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EXHIBIT 8.2

January [•], 2011

Allis-Chalmers Energy Inc.

5075 Westheimer, Suite 890

Houston, Texas 77056

Ladies and Gentlemen:

We have acted as counsel to Allis-Chalmers Energy Inc., a Delaware corporation (“Allis-Chalmers”), in connection with the Merger, as defined in the Agreement and Plan of Merger dated August 12, 2010, as amended (the “Merger Agreement”), entered into by and among Seawell Limited, a Bermuda corporation (“Seawell”), Wellco Sub Company, a Delaware corporation and a wholly-owned subsidiary of Seawell (“Merger Sub”), and Allis-Chalmers. This opinion is being delivered in connection with the Registration Statement on Form F-4 filed on December [•], 2010, as amended through the effective date thereof (the “Registration Statement”), with the Securities and Exchange Commission (the “Commission”) pursuant to the Securities Act of 1933, as amended (the “Securities Act”).

In arriving at the opinion expressed below, we have examined and relied upon, without independent investigation or verification, the accuracy and completeness, both initially and continuing as of the effective time of the Merger (the “Effective Time”), of the facts, information, representations, covenants, and agreements contained in the Merger Agreement, the Registration Statement, including the proxy statement/prospectus included therein and the documents incorporated by reference therein, and such other documents as we have deemed necessary or appropriate as a basis for the opinion set forth below. In addition, we have relied upon the accuracy and completeness, both initially and continuing as of the Effective Time, of certain statements and representations made by Seawell, Merger Sub, and Allis-Chalmers. For purposes of rendering our opinion, we have assumed that such statements and representations are, and will continue to be as of the Effective Time, true and correct without regard to any qualification as to knowledge or belief. Our opinion assumes and is conditioned upon, among other things, the initial and continuing accuracy and completeness of the facts, information, representations, covenants, and agreements set forth in the documents referred to above and the statements and representation made by Seawell, Merger Sub, and Allis-Chalmers. Any change in the accuracy or completeness of, or any variation or difference in, the facts, information, statements, representations, covenants, and agreements on which our opinion is based could affect our conclusions herein.

Allis-Chalmers Energy Inc.

January [•], 2011

Page 2

Our opinion is based on the Internal Revenue Code of 1986, as amended, Treasury regulations promulgated thereunder, judicial decisions, published positions of the Internal Revenue Service, and such other authorities as we have considered relevant, all as in effect on the date of this opinion and all of which are subject to change or different interpretations, possibly with retroactive effect. A change in any of the authorities upon which our opinion is based could affect our conclusions herein. There can be no assurance, moreover, that our opinion will be accepted by the Internal Revenue Service or, if challenged, by a court.

Based upon and subject to the foregoing, and subject to the qualifications, assumptions and limitations stated in the Registration Statement and set forth herein, we are of the opinion that, under current United States federal income tax law, although the discussion set forth in the Registration Statement under the caption “Material U.S. Federal Income Tax Consequences” does not purport to summarize all possible United States federal income tax consequences of the Merger applicable to U.S. holders, such discussion constitutes, in all material respects, a fair and accurate summary of the United States federal income tax consequences of the Merger that are anticipated to be material to U.S. holders, and, to he extent that it sets forth specific conclusions under United States Federal income tax law, except as otherwise provided therein, it represents our opinion.

Except as expressly set forth above, we express no opinion to any party as to any tax consequences, whether federal, state, local or foreign, of the Merger or of any transaction related to the Merger or contemplated by the Merger Agreement. Our opinion is rendered as of the date hereof and we assume no obligation to update or supplement this opinion or any matter related to this opinion to reflect any change of fact, circumstances, or law after such time as the Registration Statement is declared effective.

We hereby consent to the filing of this opinion as an exhibit to the Registration Statement and to the reference to our firm in the proxy statement/prospectus forming a part of the Registration Statement. In giving this consent, however, we do not hereby admit that we are within the category of persons whose consent is required under Section 7 of the Securities Act or the rules and regulations of the Commission issued thereunder.

Very truly yours,