AMENDMENT NO. 1 TO STOCK PURCHASE AGREEMENT

Exhibit 2.2

Execution Copy

AMENDMENT NO. 1 TO STOCK PURCHASE AGREEMENT

This AMENDMENT NO. 1, dated as of December 12, 2011 (this “Amendment”), to the Stock Purchase Agreement, dated as of November 22, 2011 (the “Purchase Agreement”), is entered into by and among Samson Resources Corporation (formerly named Tulip Acquisition Corporation), a corporation existing under the laws of Delaware (“Purchaser”), Samson Investment Company, a Nevada corporation (the “Company”), and the stockholders of the Company listed on the signature pages hereof (collectively, the “Selling Stockholders”).

RECITALS

WHEREAS, the parties to the Purchase Agreement desire to amend and supplement certain terms of the Purchase Agreement as described herein; and

WHEREAS, all capitalized terms not defined herein shall have the meaning ascribed to such terms in the Purchase Agreement.

NOW, THEREFORE, in consideration of the premises and the mutual covenants and agreements hereinafter contained, the Parties hereby agree as follows:

ARTICLE I

AMENDMENTS

1.1 Definitions. The definition of “Adjustments to Purchase Price” set forth in Section 1.1 of the Purchase Agreement is hereby amended and restated in its entirety as follows:

“‘Adjustments to Purchase Price’ means an amount equal to the sum total of (a) the aggregate amount of the SAR Payments to be paid to the Company’s employees pursuant to Section 2.3, which the Company estimates to be $366,746,173, plus (b) the aggregate amount of Success/Retention Bonuses to be paid to the Company’s employees pursuant to Section 2.4, which the Company estimates to be $78,242,643, plus (c) the Jefferies Payments, plus (d) the aggregate gross amount of the 1.45% Medicaid tax payable by an employer with respect to the SAR Payments and the Success/Retention Bonuses, which the Company estimates to be $6,702,119, plus (e) the aggregate gross amount of tax imposed under Federal Insurance Contribution Act payable by an employer with respect to the SAR Payments and the Success/Retention Bonuses, which the Company estimates to be $983,434, plus (f) any prepayment fees, makewhole payments, premiums, penalties or expenses that are required to retire the Indebtedness of the Company at Closing pursuant to Section 2.2(c), plus (g) the Estimated Net Settlement Amount, plus (h) the principal and accrued and unpaid interest under any loans extended to a holder of SARs under the SAR Plan after June 30, 2011 that are outstanding at the Closing, less (i) the proceeds received by the Company or its Subsidiaries prior to Closing in respect of the repayment of principal and accrued and unpaid interest under any outstanding loans extended to a holder of SARs under the SAR Plan after June 30, 2011.”

1.2 Restricted Area.

(a) Section 8.1(ii) of the Purchase Agreement is hereby amended and restated in its entirety as follows:

“(ii) Conduct or participate in any Company Business within the Restricted Areas of Lone Star, Concorde and Offshore during the Twelve Month Restricted Period, except in respect of Properties acquired (x) pursuant to a merger or consolidation with another Person or (y) pursuant to the purchase of all or the majority of the assets or equity of another Person, and provided, in the case of clause (x) or (y), that less than ten percent (10%) of the acquired Properties lie within such Restricted Area; provided, however, that for purposes of this clause (ii) the Restricted Area of Lone Star, Concorde and Offshore shall not include that portion of the northwest corner of Montgomery County, Texas that is south of the Walker County line, east of the Grimes County line, west of Interstate Highway 45 and north of Texas State Highway 105, as further depicted in the plat set forth in Section 8.1 of the Disclosure Schedule; and”

(b) Section 8.2(ii) of the Purchase Agreement is hereby amended and restated in its entirety as follows:

“(ii) Conduct or participate in any Company Business within the Restricted Areas of the Company and its Subsidiaries during the Twelve Month Restricted Period, except in respect of Properties acquired (x) pursuant to a merger or consolidation with another Person or (y) pursuant to the purchase of all or the majority of the assets or equity of another Person, and provided, in the case of clause (x) or (y), that less than ten percent (10%) of the acquired Properties lie within such Restricted Area provided, however, that for purposes of this clause (ii) the Restricted Area of the Company and its Subsidiaries shall include that portion of the northwest corner of Montgomery County, Texas that is south of the Walker County line, east of the Grimes County line, west of Interstate Highway 45 and north of Texas State Highway 105, as further depicted in the plat set forth in Section 8.1 of the Disclosure Schedule; and”

1.3 Indebtedness. Section 10.14(b) of the Purchase Agreement is hereby amended and restated in its entirety as follows:

“(b) take all actions necessary to cause the Private Placement Notes to be redeemed and discharged at least two (2) Business Days prior to Closing, which actions shall include (i) timely issuing all necessary redemption and change of control notices to the holders of the Private Placement Notes pursuant to the terms of the instruments of Indebtedness governing the Private Placement Notes and (ii) borrowing under the Credit Facility all funds necessary to redeem in full the Private Placement Notes, including the payment of principal, accrued interest and any make-whole fees required thereunder; and”

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1.4 Annex B.

(a) The introductory paragraph in Section II.A.4 of Annex B to the Purchase Agreement is hereby amended and restated in its entirety as follows:

“4. Net Proceeds, Gains and Losses From Hedge Contracts. The amount of net realized and unrealized gains and losses for the Gulf Coast Division’s pro-rata share of (i) cash settlements of and (ii) the net change in the unrealized gain and losses attributable to each of the natural gas, crude oil and Houston Ship Channel basis (“HSC”) derivative hedge contracts which were either (x) owned by the Company as of June 30, 2011 or (y) established by the Company after June 30, 2011 and on or prior to November 10, 2011 shall be calculated and determined in the immediately following paragraphs (a) through (f). For the sake of clarity, no derivative hedge contracts established by the Company subsequent to November 10, 2011 will be considered to be partly owned by the Gulf Coast Division, and accordingly, no adjustments in respect of such contracts will be made hereunder.”

(b) Annex B to the Purchase Agreement is hereby amended and restated by insertion of a new Section II.D, which shall read in its entirely as follows:

“D. Adjustments to Purchase Price. The Post-Closing Statement shall include an adjustment for any aggregate difference in the sums determined in the final accounting for the items included in components (a), (b), (d) and (e) of the Adjustments to Purchase Price as compared to the sums stated in the definition of Adjustments to Purchase Price and used in determining the Net Share Consideration at Closing.”

1.5 Disclosure Schedule.

(a) Section 6.2 of the Disclosure Schedule is hereby amended and restated in its entirely as set forth on Annex A to this Amendment.

(b) Section 7.8(a)(iii) of the Disclosure Schedule is hereby amended and restated in its entirety as set forth on Annex B to this Amendment.

(c) Section 8.1 of the Disclosure Schedule is hereby added to the Disclosure Schedule in the form of Annex C to this Amendment.

ARTICLE II

MISCELLANEOUS

2.1 Governing Law. THIS AGREEMENT SHALL BE CONSTRUED, PERFORMED AND ENFORCED IN ACCORDANCE WITH THE LAWS OF THE STATE OF NEW YORK, WITHOUT GIVING EFFECT TO ITS PRINCIPLES OR RULES OF CONFLICT OF LAWS TO THE EXTENT SUCH PRINCIPLES OR RULES WOULD REQUIRE OR PERMIT THE APPLICATION OF THE LAWS OF ANOTHER JURISDICTION.

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2.2 Counterparts. This Agreement may be executed in any number of counterparts, all of which will be considered one and the same agreement and will become effective when counterparts have been signed by each of the Parties and delivered to the other Parties. It is not necessary that each Party execute the same counterpart so long as identical counterparts are executed by each such Party. This Agreement may be validly executed and delivered by facsimile or other electronic transmission.

2.3 Ratification. The Parties hereby ratify and approve the Purchase Agreement, as amended hereby, and the Parties acknowledge that all of the terms and provisions of the Purchase Agreement, as amended hereby, are and remain in full force and effect.

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IN WITNESS WHEREOF, the undersigned have caused this Amendment to be executed by their respective duly authorized officers as of the date first above set forth.

Amendment to Stock Purchase Agreement

Amendment to Stock Purchase Agreement

Annex A

DISCLOSURE SCHEDULE

TO

STOCK PURCHASE AGREEMENT

As part of its regular annual evaluation of the Company’s employee health and welfare plans, it is possible that changes will be made to the Company’s health and welfare plans (other than in respect to the qualification age for its Retiree Health Insurance Program) prior to December 31, 2011.

See Exhibits D-1 and D-2 to Disclosure Schedule attached hereto.

A-1

Annex B

DISCLOSURE SCHEDULE

TO

STOCK PURCHASE AGREEMENT

7.8(a)(iii) Tulsa, Oklahoma based Gulf Coast Division and Offshore employees.

B-1

B-2

Annex C

DISCLOSURE SCHEDULE

TO

STOCK PURCHASE AGREEMENT

C-1