Filed by Seawell Limited. Pursuant to Rule 425

Under the Securities Act of 1933

And Deemed Filed Pursuant to Rule 14a-12

Under the Securities Exchange Act of 1934

Subject Company: Allis-Chalmers Energy Inc.

Commission File No. of Subject Company: 001-02199

This filing relates to the proposed merger of Wellco Sub Company, a wholly owned subsidiary of Seawell Limited, with Allis-Chalmers Energy Inc., pursuant to the terms of an Agreement and Plan of Merger, dated as of August 12, 2010, by and among Seawell Limited, Wellco Sub Company and Allis-Chalmers Energy Inc..

Forward-Looking Statements

This communication contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995.  Forward-looking statements are typically identified by words or phrases such as "will," "anticipate," "estimate," "expect," "project," "intend," "plan," "believe," "target," "forecast," and other words and terms of similar meaning.  These forward-looking statements involve a number of risks and uncertainties.  Seawell and Allis-Chalmers caution readers that any forward-looking statement is not a guarantee of future performance and that actual results could differ materially from those contained in the forward-looking statement.  Such forward-looking statements include, but are not limited to, statements about the benefits of the proposed merger involving Seawell and Allis-Chalmers, including future financial and operating results, Seawell's and Allis-Chalmers' plans, objectives, expectations and intentions, the expected timing of completion of the transaction, and other statements that are not historical facts.  Important factors that could cause actual results to differ materially from those indicated by such forward-looking statements are set forth in Allis-Chalmers’ filings with the Securities and Exchange Commission.  These include risks and uncertainties relating to: the ability to obtain the requisite Allis-Chalmers stockholder approval; the risk that Allis-Chalmers or Seawell may be unable to obtain governmental and regulatory approvals required for the merger, or required governmental and regulatory approvals may delay the merger or result in the imposition of conditions that could cause the parties to abandon the merger; the risk that a condition to closing of the merger may not be satisfied; the timing to consummate the proposed m erger; the risk that the businesses will not be integrated successfully; the risk that the cost savings and any other synergies from the transaction may not be fully realized or may take longer to realize than expected; disruption from the transaction making it more difficult to maintain relationships with customers, employees or suppliers; the diversion of management time on merger-related issues; general worldwide economic conditions and related uncertainties; and the effect of changes in governmental regulations.  Neither Seawell nor Allis-Chalmers undertakes any obligation to publicly update any forward-looking statement, whether as a result of new information, future events or otherwise.

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Additional Information and Where to Find It

This communication does not constitute an offer to sell or the solicitation of an offer to buy any securities or a solicitation of any vote or approval. The publication or distribution of this communication may, in some countries, be restricted by law or regulation. Accordingly, persons who come into possession of this document should inform themselves of and observe these restrictions. To the fullest extent permitted by applicable law, Seawell, Allis-Chalmers and their respective affiliates disclaim any responsibility or liability for the violation of such restrictions by any person. In connection with the proposed merger between Seawell and Allis-Chalmers, Seawell will file with the SEC a Registration Statement on Form F-4 that will include a proxy statement of Allis-Chalmers that also constitutes a prospectus of Seawel l.  Seawell and Allis-Chalmers will mail the proxy statement/prospectus to the Allis-Chalmers stockholders.  Seawell and Allis-Chalmers urge investors and stockholders to read the proxy statement / prospectus regarding the proposed merger when it becomes available, as well as other documents filed with the SEC, because they will contain important information. You may obtain copies of all documents filed with the SEC regarding this transaction, free of charge, at the SEC's website (www.sec.gov).  You may also obtain these documents, free of charge, from Seawell's website (www.seawellcorp.com) under the tab "Investors.”  You may also obtain these documents, free of charge, from Allis-Chalmers' website (www.alchenergy.com) under the tab "For Investors" and then under the heading "SEC Filings."

Participants In The Merger Solicitation

Seawell, Allis-Chalmers, and their respective directors, executive officers and certain other members of management and employees may be soliciting proxies from Allis-Chalmers stockholders in favor of the merger and related matters.  Information regarding the persons, who may, under the rules of the SEC, is deemed participants in the solicitation of Allis-Chalmers stockholders in connection with the proposed merger will be set forth in the proxy statement/prospectus when it is filed with the SEC.  You can find information about Allis-Chalmers' executive officers and directors in its definitive proxy statement filed with the SEC on April 30, 2010.  Additional information about Seawell's executive officers and directors and Allis-Chalmers' executive officers and directors can be found in the above-refere nced Registration Statement on Form F-4 when it becomes available.  You can obtain free copies of these documents from Seawell and Allis-Chalmers using the contact information above.

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SEAW - Confirms Intention to Pursue Listing on the Oslo Børs

Hamilton, Bermuda (September 23, 2010)

The Board of Directors of Seawell Limited has today approved the filing and pursuit of an application by the Company with the Oslo Stock Exchange for a listing of its shares on the Oslo Børs. The Company intends to file its application in the second half of October and pursue its approval at the meeting of the Oslo Børs Board of Directors November 24. If approved, the Company's shares would begin trading on the Oslo Børs shortly thereafter.

The Company has retained RS Platou Markets AS as manager (the "Manager") and Wiersholm, Mellbye & Bech, advokatfirma AS as legal adviser in connection with the listing process. The Manager has engaged Advokatfirmaet Schjødt DA and Ernst & Young as advisers.

Forward-Looking Statements

This communication contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995.  Forward-looking statements are typically identified by words or phrases such as "will," "anticipate," "estimate," "expect," "project," "intend," "plan," "believe," "target," "forecast," and other words and terms of similar meaning.  These forward-looking statements involve a number of risks and uncertainties.  Seawell and Allis-Chalmers caution readers that any forward-looking statement is not a guarantee of future performance and that actual results could differ materially from those contained in the forward-looking statement.  Such forward-looking statements include, but are not limited to, statements about the benefits of the proposed merger involving Seawell and Allis-Chalmers, including future financial and operating results, Seawell's and Allis-Chalmers' plans, objectives, expectations and intentions, the expected timing of completion of the transaction, and other statements that are not historical facts.  Important factors that could cause actual results to differ materially from those indicated by such forward-looking statements are set forth in Allis-Chalmers’ filings with the Securities and Exchange Commission.  These include risks and uncertainties relating to: the ability to obtain the requisite Allis-Chalmers stockholder approval; the risk that Allis-Chalmers or Seawell may be unable to obtain governmental and regulatory approvals required for the merger, or required governmental and regulatory approvals may delay the merger or result in the imposition of conditions that could cause the parties to abandon the merger; the risk that a condition to closing of the merger may not be satisfied; the timing to consummate the proposed m erger; the risk that the businesses will not be integrated successfully; the risk that the cost savings and any other synergies from the transaction may not be fully realized or may take longer to realize than expected; disruption from the transaction making it more difficult to maintain relationships with customers, employees or suppliers; the diversion of management time on merger-related issues; general worldwide economic conditions and related uncertainties; and the effect of changes in governmental regulations.  Neither Seawell nor Allis-Chalmers undertakes any obligation to publicly update any forward-looking statement, whether as a result of new information, future events or otherwise.

Additional Information and Where to Find It

This communication does not constitute an offer to sell or the solicitation of an offer to buy any securities or a solicitation of any vote or approval. The publication or distribution of this communication may, in some countries, be restricted by law or regulation. Accordingly, persons who come into possession of this document should inform themselves of and observe these restrictions. To the fullest extent permitted by applicable law, Seawell, Allis-Chalmers and their respective affiliates disclaim any responsibility or liability for the violation of such restrictions by any person. In connection with the proposed merger between Seawell and Allis-Chalmers, Seawell will file with the SEC a Registration Statement on Form F-4 that will include a proxy statement of Allis-Chalmers that also constitutes a prospectus of Seawel l.  Seawell and Allis-Chalmers will mail the proxy statement/prospectus to the Allis-Chalmers stockholders.  Seawell and Allis-Chalmers urge investors and stockholders to read the proxy statement / prospectus regarding the proposed merger when it becomes available, as well as other documents filed with the SEC, because they will contain important information. You may obtain copies of all documents filed with the SEC regarding this transaction, free of charge, at the SEC's website (www.sec.gov).  You may also obtain these documents, free of charge, from Seawell's website (www.seawellcorp.com) under the tab "Investors.”  You may also obtain these documents, free of charge, from Allis-Chalmers' website (www.alchenergy.com) under the tab "For Investors" and then under the heading "SEC Filings."

Participants In The Merger Solicitation

Seawell, Allis-Chalmers, and their respective directors, executive officers and certain other members of management and employees may be soliciting proxies from Allis-Chalmers stockholders in favor of the merger and related matters.  Information regarding the persons, who may, under the rules of the SEC, is deemed participants in the solicitation of Allis-Chalmers stockholders in connection with the proposed merger will be set forth in the proxy statement/prospectus when it is filed with the SEC.  You can find information about Allis-Chalmers' executive officers and directors in its definitive proxy statement filed with the SEC on April 30, 2010.  Additional information about Seawell's executive officers and directors and Allis-Chalmers' executive officers and directors can be found in the above-refere nced Registration Statement on Form F-4 when it becomes available.  You can obtain free copies of these documents from Seawell and Allis-Chalmers using the contact information above.