMMISSION
                             Washington, D. C. 20549


                                   FORM 10-K/A
                                 AMENDMENT NO. 3



                                   (Mark One)

       [X] ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES
       EXCHANGE ACT OF 1934 FOR THE FISCAL YEAR ENDED DECEMBER 31, 2004 OR

     [ ] TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES
     EXCHANGE ACT OF 1934 FOR THE TRANSITION PERIOD FROM ________ TO ________

                          COMMISSION FILE NUMBER 1-2199


                           ALLIS-CHALMERS ENERGY INC.
                           --------------------------

             (Exact name of registrant as specified in its charter)


           DELAWARE                                               39-0126090
-------------------------------                              -------------------
(State or other jurisdiction of                               (I.R.S. Employer
incorporation or organization)                               Identification No.)

                5075 WESTHEIMER, SUITE 890, HOUSTON, TEXAS 77056
                ------------------------------------------------
               (Address of principal executive offices) (Zip code)

                                 (713) 369-0550
                                 --------------
               Registrant's telephone number, including area code

           SECURITIES REGISTERED PURSUANT TO SECTION 12(b) OF THE ACT:

          Title of Security:                      Name of Exchange:
Common Stock, par value $0.01 per share        American Stock Exchange

        SECURITIES REGISTERED PURSUANT TO SECTION 12(G) OF THE ACT: NONE

Indicate by check mark whether the registrant (1) has filed all reports required
to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during
the preceding 12 months (or for such shorter period that the registrant was
required to file such reports), and (2) has been subject to such filing
requirements for the past 90 days. Yes [X] No [ ]

Indicate by check mark if the disclosure of delinquent filers pursuant to Item
405 of Regulation S-K (ss.220.405 of this Chapter) is not contained herein, and
will not be contained, to the best of registrant's knowledge, in definitive
proxy or information statements incorporated by reference in Part III of this
Form 10-K or any amendment to this Form 10-K. [X]

Indicate by check mark whether the registrant is an accelerated filer (as
defined in Rule 12b-2 of the Act). Yes [ ] No [X]

The aggregate market value of the common equity held by non-affiliates of the
registrant, computed using the average of the closing price of the common stock
of $4.70 per share on April 12, 2005, as reported on the American Stock
Exchange, was approximately $15,064,562 (affiliates included for this
computation only: directors, executive officers and holders of more than 5% of
the registrant's common stock).

At April 12, 2005 there were 13,852,798 shares of common stock outstanding.

DOCUMENTS INCORPORATED BY REFERENCE:

Portions of the Allis-Chalmers Energy Inc. Proxy Statement prepared for the 2005
annual meeting of shareholders, pursuant to Regulation 14A, are incorporated by
reference into Part III of this Report.

<PAGE>

                             2004 FORM 10-K CONTENTS
                             -----------------------


                                INTRODUCTORY NOTE


Allis-Chalmers Energy Inc. is filing this Amendment No. 3 to the Company's
Annual report on Form 10-K for the year ended December 31, 2004 to revise the
disclosure relating to changes in internal control over financial reporting.


 ITEM                                                                       PAGE
 ----                                                                       ----

                                     PART II

9A. Controls and Procedures................................................   3


                                     PART IV

15.  Exhibits, Financial Statement Schedules, and Reports on Form 8-K......   5


Signatures and Certifications..............................................   6



Unaffected items have not been repeated in this Amendment No. 3.

PLEASE NOTE THAT THE INFORMATION CONTAINED IN THIS AMENDMENT NO. 3, INCLUDING
THE FINANCIAL STATEMENTS AND THE NOTES THERETO, DOES NOT REFLECT EVENTS
OCCURRING AFTER THE ORIGINAL FILING DATE. SUCH EVENTS INCLUDE, AMONG OTHERS, THE
EVENTS DESCRIBED IN OUR QUARTERLY REPORTS ON FORM 10-Q FOR THE PERIODS ENDED
MARCH 31, 2005 AND JUNE 30, 2005 AND THE EVENTS DESCRIBED IN OUR CURRENT REPORTS
ON FORM 8-K FILED SUBSEQUENT TO THE ORIGINAL FILING DATE. FOR A DESCRIPTION OF
THESE EVENTS, PLEASE READ OUR EXCHANGE ACT REPORTS FILED SINCE THE ORIGINAL
FILING DATE INCLUDING ALL AMENDMENTS THERETO.



                                       2
<PAGE>

ITEM 9A.  CONTROLS AND PROCEDURES.

DISCLOSURE CONTROLS AND PROCEDURES. We maintain disclosure controls and
procedures that are designed to ensure that information required to be disclosed
in our reports under the Securities Exchange Act of 1934, as amended, are
recorded, processed, summarized and reported within the time periods specified
in the SEC's rules and forms, and that such information is accumulated and
communicated to management, including our chief executive officer and chief
financial officer, as appropriate, to allow timely decisions regarding required
disclosures. Our internal control system is designed to provide reasonable
assurance regarding the preparation and fair presentation of published financial
statements. All internal control systems are designed based in part upon certain
assumptions about the likelihood of future events, and, no matter how well
designed, have inherent limitations. Therefore, even those systems determined to
be effective can provide only reasonable assurance with respect to financial
statement preparation and presentation and may not prevent or detect all
misstatements.

Management, including our chief executive officer and our chief financial
officer has evaluated the effectiveness of our "disclosure controls and
procedures" (as defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) as of the
end of the period covered by this Report (the "Evaluation Date"). Management has
concluded that, as of the Evaluation Date, due to the deficiencies described
below, our controls and procedures over financial reporting were not effective
to enable us to record, process, summarize, and report information required to
be included in our SEC filings within the required time period, and to ensure
that such information is accumulated and communicated to our management,
including our chief executive officer and chief financial accounting officer, to
allow timely decisions regarding required disclosure. As described below, we are
taking steps to remediate the deficiencies in our control over the financial
reporting process.

On August 4, 2005, our Board of Directors, upon the recommendation of the Audit
Committee of our Board of Directors, concluded that our previously issued
financial statements for the periods from July 1, 2003 through March 31, 2005,
were required to be restated to correct the understatement of net income per
share which resulted from a miscalculation of the number of basic and diluted
shares outstanding on a weighted average basis in accordance with SFAS No. 128,
EARNINGS PER SHARE. The deficiency resulted from errors discovered by our
independent accountants on August 1, 2005, while reviewing our financial
statements for the quarter ended June 30, 2005. The major components of the
errors were as follows:

         o        For all periods involved we had not applied the treasury stock
                  method of accounting for options and warrants as prescribed in
                  SFAS No. 128. Specifically, we overstated diluted shares
                  outstanding because we failed to reduce diluted shares
                  outstanding by the number of shares that could be purchased
                  with the proceeds to us from the exercise of dilutive warrants
                  and options.
         o        In 2003 and 2004, we overstated diluted shares by not
                  correctly calculating the number of common shares into which
                  our preferred stock was convertible; by not applying the "if
                  converted" method of calculating diluted net earnings which
                  requires that dividends actually paid on preferred stock be
                  added to net income attributed to common shares in calculating
                  diluted earnings per common share; and by continuing to report
                  the preferred shares as dilutive after the preferred shares
                  were converted to common stock on April 2, 2004.
         o        During the third quarter of 2004, we misstated the number of
                  common shares outstanding on a weighted average basis due to a
                  mathematical error in calculating the number of days certain
                  shares issued during the quarter were outstanding.

In addition, in March 2005, we restated our financial statements for the year
ended December 31, 2003 and for the three quarters ended September 30, 2004,
relating to our acquisition of a 55% interest in our AirComp, LLC subsidiary in
2003. We originally accounted for the formation of AirComp as a joint venture,
but in February 2005, determined that the transaction should have been accounted
for using purchase accounting pursuant to SFAS No. 141, BUSINESS COMBINATIONS
and accounting for the sale of an interest in a subsidiary in accordance with
SAB No. 51.

We have restated our financial statements as set forth in Note 2 to the
Consolidated Financial Statements contained in Part II, Item 8.


                                       3
<PAGE>


Public Company Accounting Oversight Board ("PCAOB") Auditing Standard No. 2
identifies a number of circumstances that, because of their likely significant
negative effect on internal control over financial reporting, are to be regarded
as at least significant deficiencies as well as strong indicators that a
material weakness exists, including the restatement of previously-issued
financial statements to reflect the correction of a misstatement. Management
evaluated the impact of the restatement of our previously-issued financial
statements on our assessment of our system of internal control and has concluded
that the restatements resulted from the lack of sufficient experienced
accounting personnel resulting in a lack of effective control over the financial
reporting process.

We have implemented a number of actions that we believe address the deficiencies
in our financial reporting process, including the following:

         o        The addition of experienced accounting personnel with
                  appropriate experience and qualifications to perform quality
                  review procedures and to satisfy our financial reporting
                  obligation. During August 2004, we hired a new chief financial
                  officer and in October of 2004 we hired a full-time general
                  counsel. In March 2005, we hired a certified public accountant
                  as our financial reporting manager and in July 2005 we hired
                  as chief accounting officer a certified public accountant who
                  has significant prior experience as a chief accounting officer
                  of a publicly traded company.
         o        In the fourth quarter of 2004, we engaged an independent
                  internal controls consulting firm which is in the process of
                  documenting, analyzing, identifying and correcting weaknesses
                  and testing our internal controls and procedures, including
                  our controls over internal financial reporting.
         o        Our audit committee dismissed our prior independent auditors
                  in October 2004 and engaged new independent auditors who we
                  believe have greater experience with publicly traded
                  companies.
         o        We are in the process of implementing new accounting software
                  to facilitate timely and accurate reporting.

CHANGE IN INTERNAL CONTROL OVER FINANCIAL REPORTING.


The following changes were made in our internal control over financial reporting
(as such term is defined in Rules 13a-15(f) and 15d-15(f) under the Exchange
Act) that occurred during the period covered by this report that have materially
affected, or are reasonably likely to materially affect, our internal control
over financial reporting:


         o        In August 2004, we hired a new chief financial officer.

         o        In October 2004, we hired full-time general counsel

         o        In October 2004, we dismissed out prior independent auditors
                  and engaged new independent auditors who we believe have
                  greater experience serving publicly traded companies.

         o        In the fourth quarter of 2004, we engaged an independent
                  internal controls consulting firm which is in the process of
                  documenting, analyzing, identifying and testing internal
                  control. In addition, we are improving our financial
                  accounting systems by implementing a more integrated
                  accounting software solution.


                                       4
<PAGE>

                                     PART IV


ITEM 15.  EXHIBITS, FINANCIAL STATEMENT SCHEDULES, AND REPORTS ON FORM 8-K

(c) EXHIBITS


The exhibits listed on the Exhibit Index located at Page 7 of this Annual
Report are filed as part of this Form 10K/A.



                                       5
<PAGE>

                                   SIGNATURES


Pursuant to the requirements of Section 13 or 15(d) of the Securities Exchange
Act of 1934, as amended, the registrant has duly caused this report to be signed
on its behalf by the undersigned, thereunto duly authorized on August 17, 2005.



                                         /S/ MUNAWAR H. HIDAYATALLAH
                                         ------------------------------------
                                         MUNAWAR H. HIDAYATALLAH
                                         CHIEF EXECUTIVE OFFICER AND CHAIRMAN


                                       6
<PAGE>

                                  EXHIBIT INDEX


EXHIBIT                            DESCRIPTION

2.1       First Amended Disclosure Statement pursuant to Section 1125 of the
Bankruptcy Code, dated September 14, 1988, which includes the First Amended and
Restated Joint Plan of Reorganization dated September 14, 1988 (incorporated by
reference to Registrant's Current Report on Form 8-K dated December 1, 1988).

2.2       Agreement and Plan of Merger dated as of May 9, 2001 by and among
Registrant, Allis-Chalmers Acquisition Corp. and OilQuip Rentals, Inc.
(incorporated by reference to Registrant's Current Report on Form 8-K filed May
15, 2001).

2.3       Stock Purchase Agreement dated February 1, 2002 by and between
Registrant and Jens H. Mortensen, Jr. (incorporated by reference to Registrant's
Current Report on Form 8-K filed February 21, 2002).

2.4       Shareholders Agreement dated February 1, 2002 by and among Jens'
Oilfield Service, Inc., a Texas corporation, Jens H. Mortensen, Jr., and
Registrant (incorporated by reference to Registrant's Annual Report on Form 10-K
for the year ended December 31, 2001).

2.5       Stock Purchase Agreement dated February 1, 2002 by and among
Registrant, Energy Spectrum Partners LP, and Strata Directional Technology, Inc.
(incorporated by reference to Registrant's Annual Report on Form 10-K for the
year ended December 31, 2001).

2.6       Joint Venture Agreement dated June 27, 2003 by and between Mountain
Compressed Air, Inc. and M-I L.L.C. (incorporated by reference to Registrant's
Current Report on Form 8-K filed July 16, 2003).

3.1       Amended and Restated Certificate of Incorporation of Registrant
(incorporated by reference to Registrant's Annual Report on Form 10-K for the
year ended December 31, 2001).

3.2       Certificate of Designation, Preferences and Rights of the SERIES A 10%
CUMULATIVE CONVERTIBLE PREFERRED STOCK ($.01 Par Value) of Registrant
(incorporated by reference to Registrant's Current Report on Form 8-K filed
February 21, 2002).

3.3       Amended and Restated By-laws of Registrant.

3.4       Certificate of Amendment of Certificate of Incorporation filed with
the Delaware Secretary of State on June 9, 2004 (incorporated by reference to
the Registrant's Quarterly Report on Form 10-Q for the quarter ended June 30,
2004).

3.5       Certificate of Amendment of Certificate of Incorporation filed with
the Delaware Secretary of State on January 5, 2005 (incorporated by reference to
the Registrant's Current Report on Form 8-K filed January 11, 2005).

4.1       Specimen Stock Certificate of Common Stock of Registrant.

4.2       Registration Rights Agreement dated as of March 31, 1999, by and
between Allis-Chalmers Corporation and the Pension Benefit Guaranty Corporation
(incorporated by reference to the Registrant's Quarterly Report on Form 10-Q for
the quarter ended June 30, 1999).

4.3       Option Agreement dated October 15, 2001 by and between Registrant and
Leonard Toboroff (incorporated by reference to Registrant's Quarterly Report on
Form 10-Q for the quarter ended September 30,2001).

4.4       Warrant Purchase Agreement dated February 1, 2002 by and between
Allis-Chalmers Corporation and Wells Fargo Energy Capital, Inc., including form
of warrant (incorporated by reference to the Registrant's Current Report on Form
8-K filed February 21, 2002).

4.5       Warrant Purchase Agreement dated February 1, 2002 by and between
Allis-Chalmers Corporation and Energy Spectrum Partners LP, including form of
warrant (incorporated by reference to the Registrant's Current Report on Form
8-K filed February 21, 2002).


                                       7
<PAGE>

*4.6      2003 Incentive Stock Plan (incorporated by reference to Registrant's
Definitive Proxy Statement on Schedule 14A filed December 9, 2004).

*4.7      Form of Option Certificate issued pursuant to 2003 Incentive Stock
Plan (incorporated by reference to Registrant's Annual Report on Form 10-K for
the year ended December 31, 2002).

4.8       Warrant dated March 1, 2004, issued to Morgan Joseph & Co., Inc.
(incorporated by reference to the Registration Statement on Form S-1
(Registration No. 118916) filed on September 10, 2004).

4.9       Form of warrant issued to Investors pursuant to Stock and Warrant
Purchase Agreement dated April 2, 2004 by and among Registrant and Donald Engel,
Christopher Engel The Engel Defined Benefit plan, RER Corp. and Leonard Toboroff
(incorporated by reference to Registrant's Quarterly Report on Form 10-Q for the
quarter ended June 30, 2004).

4.10      Registration Rights Agreement dated April 2, 2004 by and between
Registrant and the Stockholder signatories thereto (incorporated by reference to
Registrant's Quarterly Report on Form 10-Q for the quarter ended June 30, 2004).

4.11      Warrant dated May 19, 2004, issued to Jeffrey R. Freedman
(incorporated by reference to the Registration Statement on Form S-1
(Registration No. 118916) filed on September 10, 2004).



9.1       Shareholders Agreement dated February 1, 2002 by and among Registrant
and the stockholder and warrant holder signatories thereto (incorporated by
reference to Registrant's Annual Report on Form 10-K for the year ended December
31, 2001).

9.2       Stockholders Agreement dated April 2, 2004, by and among Registrant
and the Stockholder signatories thereto. (incorporated by reference to the
registrant's Annual Report in Form 10-K for the year ended December 31, 2003).

10.1      Amended and Restated Retiree Health Trust Agreement dated September
14, 1988 by and between Registrant and Wells Fargo Bank (incorporated by
reference to Exhibit C-1 of the First Amended and Restated Joint Plan of
Reorganization dated September 14, 1988 included in Registrant's Current Report
on Form 8-K dated December 1, 1988).

10.2      Amended and Restated Retiree Health Trust Agreement dated September
18, 1988 by and between Registrant and Firstar Trust Company (incorporated by
reference to Exhibit C-2 of the First Amended and Restated Joint Plan of
Reorganization dated September 14, 1988 included in Registrant's Current Report
on Form 8-K dated December 1, 1988).

10.3      Reorganization Trust Agreement dated September 14, 1988 by and
between Registrant and John T. Grigsby, Jr., Trustee (incorporated by reference
to Exhibit D of the First Amended and Restated Joint Plan of Reorganization
dated September 14, 1988 included in Registrant's Current Report on Form 8-K
dated December 1, 1988).

10.4      Product Liability Trust Agreement dated September 14, 1988 by and
between Registrant and Bruce W. Strausberg, Trustee (incorporated by reference
to Exhibit E of the First Amended and Restated Joint Plan of Reorganization
dated September 14, 1988 included in Registrant's Current Report on Form 8-K
dated December 1, 1988).

*10.5     Allis-Chalmers Savings Plan (incorporated by reference to
Registrant's Annual Report on Form 10-K for the year ended December 31, 1988).

*10.6     Allis-Chalmers Consolidated Pension Plan (incorporated by reference
to Registrant's Annual Report on Form 10-K for the year ended December 31,
1988).

10.7      Agreement dated as of March 31, 1999 by and between Registrant and
the Pension Benefit Guaranty Corporation (incorporated by reference to
Registrant's Quarterly Report on Form 10-Q for the quarter ended June 30, 1999).

10.8      Letter Agreement dated May 9, 2001 by and between Registrant and the
Pension Benefit Guarantee Corporation (incorporated by reference to Registrant's
Quarterly Report on Form 10-Q filed on May 15, 2002).


                                       8
<PAGE>

10.9      Termination Agreement dated May 9, 2001 by and between Registrant,
the Pension Benefit Guarantee Corporation and others (incorporated by reference
to Registrant's Current Report on Form 8-K filed on May 15, 2002).

*10.10    Employment Agreement dated February 7, 2001 by and between OilQuip
Rentals, Inc. and Munawar H. Hidayatallah (incorporated by reference to the
Company's Report on Form 10-K for the year ended December 31, 2001).

*10.11    Option Agreement dated October 15, 2001 by and between Registrant
and Leonard Toboroff (incorporated by reference to Registrant's Quarterly Report
on Form 10-Q for the quarter ended September 30, 2001).

10.12     Credit and Security Agreement dated February 1, 2002 by and between
Jens' Oilfield Service, Inc. and Wells Fargo Credit, Inc. (incorporated by
reference to Registrant's Current Report on Form 8-K filed February 21, 2002).

10.13     Amended and Restated Credit and Security Agreement dated February 1,
2002 by and between Strata Directional Technology, Inc. and Wells Fargo Credit,
Inc. (incorporated by reference to Registrant's Current Report on Form 8-K filed
February 21, 2002).

10.14     Credit Agreement dated February 1, 2002 by and between Registrant
and Wells Fargo Energy Capital, Inc. (incorporated by reference to Registrant's
Current Report on Form 8-K filed February 21, 2002).

10.15     Warrant Purchase Agreement dated February 1, 2002 by and between
Registrant and Wells Fargo Energy Capital, Inc. (incorporated by reference to
Registrant's Current Report on Form 8-K filed February 21, 2002).

*10.16    Employment Agreement dated February 1, 2002 by Jens' Oilfield
Service, Inc. and Jens H. Mortensen, Jr. (incorporated by reference to
Registrant's Current Report on Form 8-K filed February 21, 2002).

10.17     Forbearance Agreement dated January 17, 2003 by and between Mountain
Compressed Air, Inc., and Wells Fargo Equipment Finance, Inc. (incorporated by
reference to Registrant's Annual Report on Form 10-K for the period ended
December 31, 2002).

10.18     Forbearance Agreement and Second Amendment to Amended and Restated
Credit Agreement dated March 21, 2003, by and between Strata Directional
Technology, Inc., and Wells Fargo Credit, Inc. (incorporated by reference to
Registrant's Annual Report on Form 10-K for the period ended December 31, 2002).

10.19     Forbearance Agreement and First Amendment to Credit Agreement dated
March 21, 2003 by and between Jens' Oilfield Service, Inc. and Wells Fargo
Credit, Inc. (incorporated by reference to Registrant's Annual Report on Form
10-K for the period ended December 31, 2002).

10.20     Credit and Security Agreement by and between AirComp, L.L.C. and
Wells Fargo Bank Texas NA, including Term Note, Revolving Line of Credit, and
Delayed Draw Term Note, each dated as of June 27, 2003 (incorporated by
reference to Registrant's Current Report on Form 8-K filed July 16, 2003).

10.21     Security Agreement by and between AirComp, L.L.C. and Wells Fargo
Bank Texas NA, dated as of June 27, 2003 (incorporated by reference to
Registrant's Current Report on Form 8-K dated July 16, 2003).

*10.22    Employment Agreement dated July 1, 2003 by and between AirComp,
L.L.C. and Terry Keane (incorporated by reference to Registrant's Current Report
on Form 8-K filed July 16, 2003).

10.23     Second Amendment to Credit Agreement dated September 30, 2003 by and
between Jens' Oilfield Service, Inc. and Wells Fargo Credit Inc. (incorporated
by reference to Registrant's Quarterly Report on Form 10-Q for the period ended
September 30, 2003).

10.24     Third Amendment to Credit Agreement dated September, 2003 by and
between Strata Directional Technology, Inc., and Wells Fargo Credit Inc.
(incorporated by reference to Registrant's Quarterly Report on Form 10-Q for the
period ended September 30, 2003).


                                       9
<PAGE>

10.25     First Amendment to Credit Agreement dated October 1, 2003 by and
between Registrant and Wells Fargo Energy Capital Inc. (incorporated by
reference to Registrant's Quarterly Report on Form 10-Q for the period ended
September 30, 2003).

10.26     First Amendment to Credit Agreement dated as of December 31, 2003
between AirComp, L.L.C. and Wells Fargo Bank, NA (incorporated by reference to
Registrant's Quarterly Report on Form 10-Q for the quarter ended June 30, 2004).

10.27     Fourth Amendment to Credit Agreement dated as of January 30, 2004 by
and between Strata Directional Technology, Inc., and Wells Fargo Credit Inc.
(incorporated by reference to Registrant's Quarterly Report on Form 10-Q for the
quarter ended June 30, 2004).

10.28     Letter Agreement dated February 13, 2004 by and between Registrant
and Morgan Joseph & Co., Inc. (incorporated by reference to the Registration
Statement on Form S-1 (Registration No. 118916) filed on September 10, 2004).

*10.29    Employment Agreement dated as of April 1, 2004 between Registrant
and Munawar H. Hidayatallah (incorporated by reference to Registrant's Quarterly
Report on Form 10-Q for the quarter ended June 30, 2004).

*10.30    Employment Agreement dated as of April 1, 2004 between Registrant
and David Wilde (incorporated by reference to Registrant's Quarterly Report on
Form 10-Q for the quarter ended June 30, 2004).

10.31     Stock and Warrant Purchase Agreement dated April 2, 2004 by and
among Registrant and Donald Engel, Christopher Engel, the Engel Defined Benefit
Plan, RER Corp. and Leonard Toboroff (incorporated by reference to Registrant's
Quarterly Report on Form 10-Q for the quarter ended June 30, 2004).

10.32     Preferred Stock Conversion Agreement dated April 2, 2004 by and
between Registrant and Energy Spectrum Partners LP (incorporated by reference to
Registrant's Quarterly Report on Form 10-Q for the quarter ended June 30, 2004).

10.33     Second Amendment to Credit Agreement dated as of April 2, 2004
between AirComp, L.L.C. and Wells Fargo Bank, NA (incorporated by reference to
Registrant's Quarterly Report on Form 10-Q for the quarter ended June 30, 2004).

10.34     Amendment to Credit Agreement by and between Registrant and Wells
Fargo Energy Capital dated April 2, 2004 (incorporated by reference to
Registrant's Quarterly Report on Form 10-Q for the quarter ended June 30, 2004).

10.35     Fifth Amendment to Credit Agreement dated as of April 6, 2004 by and
between Strata Directional Technology, Inc., and Wells Fargo Credit Inc.
(incorporated by reference to Registrant's Quarterly Report on Form 10-Q for the
quarter ended June 30, 2004).

10.36     Third Amendment to Credit Agreement dated as of April 6, 2004 by and
between Jens' Oilfield Service, Inc. and Wells Fargo Credit Inc. (incorporated
by reference to Registrant's Quarterly Report on Form 10-Q for the quarter ended
June 30, 2004).

10.37     Letter Agreement dated June 8, 2004 by and between the Registrant
and Morgan Keegan & Company, Inc. (incorporated by reference to the Registration
Statement on Form S-1 (Registration No. 118916) filed on September 10, 2004).

*10.38    Employment Agreement dated July 26, 2004 by and between the
Registrant and Victor M. Perez (incorporated by reference to the Registration
Statement on Form S-1 (Registration No. 118916) filed on September 10, 2004).

10.39     Stock Purchase Agreement dated August 10, 2004 (incorporated by
reference to the Registration Statement on Form S-1 (Registration No. 118916)
filed on September 10, 2004).

10.40     Amendment to Stock Purchase Agreement dated August 10, 2004
(incorporated by reference to the Registration Statement on Form S-1
(Registration No. 118916) filed on September 10, 2004).

10.41     Letter Agreement relating to Stock Purchase Agreement dated August
5, 2004 (incorporated by reference to the Registration Statement on Form S-1
(Registration No. 118916) filed on September 10, 2004).


                                       10
<PAGE>

10.42     Addendum to Stock Purchase Agreement dated September 24, 2004
(incorporated by reference to Registrant's Current Report on Form 8-K filed on
September 30, 2004).

10.43     Stock Purchase Agreement dated September 24, 2004 (incorporated by
reference to Registrant's Current Report on Form 8-K filed on September 30,
2004).

10.44     Amendment to Stock Purchase Agreement (undated) (incorporated by
reference to Registrant's Current Report on Form 8-K filed on September 30,
2004).

10.45     Side Letter dated August 5, 2004, related to Stock Purchase
Agreement (incorporated by reference to Registrant's Current Report on Form 8-K
filed on September 30, 2004).

10.46     Agreement and Plan of Merger dated September 30, 2004 (incorporated
by reference to Registrant's Current Report on Form 8-K filed on October 6,
2004).

10.47     Employment Agreement dated October 11, 2004, between the Registrant
and Theodore F. Pound III (incorporated by reference to Registrant's Current
Report on Form 8-K filed on October 15, 2004).

10.48     Asset Purchase Agreement dated November 10, 2004 by and among
AIRCOMP L.L.C., a Delaware limited liability company, DIAMOND AIR DRILLING
SERVICES, INC., a Texas corporation, and MARQUIS BIT CO., L.L.C., a New Mexico
limited liability company, GREG HAWLEY and TAMMY HAWLEY, residents of Texas and
CLAY WILSON and LINDA WILSON, residents of New Mexico (incorporated by reference
to the Current Report on Form 8-K filed on November 15, 2004).

10.49     Amended and Restated Credit Agreement dated as of December 7, 2004,
between AirComp, L.L.C. and Wells Fargo Bank, NA (incorporated by reference to
Registrant's Current Report on Form 8-K filed on December 13, 2004).

10.50     Purchase Agreement and related Agreements by and among
Allis-Chalmers Corporation, Chevron USA, Inc., Dale Redman and others dated
December 10, 2004 (incorporated by reference to the Current Report on Form 8-K
filed on December 16, 2004).

14.1      Code of Ethics (incorporated by reference to the Form 8-K filed on
December 1, 2004.

16.1      Letter from Gordon Hughes & Banks LLP dated October 5, 2004, to the
Securities and Exchange Commission (incorporated by reference to Registrant's
Current Report on Form 8-K filed on October 6, 2004).

21.1      Subsidiaries of Registrant (filed with the original filing of this
report).

31.1      Certification of Chief Executive Officer pursuant to Section 302 of
the Sarbanes-Oxley Act of 2002.

31.2      Certification of Chief Financial Officer pursuant to Section 302 of
the Sarbanes-Oxley Act of 2002.

32.1      Certification of the Chief Executive Officer and Chief Financial
Officer pursuant to 18 U.S.C. 1350, as adopted pursuant to Section 906 of the
Sarbanes-Oxley Act of 2002.

*         Compensation Plan or Agreement


                                       11