Allis Chalmers Energy Inc. Watch

from DEFA14A 4 pages Amendment Agreement (This “Agreement”), Dated as of October 1, 2010, to the Agreement and Plan of Merger, Dated as of August 12, 2010 (The “Merger Agreement”), by and Among Allis-Chalmers Energy Inc., a Delaware Corporation (The “Company”), Seawell Limited, a Bermuda Corporation (“Parent”), and Wellco Sub Company, a Delaware Corporation and a Wholly Owned Subsidiary of Parent (“Merger Sub”). Capitalized Terms Used but Not Defined Herein Shall Have the Meanings Ascribed Thereto in the Merger Agreement. Whereas the Parties Hereto Are the Parties to the Merger Agreement and Now Wish to Amend the Merger Agreement as of the Date Hereof; Now, Therefore, in Consideration of the Mutual Covenants Contained Herein and Intending to Be Legally Bound Hereby, the Parties Hereby Agree as Follows: Section 1. Amendment of the Merger Agreement. (A) Section 2.1(e) of the Merger Agreement Is Hereby Deleted in Its Entirety and the Following Is Hereby Substituted Therefor

from 8-K 4 pages Amendment Agreement (This “Agreement”), Dated as of October 1, 2010, to the Agreement and Plan of Merger, Dated as of August 12, 2010 (The “Merger Agreement”), by and Among Allis-Chalmers Energy Inc., a Delaware Corporation (The “Company”), Seawell Limited, a Bermuda Corporation (“Parent”), and Wellco Sub Company, a Delaware Corporation and a Wholly Owned Subsidiary of Parent (“Merger Sub”). Capitalized Terms Used but Not Defined Herein Shall Have the Meanings Ascribed Thereto in the Merger Agreement. Whereas the Parties Hereto Are the Parties to the Merger Agreement and Now Wish to Amend the Merger Agreement as of the Date Hereof; Now, Therefore, in Consideration of the Mutual Covenants Contained Herein and Intending to Be Legally Bound Hereby, the Parties Hereby Agree as Follows: Section 1. Amendment of the Merger Agreement. (A) Section 2.1(e) of the Merger Agreement Is Hereby Deleted in Its Entirety and the Following Is Hereby Substituted Therefor

from DEFA14A 109 pages Agreement and Plan of Merger by and Among Seawell Limited Wellco Sub Company and Allis-Chalmers Energy Inc. Dated as of August 12, 2010

from 8-K 109 pages Agreement and Plan of Merger by and Among Seawell Limited Wellco Sub Company and Allis-Chalmers Energy Inc. Dated as of August 12, 2010

from 10-K 96 pages Share Purchase Agreement Between Brazalta Resources Corp. and Allis-Chalmers Energy Inc. Dated as of December 19, 2008

from 425 14 pages First Amendment to the Agreement and Plan of Merger by and Among Allis-Chalmers Energy Inc., Bronco Drilling Company, Inc. and Elway Merger Sub, Inc. Dated as of June 1, 2008

from 425 14 pages First Amendment to the Agreement and Plan of Merger by and Among Allis-Chalmers Energy Inc., Bronco Drilling Company, Inc. and Elway Merger Sub, Inc. Dated as of June 1, 2008

from 8-K 14 pages First Amendment to the Agreement and Plan of Merger by and Among Allis-Chalmers Energy Inc., Bronco Drilling Company, Inc. and Elway Merger Sub, Inc. Dated as of June 1, 2008

from 8-K 100 pages Agreement and Plan of Merger by and Among Allis-Chalmers Energy Inc., Bronco Drilling Company, Inc. and Elway Merger Sub, Inc. Dated as of January 23, 2008

from 425 100 pages Agreement and Plan of Merger by and Among Allis-Chalmers Energy Inc., Bronco Drilling Company, Inc. and Elway Merger Sub, Inc. Dated as of January 23, 2008

from 425 100 pages Agreement and Plan of Merger by and Among Allis-Chalmers Energy Inc., Bronco Drilling Company, Inc. and Elway Merger Sub, Inc. Dated as of January 23, 2008

from 10-Q 97 pages Stock Purchase Agreement by and Among Bridas International Holdings Ltd., Bridas Central Company, Ltd., Associated Petroleum Investors Limited, and Allis-Chalmers Energy Inc. Dated as of April 27, 2006

from SC 13D ~5 pages Plan of reorganization, merger, acquisition or similar

from 10-K ~10 pages Plan of reorganization, merger, acquisition or similar

from 10-K ~20 pages Plan of reorganization, merger, acquisition or similar

from 10-K ~10 pages Plan of reorganization, merger, acquisition or similar

from 10-K ~20 pages Plan of reorganization, merger, acquisition or similar

from SC 13D/A ~5 pages Agreement and Proxy

from 8-K ~20 pages Agreement and Plan of Merger