RATIFICATION OF AND AMENDMENT TO MORTGAGE, DEED OF TRUST, SECURITY AGREEMENT, FINANCING STATEMENT AND ASSIGNMENT OF PRODUCTION

Exhibit 10.23.9

RATIFICATION OF AND AMENDMENT TO

MORTGAGE, DEED OF TRUST, SECURITY AGREEMENT,

FINANCING STATEMENT AND ASSIGNMENT OF PRODUCTION

This instrument, dated effective the 24th day of February, 2010 (the “Effective Date”), is entered into by and between PRIMEENERGY CORPORATION (“Prime”), a Delaware corporation, and PRIMEENERGY MANAGEMENT CORPORATION (“PEMC”, and Prime and PEMC, collectively, the “Mortgagor”), a New York corporation, the address for each of which for purposes hereof being One Landmark Square, Suite 1100, Stamford, Connecticut ###-###-####, and COMPASS BANK, an Alabama banking association and successor in interest to Guaranty Bank, FSB, a federal savings bank, the address for which for purposes hereof being 24 Greenway Plaza, Suite 1400A, Houston, Texas 77046, in its capacity as administrative agent (in such capacity the “Mortgagee”) for the lenders party to that certain Amended and Restated Credit Agreement dated as of December 28, 2006 by and among Prime, PEMC, PRIME OPERATING COMPANY, a Texas corporation, EASTERN OIL WELL SERVICE COMPANY, a West Virginia corporation, SOUTHWEST OILFIELD CONSTRUCTION COMPANY, an Oklahoma corporation, EOWS MIDLAND COMPANY, a Texas corporation, and Guaranty Bank, FSB, a federal savings bank, individually as a lender and as administrative agent for the lenders signatory thereto from time to time (the “Lenders”) (as amended, supplemented, restated or otherwise modified from time to time, the “Credit Agreement”).

WITNESSETH:

WHEREAS, the Mortgagor has heretofore executed that certain security document more particularly described in Schedule 1 attached hereto and incorporated herein for all purposes by this reference (the “Security Document”);

WHEREAS, the benefits of the mortgagee and secured party under the Security Document are now owned and held by the Mortgagee; and

WHEREAS, the Mortgagor and the Mortgagee desire to ratify and amend the Security Document as described below;

NOW, THEREFORE, in consideration of the foregoing, the benefits to be derived by the Mortgagor under the Credit Agreement and other good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged by the Mortgagor, the parties hereto agree as follows:

1. INCLUSION OF ADDITIONAL MORTGAGED PROPERTY. The Security Document is hereby amended so as to subject to the liens and security interests thereof the oil, gas and mineral interests described in Exhibit A attached hereto and all elements of personalty associated therewith and as to which a security interest therein may be created pursuant to the Uniform Commercial Code, including, but not limited to, “as-extracted collateral”, as such term is defined in the Uniform Commercial Code, whether now owned and existing or hereafter acquired or arising and those enumerated in the Security Document (together with the interests presently subject to the Security Document, the “Mortgaged Property”). All references to the Mortgaged Property in the Security Document or herein shall be deemed to include, but not be limited to, the oil, gas and mineral interests described in Exhibit A hereto and personalty associated therewith.

2. SUBSTITUTION OF TRUSTEE. Effective as of the Effective Date, Richard G. Sylvan, the address for whom is 24 Greenway Plaza, Suite 1400A, Houston, Texas 77046, is substituted for John A. Clark as the Trustee under the Security Document and all references in the Security Document to the “Trustee” shall be references to Richard G. Sylvan.

3. WARRANTIES, REPRESENTATIONS AND COVENANTS. The warranties, representations and covenants of the Mortgagor contained in the Security Document are hereby remade by the Mortgagor to the Mortgagee, for the benefit of the Lenders, and are in full force and effect as of the date hereof. Such warranties, representations, and covenants shall apply with equal force and effect to the oil, gas and mineral interests described in Exhibit A hereto and personalty associated therewith.

4. REAFFIRMATION OF SECURITY DOCUMENT. To secure the Indebtedness (as such term is defined in the Security Document), the Mortgagor has granted, bargained, sold, mortgaged, assigned, transferred and conveyed, and by these presents does grant, bargain, sell, mortgage, assign, transfer and convey, unto Richard G. Sylvan, Trustee for the benefit of the Mortgagee, for the benefit of the Lenders, and grants to the Mortgagee, for the benefit of the Lenders, a security interest in, the Mortgaged Property (as such term is defined in the Security Document as amended hereby) not previously released from the lien and security interest of the Security Document, including, but not limited to, the oil, gas and mineral interests described in Exhibit A hereto and personalty associated therewith, in trust to secure the Indebtedness (as such term is defined in the Security Document).

TO HAVE AND TO HOLD the Mortgaged Property not previously released from the lien and security interest of the Security Document, together with the rights, privileges and appurtenances now or hereafter at any time before the release of the Security Document in anywise belonging or appertaining thereto, unto Richard G. Sylvan, Trustee for the benefit of the Mortgagee, for the benefit of the Lenders, to secure the payment of the Indebtedness (as such term is defined in the Security Document) and the agreements and covenants of the Mortgagor herein and in the Security Document.

5. MISCELLANEOUS. This instrument shall be considered as an amendment to and ratification of the Security Document, and the Security Document, as herein expressly amended, is hereby ratified, approved and confirmed in every respect. All liens created, extended or renewed by the Security Document are hereby extended, renewed and carried forward by this instrument and incorporated herein. All references to the Security Document in any documents heretofore or hereafter executed shall be deemed to refer to the Security Document as amended by this instrument.

(Signatures appear on following pages)

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IN WITNESS WHEREOF, the parties hereto have executed this instrument to be effective as of the Effective Date first hereinabove written.

(Signatures continue on following page)

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The foregoing instrument was acknowledged before me, the undersigned Notary Public, this 24th day of February, 2010, by Beverly A. Cummings, Executive Vice President, Treasurer, and Chief Financial Officer of each of PrimeEnergy Corporation, a Delaware corporation, and PrimeEnergy Management Corporation, a New York corporation, on behalf of each of such corporations.

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The foregoing instrument was acknowledged before me, the undersigned Notary Public, this 24th day of February, 2010, by Kathleen J. Bowen, a Senior Vice President of COMPASS BANK, an Alabama banking association, on behalf of such Alabama banking association, acting in the indicated capacity.

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SCHEDULE 1

Security Document

S1-i

EXHIBIT A

The designation “Working Interest” or “W.I.” when used in this Exhibit means an interest owned in an oil, gas, and mineral lease that determines the cost-bearing percentage of the owner of such interest. The designation “Net Revenue Interest” or “N.R.I.” means that portion of the production attributable to the owner of a working interest after deduction for all royalty burdens, overriding royalty burdens or other burdens on production, except severance, production, and other similar taxes. The designation “Overriding Royalty Interest” or “ORRI” means an interest in production which is free of any obligation for the expense of exploration, development, and production, bearing only its pro rata share of severance, production, and other similar taxes and, in instances where the document creating the overriding royalty interest so provides, costs associated with compression, dehydration, other treating or processing, or transportation of production of oil, gas, or other minerals relating to the marketing of such production. The designation “Royalty Interest” or “RI” means an interest in production which results from an ownership in the mineral fee estate or royalty estate in the relevant land and which is free of any obligation for the expense of exploration, development, and production, bearing only its pro rata share of severance, production, and other similar taxes and, in instances where the document creating the royalty interest so provides, costs associated with compression, dehydration, other treating or processing or transportation of production of oil, gas, or other minerals relating to the marketing of such production.

Any reference in this Exhibit to wells or units is for warranty of interest, administrative convenience, and identification and shall not limit or restrict the right, title, interest, or properties covered by this Deed of Trust. All right, title, and interest of Mortgagor in the properties described herein are and shall be subject to this Deed of Trust, regardless of the presence of any units or wells not described herein.

[Descriptions of the relevant Leases and

the relevant Land are found on the

following pages of this Exhibit]

A-i

Additional Mortgaged Property

Lease Recording

Lease Recording

Lease Recording

A-ii

Lease Recording

Lease Recording

A-iii

Lease Recording

Lease Recording

Lease Recording

A-iv

Lease Recording

Lease Recording

A-v

Lease Recording

Lease Recording

A-vi

Lease Recording

Lease Recording

A-vii

Lease Recording

A-viii

Property Description

Lease Recording

Lease Recording

Lease Recording

- 1 -

Lease Recording

Lease Recording

Lease Recording

- 2 -

Lease Recording

Lease Recording

- 3 -

Lease Recording

Lease Recording

Lease Recording

- 4 -

Lease Recording

Lease Recording

-5-

Lease Recording

-6-

Lease Recording

-7-