Amendment No. 7, dated as of December 12, 2008, among Mariner Energy, Inc. and Mariner Energy Resources, Inc., as Borrowers, the Lenders (as defined in the Amended and Restated Credit Agreement, dated as of March 2, 2006, among Mariner Energy, Inc. and Mariner Energy Resources, Inc., as Borrowers, the Lenders party thereto from time to time, as Lenders, and Union Bank of California, N.A., as Administrative Agent and as Issuing Lender, as amended), and Union Bank of California, N.A., as Administrative Agent for such Lenders and as Issuing Lender for such Lenders

Exhibit 4.1

AMENDMENT NO. 7

     This Amendment No. 7 (“Amendment”) dated as of December 12, 2008 (“Effective Date”) is among Mariner Energy, Inc., a Delaware corporation (the “Parent”), Mariner Energy Resources, Inc., a Delaware corporation (“Mariner Energy Resources” and together with the Parent, the “Borrowers”, each a “Borrower”), the Lenders (as defined in the Credit Agreement described below), and Union Bank of California, N.A., as administrative agent (in such capacity, the “Administrative Agent”) and as issuing lender (in such capacity, the “Issuing Lender”).

RECITALS

     A. The Borrowers, the Lenders, the Issuing Lender and the Administrative Agent are parties to the Amended and Restated Credit Agreement dated as of March 2, 2006, as amended by Amendment No. 1 and Consent dated as of April 7, 2006, Amendment No. 2 dated as of October 13, 2006, Amendment No. 3 and Consent dated as of April 23, 2007, Amendment No. 4 dated as of August 24, 2007, Amendment No. 5 and Agreement dated as of January 31, 2008, and Master Assignment, Agreement and Amendment No. 6 dated as of June 2, 2008 (as so amended and as the same may be further amended, restated, supplemented or otherwise modified from time to time, the “Credit Agreement”).

     B. The Borrowers, the Administrative Agent and the Lenders wish to, subject to the terms and conditions of this Amendment, (i) redetermine the amount of the Borrowing Base, and (ii) make certain amendments to the Credit Agreement as provided herein.

     THEREFORE, the Borrowers, the subsidiaries of the Borrowers signatory hereto (the “Guarantors”), the Lenders, the Issuing Lender and the Administrative Agent hereby agree as follows:

ARTICLE I.
DEFINITIONS

     Section 1.01 Terms Defined Above. As used in this Amendment, each of the terms defined in the opening paragraph and the Recitals above shall have the meanings assigned to such terms therein.

     Section 1.02 Terms Defined in the Credit Agreement. Each term defined in the Credit Agreement and used herein without definition shall have the meaning assigned to such term in the Credit Agreement, unless expressly provided to the contrary.

     Section 1.03 Other Definitional Provisions. The words “hereby”, “herein”, “hereinafter”, “hereof”, “hereto” and “hereunder” when used in this Amendment shall refer to this Amendment as a whole and not to any particular Article, Section, subsection or provision of this Amendment. Article, Section, subsection and Exhibit references herein are to such Articles, Sections, subsections and Exhibits of this Amendment unless otherwise specified. All titles or headings to Articles, Sections, subsections or other divisions of this Amendment or the exhibits hereto, if any, are only for the convenience of the parties and shall not be construed to have any effect or meaning with respect to the other content of such Articles, Sections, subsections, other divisions or exhibits, such other content being controlling as the agreement among the parties

hereto. Whenever the context requires, reference herein made to the single number shall be understood to include the plural; and likewise, the plural shall be understood to include the singular. Words denoting sex shall be construed to include the masculine, feminine and neuter, when such construction is appropriate; and specific enumeration shall not exclude the general but shall be construed as cumulative. Definitions of terms defined in the singular or plural shall be equally applicable to the plural or singular, as the case may be, unless otherwise indicated.

ARTICLE II.
BORROWING BASE

     Section 2.01 Redetermination of Borrowing Base. Subject to the terms of this Amendment, the parties hereto agree that, as of the Effective Date, the Borrowing Base shall be equal to $850,000,000 and such Borrowing Base shall remain in effect at such amount until the Borrowing Base is redetermined in accordance with the Credit Agreement.

ARTICLE III.
AMENDMENTS TO CREDIT AGREEMENT

     Section 3.01 Section 2.02. Section 2.02(b)(i) of the Credit Agreement is hereby amended by adding the following sentence to the end thereof:

Notwithstanding the foregoing, the Borrowing Base redetermination scheduled to take place in the spring of 2009 shall take place in February 2009, using an Independent Engineering Report dated effective as of December 31, 2008, which the Borrower Representative shall deliver to the Administrative Agent and each of the Lenders on or before January 31, 2009.

     Section 3.02 Section 8.01. The first sentence of Section 8.01 of the Credit Agreement is hereby deleted in its entirety and replaced with the following:

The Obligations of each Borrower are joint and several and absolute and unconditional irrespective of the value, genuineness, validity, regularity or enforceability of the Obligations of the other Borrower (collectively, the “Other Borrower Obligations”), or any substitution, release or exchange of any other guarantee of or security for any of the Other Borrower Obligations, and, to the fullest extent permitted by applicable law, irrespective of any other circumstance whatsoever which might otherwise constitute a legal or equitable discharge or defense of a surety or guarantor. The Obligations of each Borrower shall be absolute and unconditional under any and all circumstances, and the Borrowers shall be jointly and severally liable for the Obligations.

ARTICLE IV.
REPRESENTATIONS AND WARRANTIES

     Section 4.01 Borrowers Representations and Warranties. Each of the Borrowers represents and warrants that: (a) its representations and warranties contained in Article IV of the Credit Agreement and its representations and warranties contained in the Security Instruments, the Guaranties, and each of the other Loan Documents to which it is a party are true and correct

in all material respects on and as of the Effective Date, after giving effect to the terms of this Amendment, as though made on and as of such date, except those representations and warranties that speak of a certain date, which representations and warranties remain true and correct as of such certain date; (b) no Default has occurred and is continuing; (c) the execution, delivery and performance of this Amendment are within the corporate power and authority of each of the Borrowers and have been duly authorized by appropriate corporate action and proceedings; (d) this Amendment constitutes the legal, valid, and binding obligation of each of the Borrowers enforceable in accordance with its terms, except as limited by applicable bankruptcy, insolvency, reorganization, moratorium, or similar laws affecting the rights of creditors generally and general principles of equity; (e) there are no governmental or other third party consents, licenses or approvals required in connection with the execution, delivery, performance, validity and enforceability of this Amendment; and (f) the Liens under the Security Instruments are valid and subsisting and secure each of the Borrowers’ obligations under the Loan Documents.

     Section 4.02 Guarantors Representations and Warranties. Each Guarantor represents and warrants that: (a) its representations and warranties contained in Article IV of the Credit Agreement and its representations and warranties contained in the Security Instruments, the Guaranties, and each of the other Loan Documents to which it is a party are true and correct in all material respects on and as of the Effective Date, as though made on and as of such date, except those representations and warranties that speak of a certain date, which representations and warranties remain true and correct as of such certain date; (b) no Default has occurred and is continuing; (c) the execution, delivery and performance of this Amendment are within the corporate power and authority of each of the Guarantors and have been duly authorized by appropriate corporate action and proceedings; (d) this Amendment constitutes the legal, valid, and binding obligation of each of the Guarantors enforceable in accordance with its terms, except as limited by applicable bankruptcy, insolvency, reorganization, moratorium, or similar laws affecting the rights of creditors generally and general principles of equity; (e) there are no governmental or other third party consents, licenses or approvals required in connection with the execution, delivery, performance, validity and enforceability of this Amendment; (f) it has no defenses to the enforcement of its Guaranty; and (g) the Liens under the Security Instruments are valid and subsisting and secure each Guarantor’s obligations under the Loan Documents.

ARTICLE V.
CONDITIONS

     This Amendment shall become effective and enforceable against the parties hereto, and the Credit Agreement shall be amended as provided herein, upon the occurrence of the following conditions precedent:

     Section 5.01 Documentation. The Administrative Agent shall have received multiple original counterparts, as requested by the Administrative Agent, of this Amendment, duly and validly executed and delivered by duly authorized officers of the Borrowers, the Guarantors, the Administrative Agent, the Issuing Lender and the Lenders.

     Section 5.02 Payment of Fees. The Borrowers shall have paid all costs and expenses that have been invoiced and are payable pursuant to Section 10.04 of the Credit Agreement.

     Section 5.03 No Default. No Default shall have occurred and be continuing.

     Section 5.04 Representations and Warranties. The representations and warranties contained in Article IV of the Credit Agreement and in each other Loan Document shall be true and correct in all material respects other than such representations and warranties that speak of a certain earlier date, which representations and warranties shall be true and correct as of such earlier date.

ARTICLE VI.
MISCELLANEOUS

     Section 6.01 Effect on Loan Documents; Acknowledgments.

          (a) Each of the Borrowers acknowledges that on the date hereof all Obligations are payable without defense, offset, counterclaim or recoupment.

          (b) The Administrative Agent, the Issuing Lender and the Lenders hereby expressly reserve all of their rights, remedies, and claims under the Loan Documents. Nothing in this Amendment shall constitute a waiver or relinquishment of (i) any Default or Event of Default under any of the Loan Documents, (ii) any of the agreements, terms or conditions contained in any of the Loan Documents other than as expressly set forth above, (iii) any rights or remedies of the Administrative Agent, the Issuing Lender or any Lender with respect to the Loan Documents, or (iv) the rights of the Administrative Agent, any Issuing Lender or any Lender to collect the full amounts owing to them under the Loan Documents.

          (c) Each of the Borrowers, the Guarantors, the Administrative Agent, the Issuing Lender and the Lenders does hereby adopt, ratify, and confirm the Credit Agreement, as amended hereby, and acknowledges and agrees that the Credit Agreement, as amended hereby, and all other Loan Documents are and remain in full force and effect, and each of the Borrowers and the Guarantors acknowledges and agrees that its liabilities under the Credit Agreement and the other Loan Documents are not impaired in any respect by this Amendment or the consents granted hereunder.

          (d) From and after the Effective Date, all references to the Credit Agreement and the Loan Documents shall mean such Credit Agreement and such Loan Documents as amended by this Amendment.

          (e) This Amendment is a Loan Document for the purposes of the provisions of the other Loan Documents. Without limiting the foregoing, any breach of representations, warranties, and covenants under this Amendment shall be a Default or Event of Default, as applicable, under the Credit Agreement.

     Section 6.02 Reaffirmation of the Guaranty. Each Guarantor hereby ratifies, confirms, acknowledges and agrees that its obligations under its Guaranty are in full force and effect and that such Guarantor continues to unconditionally and irrevocably guarantee the full and punctual payment, when due, whether at stated maturity or earlier by acceleration or otherwise, all of the Guaranteed Obligations (as defined in its Guaranty), as such Guaranteed Obligations may have been amended by this Amendment, and its execution and deliver of this

Amendment does not indicate or establish an approval or consent requirement by such Guarantor under its Guaranty in connection with the execution and delivery of amendments to the Credit Agreement, the Notes or any of the other Loan Documents.

     Section 6.03 Counterparts. This Amendment may be signed in any number of counterparts, each of which shall be an original and all of which, taken together, constitute a single instrument. This Amendment may be executed by facsimile signature and all such signatures shall be effective as originals.

     Section 6.04 Successors and Assigns. This Amendment shall be binding upon and inure to the benefit of the Lenders, the Borrowers and the Administrative Agent hereto and their respective successors and assigns permitted pursuant to the Credit Agreement.

     Section 6.05 Invalidity. In the event that any one or more of the provisions contained in this Amendment shall for any reason be held invalid, illegal or unenforceable in any respect, such invalidity, illegality or unenforceability shall not affect any other provision of this Amendment.

     Section 6.06 Governing Law. This Amendment shall be deemed to be a contract made under and shall be governed by and construed in accordance with the laws of the State of Texas.

     Section 6.07 Entire Agreement. THIS AMENDMENT, THE CREDIT AGREEMENT AS AMENDED BY THIS AMENDMENT, THE NOTES, AND THE OTHER LOAN DOCUMENTS CONSTITUTE THE ENTIRE UNDERSTANDING AMONG THE PARTIES HERETO WITH RESPECT TO THE SUBJECT MATTER HEREOF AND SUPERSEDE ANY PRIOR AGREEMENTS, WRITTEN OR ORAL, WITH RESPECT THERETO.

THERE ARE NO UNWRITTEN ORAL AGREEMENTS AMONG THE PARTIES.

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     EXECUTED effective as of the date first above written.

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(Mariner Energy, Inc. and Mariner Energy Resources, Inc.)

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(Mariner Energy, Inc. and Mariner Energy Resources, Inc.)

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(Mariner Energy, Inc. and Mariner Energy Resources, Inc.)

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(Mariner Energy, Inc. and Mariner Energy Resources, Inc.)