Form 8-K

Unit Corporation

Date: May 11, 2011

/s/ Mark E. Schell

Mark E. Schell

Senior Vice President and General Counsel

Introductory. Unit Corporation, a Delaware corporation (the “Company”), proposes to issue and sell to the several underwriters named in Schedule A hereto (the “Underwriters”), for whom you (the “Representative”) are acting as representative, $250,000,000 principal amount of its 6⁵/8% Senior Subordinated Notes due 2021 (the “Notes”). The Notes will be guaranteed (collectively, the “Guarantees”) by each of the subsidiary guarantors named in Schedule B hereto (the “Guarantors”). The Notes and the Guarantees are collectively referred to herein as the “Securities.” The Securities will be issued pursuant to an indenture dated as of May 18, 2011 (the “Base Indenture”), among the Company, the Guarantors and Wilmington Trust FSB, as trustee (the “Trustee”). Certain terms of the Securities will be established pursuant to a supplemental indenture dated as of May 18, 2011 (the “Supplemental Indenture”) to the Base Indenture (together with the Base Indenture, the “Indenture”). To the extent there are no additional underwriters listed on Schedule A other than you, the term Representative as used herein shall mean you as the Underwriter. The use of the neuter in this Underwriting Agreement (the “Agreement”) shall include the feminine and masculine wherever appropriate.

The Company hereby confirms its engagement of BB&T Capital Markets, a division of Scott & Stringfellow, LLC (“BB&T”) as, and BB&T hereby confirms its agreement with the Company to render services as, the “qualified independent underwriter,” within the meaning of FINRA Rule 5121(f)(12) of the Financial Industry Regulatory Authority, Inc. (“FINRA”) with respect to the offering and sale of the Notes. BB&T, solely in its capacity as the qualified independent underwriter and not otherwise, is referred to herein as the “QIU.”

1. Representations and Warranties. The Company and each Guarantor, jointly and severally, represent and warrant to, and agree with, each of the Underwriters as of the date hereof that:

(a) The Company has prepared and filed with the Securities and Exchange Commission (the “Commission”) a registration statement on Form S-3 (File No. 333-173884), which contains a base prospectus (the “Base Prospectus”), to be used in connection with the public offering and sale of the Securities. Such registration statement, as amended, including the financial statements, exhibits and schedules thereto, at each time of effectiveness under the Securities Act of 1933, as amended, and the rules and regulations promulgated thereunder (collectively, the “Securities Act”), including any required information deemed to be a part thereof at the time of effectiveness pursuant to Rule

430B or 430C under the Securities Act or the Securities Exchange Act of 1934, as amended, and the rules and regulations promulgated thereunder (collectively, the “Exchange Act”), is called the “Registration Statement.” Any preliminary prospectus supplement relating to the Securities that is filed with the Commission pursuant to Rule 424(b), together with the Base Prospectus, is hereafter called a “Preliminary Prospectus.” The term “Prospectus” shall mean the final prospectus supplement relating to the Securities that is first filed pursuant to Rule 424(b) after the date and time that this Agreement is executed and delivered by the parties hereto, including the Base Prospectus. Any reference herein to the Registration Statement, any Preliminary Prospectus or the Prospectus shall be deemed to refer to and include the documents incorporated by reference therein pursuant to Item 12 of Form S-3 under the Securities Act; any reference to any amendment or supplement to any Preliminary Prospectus or the Prospectus shall be deemed to refer to and include any documents filed after the date of such Preliminary Prospectus or Prospectus, as the case may be, under the Exchange Act, and incorporated by reference in such Preliminary Prospectus or Prospectus, as the case may be; and any reference to any amendment to the Registration Statement shall be deemed to refer to and include any annual report of the Company filed pursuant to Section 13(a) or 15(d) of the Exchange Act after the effective date of the Registration Statement that is incorporated by reference in the Registration Statement.

(b) Compliance with Registration Requirements. The Company meets the requirements for use of Form S-3 under the Securities Act. The Registration Statement has become effective upon filing with the Commission under the Securities Act. No stop order suspending the effectiveness of the Registration Statement is in effect, the Commission has not issued any order or notice preventing or suspending the use of the Registration Statement, any Preliminary Prospectus or the Prospectus and no proceedings for such purpose or pursuant to Section 8A of the Securities Act have been instituted or are pending or, to the best knowledge of the Company and the Guarantors, are contemplated or threatened by the Commission.

Each of the Preliminary Prospectus and the Prospectus when filed complied in all material respects with the Securities Act. Each of the Registration Statement and any post-effective amendment thereto, at each time of effectiveness, at the date hereof and at the Closing Date, complied and will comply in all material respects with the Securities Act and did not and will not contain any untrue statement of a material fact or omit to state a material fact required to be stated therein or necessary in order to make the statements therein not misleading. The Prospectus, as amended or supplemented, as of its date, at the time of any filing pursuant to Rule 424(b) and, at the Closing Date, did not and will not contain any untrue statement of a material fact or omit to state a material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading. The representations and warranties set forth in the two immediately preceding sentences do not apply to statements in or omissions from the Registration Statement or any post-effective amendment thereto, or the Preliminary Prospectus or the Prospectus, or any amendments or supplements thereto, made in reliance upon and in conformity with information relating to any Underwriter furnished to the Company in writing by the Representative expressly for use therein, it being understood and agreed that the only such information furnished by the Representative consists of the information described as such in Section 8(b) hereof.

The documents incorporated by reference in the Registration Statement, the Disclosure Package (as defined herein) and the Prospectus, when they were filed with the Commission conformed in all material respects to the requirements of the Exchange Act. Any further documents so filed and incorporated by reference in the Registration Statement, the Disclosure Package and the Prospectus or any further amendment or supplement thereto, when such documents are filed with the Commission will conform in all material respects to the requirements of the Exchange Act. All documents incorporated or deemed to be incorporated by reference in the Registration Statement, the Disclosure Package and the Prospectus, as of their respective dates, when taken together with the other information in the Disclosure Package, at the Applicable Time and, when taken together with the other information in the Prospectus, at the Closing Date, did not or will not include an untrue statement of a material fact or omit to state a material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading.

(c) Well-Known Seasoned Issuer. (i) At the time of filing the Registration Statement, (ii) at the time of the most recent amendment thereto for the purposes of complying with Section 10(a)(3) of the Securities Act (whether such amendment was by post-effective amendment, incorporated report filed pursuant to Section 13 or 15(d) of the Exchange Act or form of prospectus), (iii) at the time the Company or any person acting on its behalf (within the meaning, for this clause only, of Rule 163(c) of the Securities Act) made any offer relating to the Securities in reliance on the exemption of Rule 163 of the Securities Act, and (iv) at the Applicable Time (with such date and time being used as the determination date for purposes of this clause (iv)), the Company was and is a “well-known seasoned issuer” as defined in Rule 405 of the Securities Act. The Registration Statement is an “automatic shelf registration statement,” as defined in Rule 405 of the Securities Act that has been filed with the Commission not earlier than three years prior to the Closing Date; the Company has not received from the Commission any notice pursuant to Rule 401(g)(2) of the Securities Act objecting to use of the automatic shelf registration statement form; and the Company has not otherwise ceased to be eligible to use the automatic shelf registration form.

(d) Disclosure Package. The term “Disclosure Package” shall mean (i) the Base Prospectus, including any Preliminary Prospectus as amended or supplemented (ii) the issuer free writing prospectuses as defined in Rule 433 of the Securities Act (each, an “Issuer Free Writing Prospectus”), if any, identified in Schedule C hereto, (iii) any other free writing prospectus that the parties hereto shall hereafter expressly agree in writing to treat as part of the Disclosure Package and (iv) the Final Term Sheet (as defined herein), which also shall be identified in Schedule C hereto. As of 12:00 pm (Eastern time) on the date of this Agreement (the “Applicable Time”), the Disclosure Package did not contain any untrue statement of a material fact or omit to state any material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading. The preceding sentence does not apply to statements in or omissions from the Disclosure Package based upon and in conformity with written information

furnished to the Company by any Underwriter through the Representative specifically for use therein, it being understood and agreed that the only such information furnished by or on behalf of any Underwriter consists of the information described as such in Section 8(b) hereof.

(e) Company Not Ineligible Issuer. (i) At the earliest time after the filing of the Registration Statement relating to the Securities that the Company or another offering participant made a bona fide offer (within the meaning of Rule 164(h)(2) of the Securities Act) and (ii) as of the Applicable Time (with such date being used as the determination date for purposes of this clause (ii)), the Company was not and is not an “ineligible issuer” (as defined in Rule 405 of the Securities Act), without taking account of any determination by the Commission pursuant to Rule 405 of the Securities Act that it is not necessary that the Company be considered an “ineligible issuer.”

(f) Issuer Free Writing Prospectuses. Each Issuer Free Writing Prospectus, as of its issue date and at all subsequent times through the completion of the offering of Securities under this Agreement or until any earlier date that the Company notified or notifies the Representative as described in the next sentence, did not, does not and will not include any information that conflicted, conflicts or will conflict with the information contained in the Registration Statement, the Disclosure Package or the Prospectus. If at any time following issuance of an Issuer Free Writing Prospectus there occurred or occurs an event or development as a result of which such Issuer Free Writing Prospectus conflicted or would conflict with the information contained in the Registration Statement, the Disclosure Package or the Prospectus, the Company has promptly notified or will promptly notify the Representative and has promptly amended or supplemented or will promptly amend or supplement, at its own expense, such Issuer Free Writing Prospectus to eliminate or correct such conflict. Any Issuer Free Writing Prospectus not identified on Schedule C, when taken together with the Disclosure Package, did not, and at the Closing Date will not, contain any untrue statement of a material fact or omit to state a material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading. The foregoing three sentences do not apply to statements in or omissions from any Issuer Free Writing Prospectus based upon and in conformity with written information furnished to the Company by any Underwriter through the Representative specifically for use therein, it being understood and agreed that the only such information furnished by any Underwriter consists of the information described as such in Section 8(b) hereof.

(g) Distribution of Offering Material by the Company and the Guarantors. Neither the Company nor any Guarantor has distributed or will distribute, prior to the later of the Closing Date and the completion of the Underwriters’ distribution of the Securities, any offering material in connection with the offering and sale of the Securities other than the Preliminary Prospectus, the Prospectus and any Issuer Free Writing Prospectus reviewed and consented to by the Representative.

(h) No Applicable Registration or Other Similar Rights. There are no persons with registration or other similar rights to have any equity or debt securities registered for sale under the Registration Statement or included in the offering contemplated by this Agreement, except for such rights as have been duly waived.

(i) No Material Adverse Change. Except as otherwise disclosed in the Disclosure Package and the Prospectus (exclusive of any amendment or supplement thereto), (i) there has been no material adverse change, or any development that could reasonably be expected to result in a material adverse change in the condition (financial or otherwise), earnings, business, properties, operations or prospects, whether or not arising from transactions in the ordinary course of business, of the Company and its subsidiaries, considered as one entity (any such change is called a “Material Adverse Change”); (ii) the Company and its subsidiaries, considered as one entity, have not incurred any liability or obligation, indirect, direct or contingent, nor entered into any material transaction or agreement, in each case, that is material to the Company and its subsidiaries taken as a whole; and (iii) there has been no dividend or distribution of any kind declared, paid or made by the Company or, except for dividends paid to the Company or other subsidiaries, any of its subsidiaries on any class of capital stock or repurchase or redemption by the Company or any of its subsidiaries of any class of capital stock.

(j) Incorporation and Good Standing of the Company and Its Subsidiaries. Each of the Company and its subsidiaries has been duly incorporated or formed and is validly existing and in good standing under the laws of the jurisdiction of its incorporation or organization and has the requisite power and authority, corporate or other, to own or lease, as the case may be, and operate its properties and to conduct its business as described in the Disclosure Package and the Prospectus and, in the case of the Company and the Guarantors, to enter into and perform its obligations under this Agreement. Each of the Company and each Guarantor is duly qualified as a foreign corporation or other entity to transact business and is in good standing in each jurisdiction in which such qualification is required, whether by reason of the ownership or leasing of property or the conduct of business, except for such jurisdictions where the failure to so qualify or to be in good standing would not, individually or in the aggregate, reasonably be expected to result in a Material Adverse Change. All of the issued and outstanding shares of capital stock or other ownership interests of each subsidiary have been duly authorized and validly issued, are fully paid and nonassessable and are owned by the Company, directly or through subsidiaries, free and clear of any security interest, mortgage, pledge, lien, encumbrance or claim. The Company does not own or control, directly or indirectly, any corporation, association or other entity other than the subsidiaries listed in Exhibit 21 to the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2010.

(k) Capitalization and Other Capital Stock Matters. The authorized, issued and outstanding capital stock of the Company is as set forth in the Disclosure Package and the Prospectus under the caption “Capitalization” (other than for subsequent issuances, if any, pursuant to employee benefit plans described in the Disclosure Package and the Prospectus or upon exercise of outstanding options or warrants described in the Disclosure Package and the Prospectus, as the case may be). The Common Stock conforms in all material respects to the description thereof contained in the Disclosure Package and the Prospectus. All of the issued and outstanding shares of Common Stock of the Company

have been duly authorized and validly issued, are fully paid and nonassessable and have been issued in compliance with federal and state securities laws. None of the outstanding shares of Common Stock were issued in violation of any preemptive rights, rights of first refusal or other similar rights to subscribe for or purchase securities of the Company. There are no authorized or outstanding options, warrants, preemptive rights, rights of first refusal or other rights to purchase, or equity or debt securities convertible into or exchangeable or exercisable for, any capital stock of the Company or any of its subsidiaries other than those accurately described in the Disclosure Package and the Prospectus. The description of the Company’s stock option, stock bonus and other stock plans or arrangements, and the options or other rights granted thereunder, set forth or incorporated by reference in each of the Disclosure Package and the Prospectus accurately and fairly presents the information required to be shown with respect to such plans, arrangements, options and rights.

(l) The Securities. The Notes to be purchased by the Underwriters from the Company are in the form contemplated by the Indenture, have been duly authorized by the Company for issuance and sale pursuant to this Agreement and the Indenture and, at the Closing Date, will have been duly executed by the Company and, when authenticated in the manner provided for in the Indenture and delivered against payment of the purchase price therefor, will constitute valid and binding obligations of the Company, enforceable in accordance with their terms, except as the enforcement thereof may be limited by bankruptcy, insolvency, fraudulent transfer, reorganization, moratorium or other similar laws relating to or affecting the rights and remedies of creditors or by general equitable principles and will be entitled to the benefits of the Indenture. The Guarantees of the Notes are in the respective forms contemplated by the Indenture, have been duly authorized by the Guarantors for issuance and sale pursuant to this Agreement and the Indenture and, at the Closing Date, will have been duly executed by each of the Guarantors and, when the Notes have been authenticated in the manner provided for in the Indenture and delivered against payment of the purchase price therefor, will constitute valid and binding obligations of the Guarantors, enforceable in accordance with their terms, except as the enforcement thereof may be limited by bankruptcy, insolvency, fraudulent transfer, reorganization, moratorium or other similar laws relating to or affecting the rights and remedies of creditors or by general equitable principles, and will be entitled to the benefits of the Indenture.

(m) The Indenture. The Indenture has been duly qualified under the Trust Indenture Act. The Indenture has been duly authorized by the Company and the Guarantors and, at the Closing Date, will have been duly executed and delivered by the Company and the Guarantors and will constitute a valid and binding agreement of the Company and the Guarantors, enforceable in accordance with its terms, except as the enforcement thereof may be limited by bankruptcy, insolvency, fraudulent transfer, reorganization, moratorium or other similar laws relating to or affecting the rights and remedies of creditors or by general equitable principles.

(n) Description of Documents. The Securities and the Indenture will conform in all material respects to the descriptions thereof in the Disclosure Package and the Prospectus under the captions “Description of the Notes” and “Description of the Debt Securities.”

(o) Regulations T, U and X. None of the transactions contemplated by this Agreement (including, without limitation, the use of the proceeds from the sale of the Securities) will violate or result in a violation of Section 7 of the Exchange Act, or any regulation promulgated thereunder, including, without limitation, Regulations T, U, and X of the Board of Governors of the Federal Reserve System.

(p) Non-Violation of Existing Instruments. Neither the Company nor any of its subsidiaries is (i) in violation or in default (or, with the giving of notice or lapse of time or both, would be in default) under (“Default”) its charter, by-laws or similar organizational documents, (ii) in Default under any indenture, mortgage, loan or credit agreement, deed of trust, note, contract, franchise, lease or other agreement or instrument to which the Company or such subsidiary is a party or by which it may be bound (including, without limitation, the First Amended and Restated Senior Credit Agreement, dated May 24, 2007, between the Company, including certain of its subsidiaries, and, among others, Bank of Oklahoma, N.A., as administrative agent and as co-arranger, Bank of America, N.A., as a co-arranger, BMO Capital Markets Financing, Inc, as syndication agent and Compass Bank, as document agent, and the Amendment to First Amended and Restated Senior Credit Agreement, dated December 23, 2008, between the Company, including certain of its subsidiaries, and, among others, Bank of Oklahoma, N.A., as administrative agent and as co-arranger, Bank of America, N.A., as a co-arranger, BMO Capital Markets Financing, Inc, as syndication agent and Compass Bank, as document agent), or to which any of the property or assets of the Company or any of its subsidiaries is subject (each, an “Existing Instrument”), or (iii) in violation of any statute, law, rule, regulation, judgment, order or decree of any court, regulatory body, administrative agency, governmental body, arbitrator or other authority having jurisdiction over the Company or such subsidiary or any of its properties, except, with respect to clause (ii) only, for such Defaults as would not, individually or in the aggregate, reasonably be expected to result in a Material Adverse Change. The Company’s and each Guarantor’s execution, delivery and performance of this Agreement and consummation of the transactions contemplated hereby (i) have been duly authorized by all necessary corporate (or similar) action and will not result in any Default under the charter or by-laws or similar organizational documents of the Company or any subsidiary, (ii) will not constitute a Default or a Debt Repayment Triggering Event (as defined below) under, or result in the creation or imposition of any lien, charge or encumbrance upon any property or assets of the Company or any of its subsidiaries pursuant to, or require the consent of any other party to, any Existing Instrument, and (iii) will not result in any violation of any statute, law, rule, regulation, judgment, order or decree applicable to the Company or any of its subsidiaries of any court, regulatory body, administrative agency, governmental body, arbitrator or other authority having jurisdiction over the Company or any of its subsidiaries or any of its or their properties. As used herein, a “Debt Repayment Triggering Event” means any event or condition which gives, or with the giving of notice or lapse of time would give, the holder of any note, debenture or other evidence of indebtedness (or any person acting on such holder’s behalf) the right to require the repurchase, redemption or repayment of all or a portion of such indebtedness by the Company or any of its subsidiaries.

(q) No Further Authorizations or Approvals Required. No consent, approval, authorization or other order of, or registration or filing with, any court or other governmental or regulatory authority or agency is required for the Company’s or any Guarantor’s execution, delivery and performance of this Agreement and consummation of the transactions contemplated hereby, except such as may be required under applicable state securities or blue sky laws.

(r) No Material Actions or Proceedings. There are no legal or governmental actions, suits or proceedings pending or, to the best of the Company’s and the Guarantors’ knowledge, threatened (i) against or affecting the Company or any of its subsidiaries, (ii) which have as the subject thereof any officer or director of, or property owned or leased by, the Company or any of its subsidiaries or (iii) relating to environmental or discrimination matters, where in any such case (A) there is a reasonable possibility that such action, suit or proceeding might be determined adversely to the Company or such subsidiary, or any officer or director of, or property owned or leased by the Company or any of its subsidiaries and (B) any such action, suit or proceeding, if so determined adversely, would reasonably be expected to result in a Material Adverse Change or adversely affect the consummation of the transactions contemplated by this Agreement.

(s) Exchange Act Compliance. The Company is subject to and in compliance in all material respects with the reporting requirements of Section 13 or 15(d) of the Exchange Act.

(t) Independent Accountants. PricewaterhouseCoopers LLP, who have expressed their opinion with respect to the financial statements (which term as used in this Agreement includes the related notes thereto) and supporting schedules, if any, included or incorporated by reference in the Registration Statement, the Disclosure Package and the Prospectus, are independent public accountants with respect to the Company as required by the Securities Act and the Exchange Act and the applicable published rules and regulations thereunder and the rules of the Public Company Accounting Oversight Board (United States).

(u) Preparation of Financial Statements. The financial statements filed with the Commission as a part of or incorporated by reference in the Registration Statement and included or incorporated by reference in the Disclosure Package and the Prospectus present fairly the consolidated financial position of the Company and its subsidiaries as of and at the dates indicated and the results of their operations and cash flows for the periods specified. The supporting schedules, if any, included or incorporated by reference in the Registration Statement present fairly the information required to be stated therein. Such financial statements and supporting schedules, if any, comply as to form with the applicable accounting requirements of Regulation S-X and have been prepared in conformity with U.S. generally accepted accounting principles applied on a consistent basis throughout the periods involved, except as may be expressly stated in the related notes thereto. No other financial statements or supporting schedules are required to be included

or incorporated by reference in the Registration Statement. The financial data set forth in the Preliminary Prospectus and the Prospectus under the captions “Prospectus Summary—Summary Historical Consolidated Financial Data,” “Selected Historical Consolidated Financial Data” and “Capitalization” fairly present the information set forth therein on a basis consistent with that of the audited financial statements contained in the Registration Statement. The Company’s ratios of earnings to fixed charges and pro forma ratios of earnings to fixed charges set forth in each of the Preliminary Prospectus and the Prospectus under the captions “Prospectus Summary—Summary Historical Consolidated Financial Data,” “Selected Historical Consolidated Financial Data” and in Exhibit 12 to the Registration Statement have been calculated in compliance in all material respects with the requirements of Item 503(d) of Regulation S-K under the Securities Act.

(v) This Agreement has been duly authorized, executed and delivered by the Company and each Guarantor.

(w) Intellectual Property Rights. The Company and its subsidiaries own, possess, license or have other rights to use, on reasonable terms, all patents, patent applications, trade and service marks, trade and service mark registrations, trade names, copyrights, licenses, inventions, trade secrets, technology, know-how and other intellectual property (collectively, the “Intellectual Property”) necessary for the conduct of the Company’s business as now conducted or as proposed in each of the Disclosure Package and the Prospectus to be conducted. Except as disclosed in the Disclosure Package and the Prospectus, (a) no party has been granted an exclusive license to use any portion of such Intellectual Property owned by the Company; (b) to the best of the knowledge of the Company and the Guarantors, there is no material infringement by third parties of any such Intellectual Property owned by or exclusively licensed to the Company and its subsidiaries; (c) there is no pending or, to the best of the knowledge of the Company and the Guarantors, threatened action, suit, proceeding or claim by others challenging the rights of the Company and its subsidiaries in or to any material Intellectual Property, and the Company and the Guarantors are unaware of any facts which would form a reasonable basis for any such claim; (d) there is no pending or, to the best of the knowledge of the Company and the Guarantors, threatened action, suit, proceeding or claim by others challenging the validity or scope of any such Intellectual Property, and the Company and the Guarantors are unaware of any facts which would form a reasonable basis for any such claim; and (e) there is no pending or, to the best of the knowledge of the Company and the Guarantors, threatened action, suit, proceeding or claim by others that the Company’s business as now conducted infringes or otherwise violates any patent, trademark, copyright, trade secret or other proprietary rights of others, and the Company and the Guarantors are unaware of any other fact which would form a reasonable basis for any such claim.

(x) All Necessary Permits, etc. The Company and each subsidiary possess such valid and current licenses, certificates, authorizations or permits issued by the appropriate state, federal or foreign regulatory agencies or bodies necessary to conduct their respective businesses, and neither the Company nor any subsidiary has received any notice of proceedings relating to the revocation or modification of, or non-compliance with, any such license, certificate, authorization or permit which, singly or in the aggregate, if the subject of an unfavorable decision, ruling or finding, would reasonably be expected to result in a Material Adverse Change.

(y) Title to Properties. The Company and each of its subsidiaries has (i) generally satisfactory title to all its interests in its oil and gas properties, title investigations having been carried out by the Company and each of its subsidiaries in accordance with the general practice in the oil and gas industry, and (ii) good and (in the case of real property only) marketable title to all the properties and assets reflected as owned in the financial statements referred to in Section 1(u) above (or elsewhere in the Disclosure Package and the Prospectus), in each case free and clear of any security interests, mortgages, liens, encumbrances, claims and other defects, except such as do not materially and adversely affect the value of such property and do not materially interfere with the use made or proposed to be made of such property by the Company or such subsidiary. The real property, improvements, equipment and personal property held under lease by the Company or any subsidiary are held under valid and enforceable leases, with such exceptions as do not materially interfere with the use made or proposed to be made of such real property, improvements, equipment or personal property by the Company or such subsidiary.

(z) Tax Law Compliance. The Company and its subsidiaries have filed all necessary federal, state, local and foreign income and franchise tax returns in a timely manner and have paid all taxes required to be paid by any of them and, if due and payable, any related or similar assessment, fine or penalty levied against any of them, except for any taxes, assessments, fines or penalties as may be being contested in good faith and by appropriate proceedings. The Company has made appropriate provisions in the applicable financial statements referred to in Section 1(u) above in respect of all federal, state, local and foreign income and franchise taxes for all current or prior periods as to which the tax liability of the Company or any of its subsidiaries has not been finally determined.

(aa) Company Not an “Investment Company.” Neither the Company nor any Guarantor is, or after receipt of payment for the Securities and the application of the proceeds thereof as contemplated under the caption “Use of Proceeds” in each of the Preliminary Prospectus and the Prospectus will be, an “investment company” within the meaning of the Investment Company Act and will conduct its business in a manner so that it will not become subject to the Investment Company Act of 1940, as amended (the “Investment Company Act”).

(bb) Insurance. Each of the Company and its subsidiaries are insured by recognized, financially sound and reputable institutions with policies in such amounts and with such deductibles and covering such risks as are generally deemed adequate and customary for their businesses including, but not limited to, policies covering real and personal property owned or leased by the Company and its subsidiaries against theft, damage, destruction, acts of vandalism and earthquakes. All policies of insurance insuring the Company or any of its subsidiaries or their respective businesses, assets, employees, officers and directors are in full force and effect; the Company and its subsidiaries are in compliance with the terms of such policies and instruments in all material respects; and there are no claims by the Company or any of its subsidiaries under any such policy or

instrument as to which any insurance company is denying liability or defending under a reservation of rights clause; and neither the Company nor any such subsidiary has been refused any insurance coverage sought or applied for. The Company has no reason to believe that it or any subsidiary will not be able (i) to renew its existing insurance coverage as and when such policies expire or (ii) to obtain comparable coverage from similar institutions as may be necessary or appropriate to conduct its business as now conducted and at a cost that would not result in a Material Adverse Change.

(cc) No Restrictions on Dividends. No subsidiary of the Company is currently prohibited, directly or indirectly, from paying any dividends to the Company, from making any other distribution on such subsidiary’s shares of capital stock or other ownership interests, from repaying to the Company any loans or advances to such subsidiary from the Company or from transferring any of such subsidiary’s property or assets to the Company or any other subsidiary of the Company, except as described in or contemplated by the Disclosure Package and the Prospectus.

(dd) Solvency. The Company and the Guarantors taken as a whole are, and immediately after the Closing Date will be, Solvent. As used herein, the term “Solvent” means, with respect to any person on a particular date, that on such date (i) the fair market value of the assets of such person is greater than the total amount of liabilities (including contingent liabilities) of such person, (ii) the present fair salable value of the assets of such person is greater than the amount that will be required to pay the probable liabilities of such person on its debts as they become absolute and matured, (iii) such person is able to realize upon its assets and pay its debts and other liabilities, including contingent obligations, as they mature and (iv) such person does not have unreasonably small capital.

(ee) No Price Stabilization or Manipulation. The Company has not taken and will not take, directly or indirectly, any action designed to or that might be reasonably expected to cause or result in stabilization or manipulation of the price of any security of the Company to facilitate the sale or resale of the Securities.

(ff) Related Party Transactions. There are no business relationships or related-party transactions involving the Company or any subsidiary required to be described in the Preliminary Prospectus or the Prospectus that have not been described as required.

(gg) Disclosure Controls. The Company and its subsidiaries maintain an effective system of “disclosure controls and procedures” (as defined in Rule 13a-15(e) under the Exchange Act). The Company and its subsidiaries have carried out evaluations of the effectiveness of their disclosure controls and procedures as required by Rule 13a-15 of the Exchange Act.

(hh) Internal Controls and Procedures. The Company maintains (i) effective internal control over financial reporting as defined in Rule 13a-15 and Rule 15d-15 under the Exchange Act, and (ii) a system of internal accounting controls sufficient to provide reasonable assurance that (A) transactions are executed in accordance with management’s general or specific authorizations; (B) transactions are recorded as necessary to permit preparation of financial statements in conformity with generally accepted accounting

principles and to maintain asset accountability; (C) access to assets is permitted only in accordance with management’s general or specific authorization; and (D) the recorded accountability for assets is compared with the existing assets at reasonable intervals and appropriate action is taken with respect to any differences.

(ii) No Material Weakness in Internal Controls. Except as disclosed in the Disclosure Package and the Prospectus, or in any document incorporated by reference therein, since the end of the Company’s most recent fiscal year, there has been (i) no material weakness in the Company’s internal control over financial reporting (whether or not remediated) and (ii) no change in the Company’s internal control over financial reporting that has materially affected, or is reasonably likely to materially affect, the Company’s internal control over financial reporting.

(jj) No Unlawful Contributions or Other Payments. Neither the Company nor any of its subsidiaries nor, to the knowledge of the Company and the Guarantors, any director, officer, agent, employee or affiliate of the Company or any of its subsidiaries is aware of or has taken any action, directly or indirectly, that would result in a violation by such persons of the FCPA, including, without limitation, making use of the mails or any means or instrumentality of interstate commerce corruptly in furtherance of an offer, payment, promise to pay or authorization of the payment of any money, or other property, gift, promise to give, or authorization of the giving of anything of value to any “foreign official” (as such term is defined in the FCPA) or any foreign political party or official thereof or any candidate for foreign political office, in contravention of the FCPA, and the Company, its subsidiaries and, to the knowledge of the Company and the Guarantors, its affiliates have conducted their businesses in compliance with the FCPA and have instituted and maintain policies and procedures designed to ensure, and which are reasonably expected to continue to ensure, continued compliance therewith. “FCPA” means the Foreign Corrupt Practices Act of 1977, as amended, and the rules and regulations thereunder.

(kk) No Conflict with Money Laundering Laws. The operations of the Company and its subsidiaries are and have been conducted at all times in compliance with applicable financial recordkeeping and reporting requirements of the Currency and Foreign Transactions Reporting Act of 1970, as amended, the money laundering statutes of all applicable jurisdictions, the rules and regulations thereunder and any related or similar rules, regulations or guidelines issued, administered or enforced by any governmental agency (collectively, the “Money Laundering Laws”) and no action, suit or proceeding by or before any court or governmental agency, authority or body or any arbitrator involving the Company or any of its subsidiaries with respect to the Money Laundering Laws is pending or, to the best knowledge of the Company and the Guarantors, threatened.

(ll) No Conflict with OFAC Laws. Neither the Company nor any of its subsidiaries nor, to the knowledge of the Company and the Guarantors, any director, officer, agent, employee or affiliate of the Company or any of its subsidiaries is currently subject to any U.S. sanctions administered by the Office of Foreign Assets Control of the U.S. Treasury Department (“OFAC”); and the Company will not directly or indirectly use the

proceeds of the offering, or lend, contribute or otherwise make available such proceeds, to any subsidiary, joint venture partner or other person or entity, for the purpose of financing the activities of any person currently subject to any U.S. sanctions administered by OFAC.

(mm) Compliance with and Liability Under Environmental Laws. Except as otherwise disclosed in the Disclosure Package and the Prospectus, (i) neither the Company nor any of its subsidiaries is in violation of any federal, state, local or foreign law, regulation, order, permit or other requirement relating to pollution or protection of human health or the environment (including, without limitation, ambient air, surface water, groundwater, land surface or subsurface strata and natural resources such as wetlands, flora and fauna), including without limitation, laws and regulations relating to emissions, discharges, releases or threatened releases of chemicals, pollutants, contaminants, pesticides, wastes, toxic substances, hazardous substances, petroleum and petroleum products (collectively, “Materials of Environmental Concern”), or otherwise relating to the manufacture, processing, distribution, use, treatment, storage, disposal, transport or handling of Materials of Environment Concern (collectively, “Environmental Laws”), which violation includes, but is not limited to, noncompliance with any permits or other governmental authorizations required for the operation of the business of the Company or its subsidiaries under applicable Environmental Laws, or noncompliance with the terms and conditions thereof, nor has the Company or any of its subsidiaries received any written communication, whether from a governmental authority, citizens group, employee or otherwise, that alleges that the Company or any of its subsidiaries is in violation of any Environmental Law, except as would not reasonably be expected to, individually or in the aggregate, result in a Material Adverse Change; (ii) there is no claim, action or cause of action filed with a court or governmental authority, no investigation with respect to which the Company has received written notice, and no written notice by any person or entity alleging actual or potential liability under any Environmental Law, including, without limitation, liability for investigatory costs, cleanup costs, governmental response costs, natural resource damages, property damages, personal injuries, attorneys’ fees or penalties arising out of, based on or resulting from the presence, or release into the environment, of any Material of Environmental Concern at any location (collectively, “Environmental Claims”), pending or, to the best of the Company’s and the Guarantors’ knowledge, threatened against the Company or any of its subsidiaries or any person or entity whose liability for any Environmental Claim the Company or any of its subsidiaries has retained or assumed either contractually or by operation of law, except as would not, individually or in the aggregate, reasonably be expected to result in a Material Adverse Change; (iii) to the best of the Company’s and the Guarantors’ knowledge, there are no past, present or anticipated future actions, activities, circumstances, conditions, events or incidents, including, without limitation, the release, emission, discharge, presence or disposal of any Material of Environmental Concern, that could reasonably be expected to result in a violation of any Environmental Law, require expenditures to be incurred pursuant to Environmental Law, or form the basis of a potential Environmental Claim against the Company or any of its subsidiaries or against any person or entity whose liability for any Environmental Claim the Company or any of its subsidiaries has retained or assumed either contractually or by operation of law, except as would not, individually

or in the aggregate, reasonably be expected to result in a Material Adverse Change; and (iv) neither the Company nor any of its subsidiaries is subject to any pending or, to the best of the knowledge of the Company and the Guarantors, threatened proceeding under Environmental Law to which a governmental authority is a party and which is reasonably likely to result in monetary sanctions of $100,000 or more.

(nn) Periodic Review of Costs of Environmental Compliance. In the ordinary course of its business, the Company conducts a periodic review of the effect of Environmental Laws on the business, operations and properties of the Company and its subsidiaries, in the course of which it identifies and evaluates associated costs and liabilities (including, without limitation, any capital or operating expenditures required for clean-up, closure of properties or compliance with Environmental Laws or any permit, license or approval, any related constraints on operating activities and any potential liabilities to third parties). On the basis of such review and the amount of its established reserves, the Company has reasonably concluded that such associated costs and liabilities would not, individually or in the aggregate, result in a Material Adverse Change.

(oo) ERISA Compliance. None of the following events has occurred or exists: (i) a failure to fulfill the obligations, if any, under the minimum funding standards of Section 302 of the United States Employee Retirement Income Security Act of 1974, as amended (“ERISA”), and the regulations and published interpretations thereunder with respect to a Plan, determined without regard to any waiver of such obligations or extension of any amortization period; (ii) an audit or investigation by the Internal Revenue Service, the U.S. Department of Labor, the Pension Benefit Guaranty Corporation or any other federal or state governmental agency or any foreign regulatory agency with respect to the employment or compensation of employees by any member of the Company that would reasonably be expected to result in a Material Adverse Change; or (iii) any breach of any contractual obligation, or any violation of law or applicable qualification standards, with respect to the employment or compensation of employees by any member of the Company that would reasonably be expected to result in a Material Adverse Change. None of the following events has occurred or is reasonably likely to occur: (i) a material increase in the aggregate amount of contributions required to be made to all Plans in the current fiscal year of the Company compared to the amount of such contributions made in the Company’s most recently completed fiscal year; (ii) a material increase in the Company’s “accumulated post-retirement benefit obligations” (within the meaning of Statement of Financial Accounting Standards 106) compared to the amount of such obligations in the Company’s most recently completed fiscal year; (iii) any event or condition giving rise to a liability under Title IV of ERISA that would reasonably be expected to result in a Material Adverse Change; (iv) any prohibited transaction, within the meaning of Section 406 of ERISA or Section 4975 of the Code, with respect to any pension plan or welfare plan (excluding transactions effected pursuant to a statutory or administrative exemption) that would reasonably be expected to result in a Material Adverse Change; or (v) the filing of a claim by one or more employees or former employees of the Company related to their employment that would reasonably be expected to result in a Material Adverse Change. For purposes of this paragraph, the term “Plan” means a plan (within the meaning of Section 3(3) of ERISA) subject to Title IV of ERISA with respect to which any member of the Company may have any liability.

(pp) Labor Matters. No labor disturbances by the employees of the Company or any of its subsidiaries has occurred that would, individually or in the aggregate, reasonably be expected to result in a Material Adverse Change.

(qq) Brokers. Other than the underwriting discount pursuant to Section 2 of this Agreement and the compensation to be paid to the QIU pursuant to this Agreement, there is no broker, finder or other party that is entitled to receive from the Company any brokerage or finder’s fee or other fee or commission as a result of any transactions contemplated by this Agreement.

(rr) No Outstanding Loans or Other Indebtedness. There are no outstanding loans, advances (except normal advances for business expenses in the ordinary course of business) or guarantees or indebtedness by the Company to or for the benefit of any of the officers or directors of the Company or any of the members of any of them, except as disclosed in the Disclosure Package and the Prospectus.

(ss) Sarbanes-Oxley Compliance. The Company and its directors and officers, in their capacities as such, are in compliance in all material respects with the applicable provisions of the Sarbanes-Oxley Act of 2002 and the rules and regulations promulgated in connection therewith (the “Sarbanes-Oxley Act”), including Section 402 related to loans and Sections 302 and 906 related to certifications.

(tt) Ratings. Except as otherwise disclosed in the Disclosure Package, no “nationally recognized statistical rating organization” as such term is defined for purposes of Rule 436(g)(2) under the Securities Act (i) has imposed (or has informed the Company that it is considering imposing) any condition (financial or otherwise) on the Company’s retaining any rating assigned to the Company, any securities of the Company or (ii) has indicated to the Company that it is considering (a) the downgrading, suspension, or withdrawal of, or any review for a possible change that does not indicate the direction of the possible change in, any rating so assigned or (b) any change in the outlook for any rating of the Company or any securities of the Company.

(uu) Subsidiaries. The subsidiaries listed on Annex A attached hereto are the only significant subsidiaries of the Company as defined by Rule 1-02 of Regulation S-X (the “Subsidiaries”).

(vv) Lending Relationship. Except as disclosed in the Disclosure Package and the Prospectus, the Company (i) does not have any material lending or other relationship with any bank or lending affiliate of any Underwriter and (ii) does not intend to use any of the proceeds from the sale of the Securities hereunder to repay any outstanding debt owed to any affiliate of any Underwriter.

(ww) Statistical and Market Related Data. Nothing has come to the attention of the Company that has caused the Company to believe that the statistical and market-related data included in each of the Disclosure Package and the Prospectus are not based on or derived from sources that are reliable and accurate in all material respects.

(xx) Reserves Information. Ryder Scott Company L.P. (“Ryder Scott”), a petroleum engineering firm from whose reserve reports information (the “Reserve Information”) is included or incorporated by reference in the Disclosure Package and the Prospectus, are independent petroleum engineers with respect to the Company and its subsidiaries. Other than (i) the production of reserves in the ordinary course of business, (ii) intervening price fluctuations or (iii) as described in the Disclosure Package and the Prospectus, the Company is not aware of any facts or circumstances that would result in a Material Adverse Change in its proved reserves in the aggregate, or the aggregate present value of estimated future net revenues of the Company or the standardized measure of discounted future net cash flows therefrom, as described in the Disclosure Package and the Prospectus and reflected in the Reserve Information as of the respective dates such information is given. Estimates of the proved reserves and the present value of the estimated future net revenues and the discounted future net cash flows derived therefrom as described in the Disclosure Package and the Prospectus and reflected in the Reserve Information comply in all material respects to the applicable requirements of Regulation S-X of the Securities Act Regulations and Industry Guide 2 under the Securities Act.

Any certificate signed by an officer of the Company and delivered to the Representative or to counsel for the Underwriters shall be deemed to be a representation and warranty by the Company to each Underwriter as to the matters set forth therein.

2. Purchase and Sale. The Company agrees to issue and sell to the several Underwriters the Notes upon the terms herein set forth and, on the basis of the representations, warranties and agreements and upon the terms but subject to the conditions herein set forth, the Underwriters agree, severally and not jointly, to purchase from the Company the respective aggregate principal amount of Notes set forth opposite their names on Schedule A. The purchase price per Note to be paid by the several Underwriters to the Company shall be equal to 98% of the principal amount thereof.

3. Delivery and Payment; Representations and Warranties and Covenants of the Underwriters.

(a) Delivery of certificates for the Securities to be purchased by the Underwriters and payment therefor shall be made at the offices of Davis Polk & Wardwell LLP (or such other place as may be agreed to by the Company and the Representative) at 9:00 a.m. New York time, on May 18, 2011, or such other time and date not later than 1:30 p.m. New York time, on June 1, 2011, as the Representative shall designate by notice to the Company (the time and date of such closing are called the “Closing Date”). Delivery of the Securities shall be made through the facilities of The Depository Trust Company (“DTC”) unless the Representative shall otherwise instruct.

(b) Public Offering of the Notes. The Representative hereby advises the Company that the Underwriters intend to offer for sale to the public, as described in the Disclosure Package and the Prospectus, their respective portions of the Notes as soon after this Agreement has been executed the Representative, in its sole judgment, has determined is advisable and practicable.

(c) Payment for the Notes. Payment for the Notes shall be made on the Closing Date by wire transfer of immediately available funds to the order of the Company.

It is understood that the Representative has been authorized, for its own account and the accounts of the several Underwriters, to accept delivery of and receipt for, and make payment of the purchase price for, the Notes. Merrill Lynch, Pierce, Fenner & Smith Incorporated (“Merrill Lynch”), individually and not as the Representative of the Underwriters, may (but shall not be obligated to) make payment for any Notes to be purchased by any Underwriter whose funds shall not have been received by the Representative by the Closing Date for the account of such Underwriter, but any such payment shall not relieve such Underwriter from any of its obligations under this Agreement.

(d) Delivery of the Notes. Delivery of the Notes shall be made through the facilities of DTC unless the Representative shall otherwise instruct. Time shall be of the essence, and delivery at the time and place specified in this Agreement is a further condition to the obligations of the Underwriters.

(e) Delivery of Prospectus to the Underwriters. Not later than 10:00 a.m. on the second business day following the date the Notes are first released by the Underwriters for sale to the public, the Company shall deliver or cause to be delivered, copies of the Prospectus in such quantities and at such places as the Representative shall reasonably request.

4. Covenants. The Company and the Guarantors, jointly and severally, covenant and agree with each of the Underwriters as follows:

(a) Representative Review of Proposed Amendments and Supplements. During the period beginning at the Applicable Time and ending on the later of the Closing Date or such date, as in the opinion of counsel for the Underwriters, the Prospectus is no longer required by law to be delivered in connection with sales by an Underwriter or dealer, including in circumstances where such requirement may be satisfied pursuant to Rule 172 (the “Prospectus Delivery Period”), prior to amending or supplementing the Registration Statement, the Disclosure Package or the Prospectus, the Company shall furnish to the Representative for review a copy of each such proposed amendment or supplement, and the Company shall not file or use any such proposed amendment or supplement to which the Representative reasonably objects.

(b) Securities Act Compliance. After the date of this Agreement and during the Prospectus Delivery Period, the Company shall promptly advise the Representative in writing (i) when the Registration Statement, if not effective at the Applicable Time, shall have become effective, (ii) of the receipt of any comments of, or requests for additional or supplemental information from, the Commission, (iii) of the time and date of any filing of any post-effective amendment to the Registration Statement or any amendment or supplement to any Preliminary Prospectus or the Prospectus, (iv) of the time and date that any post-effective amendment to the Registration Statement becomes effective, and (v) of

the issuance by the Commission of any stop order suspending the effectiveness of the Registration Statement or of any order or notice preventing or suspending the use of the Registration Statement, any Preliminary Prospectus or the Prospectus, or of any receipt by the Company of any notification with respect to the suspension of the qualification of the Notes for sale in any jurisdiction or of the threatening or initiation of any proceedings for any of such purposes (including any notice or order pursuant to Section 8A or Rule 401(g)(2) of the Securities Act). The Company shall use commercially reasonable efforts to prevent the issuance of any such stop order or notice of prevention or suspension of such use. If the Commission shall enter any such stop order or issue any such notice at any time, the Company will use commercially reasonable efforts to obtain the lifting or reversal of such order or notice at the earliest possible moment, or, subject to Section 4(a), will file an amendment to the Registration Statement or will file a new registration statement and use its best efforts to have such amendment or new registration statement declared effective as soon as practicable. Additionally, the Company agrees that it shall comply with the provisions of Rules 424(b) and 430B, as applicable, under the Securities Act, including with respect to the timely filing of documents thereunder, and will use commercially reasonable efforts to confirm that any filings made by the Company under such Rule 424(b) were received in a timely manner by the Commission.

(c) Exchange Act Compliance. During the Prospectus Delivery Period, the Company will file all documents required to be filed with the Commission and the New York Stock Exchange pursuant to Section 13, 14 or 15 of the Exchange Act in the manner and within the time periods required by the Exchange Act.

(d) Final Term Sheet. The Company will prepare a final term sheet in a form approved by the Representative, and will file such term sheet pursuant to Rule 433(d) under the Securities Act within the time required by such rule (such term sheet, the “Final Term Sheet”).

(e) Permitted Free Writing Prospectuses. The Company represents that it has not made, and agrees that, unless it obtains the prior written consent of the Representative, it will not make, any offer relating to the Notes that constitutes or would constitute an Issuer Free Writing Prospectus or that otherwise constitutes or would constitute a “free writing prospectus” (as defined in Rule 405 of the Securities Act) or a portion thereof required to be filed by the Company with the Commission or retained by the Company under Rule 433 of the Securities Act; provided that the prior written consent of the Representative hereto shall be deemed to have been given in respect of the Free Writing Prospectuses included in Schedule C hereto and any electronic road show. Any such free writing prospectus consented to by the Representative is hereinafter referred to as a “Permitted Free Writing Prospectus.” The Company agrees that (i) it has treated and will treat, as the case may be, each Permitted Free Writing Prospectus as an Issuer Free Writing Prospectus, and (ii) has complied and will comply, as the case may be, with the requirements of Rules 164 and 433 of the Securities Act applicable to any Permitted Free Writing Prospectus, including in respect of timely filing with the Commission, legending and record keeping. The Company consents to the use by any Underwriter of a free writing prospectus that (a) is not an “issuer free writing prospectus” as defined in Rule 433, or (b) contains only (1) information describing the preliminary terms of the Securities or

their offering, (2) information that describes the final terms of the Securities or their offering and that is included in the Final Term Sheet of the Company contemplated in Section 1(d) or (3) information permitted under Rule 134 under the Securities Act; provided that each Underwriter severally covenants with the Company not to take any action without the Company’s consent which consent shall be confirmed in writing that would result in the Company being required to file with the Commission under Rule 433(d) under the Securities Act a free writing prospectus prepared by or on behalf of such Underwriter that otherwise would not be required to be filed by the Company thereunder, but for the action of the Underwriter.

(f) Amendments and Supplements to the Registration Statement, Disclosure Package and Prospectus and Other Securities Act Matters. If, during the Prospectus Delivery Period, any event or development shall occur or condition exist as a result of which the Disclosure Package or the Prospectus as then amended or supplemented would include any untrue statement of a material fact or omit to state any material fact necessary in order to make the statements therein in the light of the circumstances under which they were made or then prevailing, as the case may be, not misleading, or if it shall be necessary to amend or supplement the Disclosure Package or the Prospectus, or to file under the Exchange Act any document incorporated by reference in the Disclosure Package or the Prospectus, in order to make the statements therein, in the light of the circumstances under which they were made or then prevailing, as the case may be, not misleading, or if in the opinion of the Representative it is otherwise necessary to amend or supplement the Registration Statement, the Disclosure Package or the Prospectus, or to file under the Exchange Act any document incorporated by reference in the Disclosure Package or the Prospectus, or to file a new registration statement containing the Prospectus, in order to comply with law, including in connection with the delivery of the Prospectus, the Company agrees to (i) notify the Representative of any such event or condition and (ii) promptly prepare (subject to Section 4(a) and 4(e) hereof), file with the Commission (and use its best efforts to have any amendment to the Registration Statement or any new registration statement to be declared effective) and furnish at its own expense to the Underwriters and to dealers, amendments or supplements to the Registration Statement, the Disclosure Package or the Prospectus, or any new registration statement, necessary in order to make the statements in the Disclosure Package or the Prospectus as so amended or supplemented, in the light of the circumstances under which they were made or then prevailing, as the case may be, not misleading or so that the Registration Statement, the Disclosure Package or the Prospectus, as amended or supplemented, will comply with law.

(g) Copies of Any Amendments and Supplements to the Prospectus. The Company agrees to furnish to the Representative, without charge, during the Prospectus Delivery Period, as many copies of the Prospectus and any amendments and supplements thereto (including any documents incorporated or deemed incorporated by reference therein) and the Disclosure Package as the Representative may request.

(h) Copies of the Registration Statements and the Prospectus. The Company will furnish to the Representative and counsel for the Underwriters signed copies of the Registration Statement and of each amendment thereto (including exhibits filed therewith or incorporated by reference therein and documents incorporated or deemed to be incorporated

by reference therein) and, during the Prospectus Delivery Period, as many copies of each Preliminary Prospectus, the Prospectus and any supplement thereto and the Disclosure Package as the Representative may reasonably request.

(i) Blue Sky Compliance. The Company and the Guarantors shall cooperate with the Representative and counsel for the Underwriters to qualify or register the Securities for sale under (or obtain exemptions from the application of) the state securities or blue sky laws or Canadian provincial securities laws or other foreign laws of those jurisdictions designated by the Representative and consented to by the Company, and the Company and the Guarantors shall comply in all material respects with such laws and shall continue such qualifications, registrations and exemptions in effect so long as required for the distribution of the Securities. Neither the Company nor any Guarantor shall be required to (i) qualify as a foreign corporation or other entity or as a dealer in securities in any such jurisdiction where it would not otherwise be required to so qualify, (ii) file any general consent to service of process in any such jurisdiction or (iii) subject itself to taxation in any such jurisdiction if it is not otherwise so subject. The Company and the Guarantors will advise the Representative promptly of the suspension of the qualification or registration of (or any such exemption relating to) the Securities for offering, sale or trading in any jurisdiction or any initiation or threat of any proceeding for any such purpose, and in the event of the issuance of any order suspending such qualification, registration or exemption, the Company and the Guarantors shall use their best efforts to obtain the withdrawal thereof at the earliest possible moment.

(j) Use of Proceeds. The Company shall apply the net proceeds from the sale of the Securities sold by it in the manner described under the caption “Use of Proceeds” in each of the Disclosure Package and the Prospectus.

(k) Agreement Not to Offer to Sell Additional Securities. During the period of 180 days following the date of this Agreement, the Company will not, without the prior written consent of Merrill Lynch (which consent may be withheld at the sole discretion of Merrill Lynch), directly or indirectly, sell, offer, contract or grant any option to sell, pledge, transfer or establish an open “put equivalent position” within the meaning of Rule 16a-1 under the Exchange Act, or otherwise dispose of or transfer, or announce the offering of, or file any registration statement under the Securities Act in respect of, any debt securities of the Company or securities exchangeable for or convertible into debt securities of the Company (other than as contemplated by this Agreement).

(l) DTC. The Company shall use commercially reasonable efforts to obtain the approval of DTC to permit the Notes to be eligible for “book-entry” transfer and settlement through the facilities of DTC, and agrees to comply with all of its agreements set forth in the representation letters of the Company to DTC relating to the approval of the Notes by DTC for “book-entry” transfer.

(m) Earnings Statement. As soon as practicable, the Company will make generally available to its security holders and to the Representative an earnings statement (which need not be audited) covering a period of at least twelve months beginning with the first fiscal quarter of the Company occurring after the “effective date” (as defined in Rule 158 under the Securities Act) of the Registration Statement.

(n) Periodic Reporting Obligations. During the Prospectus Delivery Period the Company shall file, on a timely basis, with the Commission and the New York Stock Exchange all reports and documents required to be filed under the Exchange Act.

(o) Filing Fees. The Company agrees to pay the required Commission filing fees relating to the Securities within the time required by Rule 456(b)(1) of the Securities Act without regard to the proviso therein and otherwise in accordance with Rules 456(b) and 457(r) of the Securities Act.

(p) Compliance with Sarbanes-Oxley Act. During the Prospectus Delivery Period, the Company will comply with all applicable securities and other laws, rules and regulations, including, without limitation, the Sarbanes-Oxley Act, and use its best efforts to cause the Company’s directors and officers, in their capacities as such, to comply with such laws, rules and regulations, including, without limitation, the provisions of the Sarbanes-Oxley Act.

(q) Future Reports to the Representative. During the period of two years hereafter the Company will furnish to the Representative (i) to the extent not available on the Commission’s Next-Generation EDGAR filing system, as soon as practicable after the end of each fiscal year, copies of the Annual Report of the Company containing the balance sheet of the Company as of the close of such fiscal year and statements of income, stockholders’ equity and cash flows for the year then ended and the opinion thereon of the Company’s independent public or certified public accountants; and (ii) to the extent not available on the Commission’s Next-Generation EDGAR filing system, as soon as practicable after the filing thereof, copies of each proxy statement, Annual Report on Form 10-K, Quarterly Report on Form 10-Q, Current Report on Form 8-K or other report filed by the Company with the Commission, FINRA or any securities exchange.

(r) No Manipulation of Price. The Company will not take, directly or indirectly, any action designed to cause or result in, or that has constituted or might reasonably be expected to constitute, under the Exchange Act or otherwise, the stabilization or manipulation of the price of any securities of the Company to facilitate the sale or resale of the Securities.

(s) Investment Limitation. The Company shall not invest, or otherwise use the proceeds received by the Company from its sale of the Notes in such a manner as would require the Company or any of its subsidiaries to register as an investment company under the Investment Company Act.

(t) Notice of Inability to Use Automatic Shelf Registration Statement Form. If at any time during the Prospectus Delivery Period, the Company receives from the Commission a notice pursuant to Rule 401(g)(2) or otherwise ceases to be eligible to use the automatic shelf registration statement form, the Company will (i) promptly notify the Representative, (ii) promptly file a new registration statement or post-effective amendment

on the proper form relating to the Notes, in a form satisfactory to the Representative, (iii) use its best efforts to cause such registration statement or post-effective amendment to be declared effective and (iv) promptly notify the Representative of such effectiveness. The Company will take all other action necessary or appropriate to permit the public offering and sale of the Notes to continue as contemplated in the registration statement that was the subject of the Rule 401(g)(2) notice or for which the Company has otherwise become ineligible. References herein to the Registration Statement shall include such new registration statement or post-effective amendment, as the case may be.

5. Payment of Expenses. The Company and the Guarantors, jointly and severally, agree to pay all costs, fees and expenses incurred in connection with the performance of their obligations hereunder and in connection with the transactions contemplated hereby, including without limitation (i) all expenses incident to the issuance and delivery of the Securities (including all printing and engraving costs), (ii) all necessary issue, transfer and other stamp taxes in connection with the issuance and sale of the Securities to the Underwriters, (iii) all fees and expenses of the Company’s and the Guarantors’ counsel, independent public or certified public accountants and other advisors, (iv) all costs and expenses incurred in connection with the preparation, printing, filing, shipping and distribution of the Registration Statement (including financial statements, exhibits, schedules, consents and certificates of experts), each Issuer Free Writing Prospectus, each Preliminary Prospectus and the Prospectus, and all amendments and supplements thereto, and the mailing and delivering of copies thereof to the Underwriters and dealers, this Agreement, the Indenture, the DTC Agreement and the Notes and Guarantees, (v) all filing fees, attorneys’ fees and expenses incurred by the Company, the Guarantors or the Underwriters in connection with qualifying or registering (or obtaining exemptions from the qualification or registration of) all or any part of the Securities for offer and sale under the securities laws of the several states of the United States, the provinces of Canada or other jurisdictions designated by the Underwriters (including, without limitation, the cost of preparing, printing and mailing preliminary and final blue sky or legal investment memoranda, (vi) the fees and expenses of the Trustee, including the fees and disbursements of counsel for the Trustee in connection with the Indenture and the Securities, (vii) any fees payable in connection with the rating of the Securities with the ratings agencies, (viii) the filing fees for FINRA’s review of the offering of the Securities, and the reasonable fees and disbursements of counsel to the Underwriters in connection with compliance with FINRA’s rules and regulations, (ix) all fees and expenses (including reasonable fees and expenses of counsel) of the Company and the Guarantors in connection with approval of the Securities by DTC for “book-entry” transfer, and the performance by the Company and the Guarantors of their respective other obligations under this Agreement counsel and (x) all expenses incident to the “road show” for the offering of the Securities, including the cost of any chartered airplane or other transportation, (x) all other fees, costs and expenses referred to in Item 14 of Part II of the Registration Statement, and (xi) the fees and expenses of the QIU and (xii) all other costs and expenses incident to the performance of their obligations hereunder which are not otherwise specifically provided for in this Section 5. It is understood, however, that, except as provided in this Section 5, Section 7, Section 8 and Section 11 hereof, the Underwriters will pay all of their own costs and expenses, including the fees and expenses of their counsel.

6. Conditions to the Obligations of the Underwriters. The obligations of the Underwriters hereunder shall be subject, in their discretion, to the condition that all representations and warranties of the Company and each Guarantor herein are true and correct at and as of the date hereof and the Closing Date, the condition that the Company and each Guarantor shall have performed all of their respective obligations hereunder theretofore to be performed, and the following additional conditions:

(a) Accountants’ Comfort Letter. On the date hereof, the Underwriters shall have received from PricewaterhouseCoopers LLP, independent public accountants for the Company, a letter dated the date hereof addressed to the Underwriters, in form and substance satisfactory to the Representative, covering certain financial information included in or incorporated by reference in the Disclosure Package and other customary information.

(b) Independent Petroleum Consultants’ Letter. On the date hereof, the Representative shall have received from Ryder Scott Company L.P., independent petroleum consultants with respect to the Company and its subsidiaries, a letter dated the date hereof addressed to the Underwriters covering the reserve information included in or incorporated by reference in the Disclosure Package and other customary information, the form of which is attached as Exhibit A.

(c) Compliance with Registration Requirements; No Stop Order; No Objection from FINRA. For the period from and after effectiveness of this Agreement and prior to the Closing Date and, with respect to the Securities:

(i) the Company shall have filed the Prospectus with the Commission (including the information required by Rules 430A, 430B and 430C under the Securities Act) in the manner and within the time period required by Rule 424(b) under the Securities Act;

(ii) the Final Term Sheet, and any other material required to be filed by the Company pursuant to Rule 433(d) under the Securities Act, shall have been filed with the Commission within the applicable time periods prescribed for such filings under such Rule 433;

(iii) no stop order suspending the effectiveness of the Registration Statement, or any post-effective amendment to the Registration Statement, shall be in effect and no proceedings for such purpose or pursuant to Section 8A of the Securities Act shall have been instituted or threatened by the Commission; and the Company shall not have received from the Commission any notice pursuant to Rule 401(g)(2) of the Securities Act objecting to use of the automatic shelf registration statement form; and

(iv) FINRA shall have advised the Representative in writing that it has no objection to the underwriting and other terms and arrangements related to the offering of the Securities.

(d) No Material Adverse Change or Ratings Agency Change. For the period from and after the date of this Agreement and prior to the Closing Date:

(i) in the judgment of the Representative there shall not have occurred any Material Adverse Change;

(ii) there shall not have been any change or decrease specified in the letter or letters referred to in paragraph (a) of this Section 6 which is, in the sole judgment of the Representative, so material and adverse as to make it impractical or inadvisable to proceed with the offering, sale or delivery of the Securities as contemplated by this Agreement, the Disclosure Package and the Prospectus; and

(iii) there shall not have occurred any downgrading, nor shall any notice have been given of any intended or potential downgrading or of any review for a possible change that does not indicate the direction of the possible change, in the rating accorded the Company or any of its subsidiaries by any “nationally recognized statistical rating organization” as such term is defined for purposes of Rule 436(g)(2) under the Securities Act, and no such organization shall have publicly announced that it has under surveillance or review, with possible negative implications, any such rating.

(e) Opinion of Counsel for the Company and the Guarantors. On the Closing Date, the Underwriters shall have received the favorable opinion of Conner & Winters, LLP, counsel for the Company and the Guarantors, dated as of such Closing Date, the form of which is attached as Exhibit B.

(f) Opinion of General Counsel for the Company and the Guarantors. On the Closing Date, the Underwriters shall have received the favorable opinion of Mark E. Schell, General Counsel for the Company and the Guarantors, dated as of such Closing Date, the form of which is attached as Exhibit C.

(g) Opinion of Counsel for the Underwriters. On the Closing Date, the Underwriters shall have received the favorable opinion of Davis Polk & Wardwell LLP, counsel for the Underwriters, dated as of such Closing Date, in form and substance satisfactory to, and addressed to, the Underwriters, with respect to the issuance and sale of the Notes, the Registration Statement, the Prospectus (together with any supplement thereto), the Disclosure Package and other related matters as the Representative may reasonably require, and the Company shall have furnished to such counsel such documents as they reasonably request for the purpose of enabling them to pass upon such matters.

(h) Officers’ Certificate. On the Closing Date, the Representative shall have received a written certificate executed by the Chairman of the Board, Chief Executive Officer or President of the Company and each Guarantor and the Chief Financial Officer or Chief Accounting Officer of the Company and each Guarantor, dated as of the Closing Date, to the effect that the signers of such certificate have carefully examined the Registration Statement, the Disclosure Package, the Prospectus and any amendment or supplement thereto, any Issuer Free Writing Prospectus and any amendment or supplement thereto and this Agreement, to the effect set forth in subsections (c) and (d)(iii) of this Section 6, and further to the effect that:

(i) for the period from and after the date of this Agreement and prior to the Closing Date, there has not occurred any Material Adverse Change;

(ii) the representations and warranties of the Company and each respective Guarantor set forth in Section 1(a) of this Agreement are true and correct on and as of the Closing Date with the same force and effect as though expressly made on and as of the Closing Date; and

(iii) the Company and each respective Guarantor has complied with all the agreements hereunder and satisfied all the conditions on its respective part to be performed or satisfied hereunder at or prior to the Closing Date.

(i) Bring-down Comfort Letter. On the Closing Date, the Underwriters shall have received from PricewaterhouseCoopers LLP, independent public accountants for the Company, a letter dated such date, in form and substance satisfactory to the Representative, to the effect that they reaffirm the statements made in the letter furnished by them pursuant to subsection (a) of this Section 6, except that (i) it shall cover certain financial information included in or incorporated by reference to the Prospectus and any amendment or supplement thereto and (ii) the specified date referred to therein for the carrying out of procedures shall be no more than three business days prior to the Closing Date, as the case may be.

(j) Bring-down Independent Petroleum Consultants’ Letter. On the Closing Date, the Representative shall have received from Ryder Scott Company L.P., independent petroleum consultants with respect to the Company and its subsidiaries, a letter dated such date, in form and substance satisfactory to the Representative, to the effect that they reaffirm the statements made in the letter furnished by them pursuant to subsection (b) of this Section 6, except that it shall cover the reserve information included in or incorporated by reference to the Prospectus and any amendment or supplement thereto.

(k) Form of Securities and Indenture. The Securities and the Indenture shall be executed by the Company, or the Guarantors, as the case may be, in form and substance reasonably satisfactory to the Representative and the Trustee.

(l) Closing Documents. At the Closing Date, the Company and the Guarantors shall have furnished counsel for the Company, the Guarantors or the Underwriters, as the case may be, such documents as they reasonably require for the purpose of enabling them to pass upon the issuance and sale of the Securities as herein contemplated, or in order to evidence the accuracy of any of the representations or warranties or fulfillment of any of the conditions herein contained.

If any condition specified in this Section 6 is not satisfied when and as required to be satisfied, this Agreement may be terminated by the Representative by notice to the Company

at any time on or prior to the Closing Date, which termination shall be without liability on the part of any party to any other party, except that Section 5, Section 7, Section 8, Section 9, Section 13 and Section 17 shall at all times be effective and shall survive such termination.

(a) If this Agreement is terminated by the Representative pursuant to Section 6, Section 10 or Section 11, or if the sale to the Underwriters of the Notes on the Closing Date is not consummated because of any refusal, inability or failure on the part of the Company or any Guarantor to perform any agreement herein or to comply with any provision hereof, the Company and the Guarantors, jointly and severally, agree to reimburse the Representative and the other Underwriters (or such Underwriters as have terminated this Agreement with respect to themselves) but not any defaulting Underwriters under Section 10 in the case that this Agreement is terminated pursuant to Section 10, severally, upon demand for all out-of-pocket expenses that shall have been reasonably incurred by the Representative and the Underwriters in connection with the proposed purchase and the offering and sale of the Securities, including but not limited to fees and disbursements of counsel, printing expenses, travel expenses, postage, facsimile and telephone charges.

(a) Indemnification of the Underwriters. The Company and the Guarantors agree, jointly and severally, to indemnify and hold harmless each Underwriter, its directors, officers, employees, agents and affiliates, and each person, if any, who controls any Underwriter within the meaning of the Securities Act and the Exchange Act against any loss, claim, damage, liability or expense, as incurred, to which such Underwriter or such controlling person may become subject, insofar as such loss, claim, damage, liability or expense (or actions in respect thereof as contemplated below) arises out of or is based (i) upon any untrue statement or alleged untrue statement of a material fact contained in the Registration Statement, or any amendment thereto, including any information deemed to be a part thereof pursuant to Rule 430B or 430C under the Securities Act, or the omission or alleged omission therefrom of a material fact required to be stated therein or necessary to make the statements therein not misleading; or (ii) upon any untrue statement or alleged untrue statement of a material fact contained in any Issuer Free Writing Prospectus, any Preliminary Prospectus or the Prospectus (or any amendment or supplement thereto), or the omission or alleged omission therefrom of a material fact, in each case, necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading, and to reimburse each Underwriter, its officers, directors, employees, agents and each such controlling person for any and all expenses (including, subject to Section 8(c), the fees and disbursements of counsel chosen by Merrill Lynch) as such expenses are reasonably incurred by such Underwriter, or its officers, directors, employees and agents or such controlling person in connection with investigating, defending, settling, compromising or paying any such loss, claim, damage, liability, expense or action; provided, however, that the foregoing indemnity agreement shall not apply to any loss, claim, damage, liability or expense to the extent, but only to the extent, arising out of or based upon any untrue statement or alleged untrue statement or omission or alleged omission made in reliance upon and in conformity with written information furnished to the Company by the Representative expressly for use in the Registration Statement, any Issuer Free Writing Prospectus, any Preliminary Prospectus or the Prospectus (or any amendment or supplement thereto). The indemnity agreement set forth in this Section 8(a) shall be in addition to any liabilities that the Company may otherwise have.

(b) Indemnification of the Company and the Guarantors, Directors and Officers. Each Underwriter agrees, severally and not jointly, to indemnify and hold harmless the Company and the Guarantors, each of their respective directors and officers and each person, if any, who controls the Company or any of the Guarantors within the meaning of the Securities Act or the Exchange Act, against any loss, claim, damage, liability or expense, as incurred, to which the Company, or any such director, officer or controlling person may become subject, insofar as such loss, claim, damage, liability or expense (or actions in respect thereof as contemplated below) arises out of or is based upon any untrue or alleged untrue statement of a material fact contained in the Registration Statement, any Issuer Free Writing Prospectus, any Preliminary Prospectus or the Prospectus (or any amendment or supplement thereto), or arises out of or is based upon the omission or alleged omission to state therein a material fact required to be stated therein (in the case of the Registration Statement) or necessary to make the statements therein not misleading, in each case to the extent, and only to the extent, that such untrue statement or alleged untrue statement or omission or alleged omission was made in the Registration Statement, any Issuer Free Writing Prospectus, any Preliminary Prospectus or the Prospectus (or any amendment or supplement thereto), in reliance upon and in conformity with written information furnished to the Company by any Underwriter through the Representative expressly for use therein; and to reimburse the Company and the Guarantors, or any such director, officer or controlling person for any legal and other expense reasonably incurred by the Company and the Guarantors, or any such director, officer or controlling person in connection with investigating, defending, settling, compromising or paying any such loss, claim, damage, liability, expense or action. The Company and the Guarantors hereby acknowledge that the only information that the Underwriters have furnished to the Company through the Representative expressly for use in the Registration Statement, any Issuer Free Writing Prospectus, any Preliminary Prospectus or the Prospectus (or any amendment or supplement thereto) are the statements set forth in the following paragraphs under the caption “Underwriting” in the Prospectus: 5th and 10th. The indemnity agreement set forth in this Section 8(b) shall be in addition to any liabilities that each Underwriter may otherwise have.

(c) Notifications and Other Indemnification Procedures. Promptly after receipt by an indemnified party under this Section 8 of notice of the commencement of any action, such indemnified party will, if a claim in respect thereof is to be made against an indemnifying party under this Section 8, notify the indemnifying party in writing of the commencement thereof; but the failure to so notify the indemnifying party (i) will not relieve it from liability under paragraph (a) or (b) above unless and to the extent it did not otherwise learn of such action and such failure results in the forfeiture by the indemnifying party of, or material prejudice its ability to assert, substantial rights and defenses and (ii) will not, in any event, relieve the indemnifying party from any obligations to any indemnified party other than the indemnification obligation provided in paragraph (a) or (b) above. In case any such action is brought against any indemnified party and such indemnified party seeks or intends to seek indemnity from an indemnifying party, the indemnifying party will be entitled to participate in, and, to the extent that it shall elect, jointly with all other indemnifying parties similarly notified, by written notice delivered to the indemnified party promptly after receiving the aforesaid notice from such indemnified party, to

assume the defense thereof with counsel satisfactory to such indemnified party; provided, however, if the defendants in any such action include both the indemnified party and the indemnifying party and the indemnified party shall have reasonably concluded that a conflict may arise between the positions of the indemnifying party and the indemnified party in conducting the defense of any such action or that there may be legal defenses available to it and/or the other indemnified parties that are different from or additional to those available to the indemnifying party, the indemnified party or parties shall have the right to select separate counsel to assume such legal defenses and to otherwise participate in the defense of such action on behalf of such indemnified party or parties. Upon receipt of notice from the indemnifying party to such indemnified party of such indemnifying party’s election so to assume the defense of such action and approval by the indemnified party of counsel, the indemnifying party will not be liable to such indemnified party under this Section 8 for any legal or other expenses subsequently incurred by such indemnified party in connection with the defense thereof unless (i) the indemnified party shall have employed separate counsel in accordance with the proviso to the preceding sentence (it being understood, however, that the indemnifying party shall not be liable for the expenses of more than one separate counsel (other than local counsel), reasonably approved by the indemnifying party (or by Merrill Lynch in the case of Section 8(b)), representing all indemnified parties who are parties to such action) or (ii) the indemnifying party shall not have employed counsel satisfactory to the indemnified party to represent the indemnified party within a reasonable time after notice of commencement of the action, in each of which cases the fees and expenses of counsel shall be at the expense of the indemnifying party.

(d) Settlements. The indemnifying party under this Section 8 shall not be liable for any settlement of any proceeding effected without its written consent, which shall not be withheld unreasonably, but if settled with such consent or if there be a final judgment for the plaintiff, the indemnifying party agrees to indemnify the indemnified party against any loss, claim, damage, liability or expense by reason of such settlement or judgment. No indemnifying party shall, without the prior written consent of the indemnified party, effect any settlement, compromise or consent to the entry of judgment in any pending or threatened action, suit or proceeding in respect of which any indemnified party is or could have been a party and indemnity was or could have been sought hereunder by such indemnified party, unless such settlement, compromise or consent (i) includes an unconditional release of such indemnified party from all liability on claims that are the subject matter of such action, suit or proceeding and (ii) does not include a statement as to or an admission of fault, culpability or a failure to act, by or on behalf of any indemnified party.

(e) Indemnification of the QIU. Without limitation and in addition to its obligation under the other subsections of this Section 8, the Company agrees to indemnify and hold harmless the QIU, its officers and employees and each person, if any, who controls the QIU within the meaning of the Securities Act or the Exchange Act from and against any loss, claim, damage, liabilities or expense, as incurred, arising out of or based upon the QIU’s acting as a “qualified independent underwriter” (within the meaning of FINRA Rule 5121(f)(12)) in connection with the offering contemplated by this Agreement, and agrees to reimburse each such indemnified person for any legal or other expense reasonably incurred by it in connection with investigating, defending, settling, compromising or paying any such loss, claim, damage, liability, expense or action; provided, however, that the Company shall not be liable in any such case to the extent that any such loss, claim, damage, liability or expense results from the gross negligence or willful misconduct of the QIU.

(a) If the indemnification provided for in Section 8 is for any reason unavailable to or otherwise insufficient to hold harmless an indemnified party in respect of any losses, claims, damages, liabilities or expenses referred to therein, then each indemnifying party shall contribute to the aggregate amount paid or payable by such indemnified party, as incurred, as a result of any losses, claims, damages, liabilities or expenses referred to therein (i) in such proportion as is appropriate to reflect the relative benefits received by the Company and the Guarantors, on the one hand, and the Underwriters, on the other hand, from the offering of the Securities pursuant to this Agreement or (ii) if the allocation provided by clause (i) above is not permitted by applicable law, in such proportion as is appropriate to reflect not only the relative benefits referred to in clause (i) above but also the relative fault of the Company and the Guarantors, on the one hand, and the Underwriters, on the other hand, in connection with the statements or omissions or inaccuracies in the representations and warranties herein which resulted in such losses, claims, damages, liabilities or expenses, as well as any other relevant equitable considerations. The relative benefits received by the Company and the Guarantors, on the one hand, and the Underwriters, on the other hand, in connection with the offering of the Securities pursuant to this Agreement shall be deemed to be in the same respective proportions as the total net proceeds from the offering of the Securities pursuant to this Agreement (before deducting expenses) received by the Company and the Guarantors, and the total underwriting discount received by the Underwriters, in each case as set forth on the front cover page of the Prospectus bear to the aggregate initial public offering price of the Securities as set forth on such cover. The relative fault of the Company and the Guarantors, on the one hand, and the Underwriters, on the other hand, shall be determined by reference to, among other things, whether any such untrue or alleged untrue statement of a material fact or omission or alleged omission to state a material fact or any such inaccurate or alleged inaccurate representation or warranty relates to information supplied by the Company and the Guarantors, on the one hand, or the Underwriters, on the other hand, and the parties’ relative intent, knowledge, access to information and opportunity to correct or prevent such statement or omission.

The amount paid or payable by a party as a result of the losses, claims, damages, liabilities and expenses referred to above shall be deemed to include, subject to the limitations set forth in Section 8(c), any legal or other fees or disbursements reasonably incurred by such party in connection with investigating or defending any action or claim.

The Company and the Underwriters agree that it would not be just and equitable if contribution pursuant to this Section 9 were determined by pro rata allocation (even if the Underwriters were treated as one entity for such purpose) or by any other method of allocation which does not take account of the equitable considerations referred to in this Section 9.

Notwithstanding the provisions of this Section 9, no Underwriter shall be required to contribute any amount in excess of the underwriting commissions received by such Underwriter in connection with the Securities underwritten by it and distributed to the public. No person guilty of fraudulent misrepresentation (within the meaning of Section 11(f) of the Securities

Act) shall be entitled to contribution from any person who was not guilty of such fraudulent misrepresentation. The Underwriters’ obligations to contribute pursuant to this Section 9 are several, and not joint, in proportion to their respective underwriting commitments as set forth opposite their names in Schedule A. For purposes of this Section 9, each director, officer, employee and agent of an Underwriter and each person, if any, who controls an Underwriter within the meaning of the Securities Act and the Exchange Act shall have the same rights to contribution as such Underwriter, and each director of the Company or a Guarantor, each officer of the Company or a Guarantor who signed the Registration Statement and each person, if any, who controls the Company or a Guarantor within the meaning of the Securities Act and the Exchange Act shall have the same rights to contribution as the Company and the Guarantors.

(a) If, on the Closing Date, any one or more of the several Underwriters shall fail or refuse to purchase Securities that it or they have agreed to purchase hereunder on such date, and the aggregate principal amount of Securities which such defaulting Underwriter or Underwriters agreed but failed or refused to purchase does not exceed 10% of the aggregate principal amount of the Securities to be purchased on such date, the other Underwriters shall be obligated, severally, in the proportions that the principal amount of Securities to be purchased set forth opposite their respective names on Schedule A bears to the aggregate principal amount of Securities set forth opposite the names of all such non-defaulting Underwriters, or in such other proportions as may be specified by the Representative with the consent of the non-defaulting Underwriters, to purchase the Securities which such defaulting Underwriter or Underwriters agreed but failed or refused to purchase on such date. If, on the Closing Date, any one or more of the Underwriters shall fail or refuse to purchase Securities and the principal amount of Securities with respect to which such default occurs exceeds 10% of the principal amount of Securities to be purchased on such date, and arrangements satisfactory to the Representative and the Company for the purchase of such Securities are not made within 48 hours after such default, this Agreement shall terminate without liability of any party to any other party except that the provisions of Section 5, Section 7, Section 8, Section 9, Section 13 and Section 17 shall at all times be effective and shall survive such termination. In any such case either the Representative or the Company shall have the right to postpone the Closing Date, but in no event for longer than seven days in order that the required changes, if any, to the Registration Statement, any Issuer Free Writing Prospectus, the Preliminary Prospectus or the Prospectus or any other documents or arrangements may be effected. As used in this Agreement, the term “Underwriter” shall be deemed to include any person substituted for a defaulting Underwriter under this Section 10. Any action taken under this Section 10 shall not relieve any defaulting Underwriter from liability in respect of any default of such Underwriter under this Agreement.

(a) Prior to the Closing Date this Agreement may be terminated by the Representative by notice given to the Company if at any time (i) trading or quotation in any of the Company’s securities shall have been suspended or limited by the Commission or trading in securities generally on the New York Stock Exchange shall have been suspended or limited, or minimum or maximum prices shall have been generally established on such stock exchange by the Commission or the FINRA; (ii) a general banking moratorium shall have been declared by

federal or New York authorities or a material disruption in commercial banking or securities settlement or clearance services in the United States has occurred; (iii) in the judgment of the Representative there shall have occurred any Material Adverse Change; or (iv) there shall have occurred any outbreak or escalation of national or international hostilities or any crisis or calamity, or any change in the United States or international financial markets, or any substantial change or development involving a prospective substantial change in United States’ or international political, financial or economic conditions, as in the judgment of the Representative is material and adverse and makes it impracticable or inadvisable to market the Securities in the manner and on the terms described in the Disclosure Package or the Prospectus or to enforce contracts for the sale of securities. Any termination pursuant to this Section 11 shall be without liability on the part of (a) the Company or any Guarantor to any Underwriter, except that the Company shall be obligated to reimburse the expenses of the Representative and the Underwriters pursuant to Sections 5, 7, 8 and 9 hereof or (b) any Underwriter to the Company.

(a) The Company and each Guarantor acknowledge and agree that: (i) the purchase and sale of the Securities pursuant to this Agreement, including the determination of the public offering price of the Securities and any related discounts and commissions, is an arm’s-length commercial transaction between the Company and such Guarantor, on the one hand, and the several Underwriters, on the other hand, and the Company and such Guarantor are capable of evaluating and understanding and understand and accept the terms, risks and conditions of the transactions contemplated by this Agreement; (ii) in connection with each transaction contemplated hereby and the process leading to such transaction each Underwriter is and has been acting solely as a principal and is not the financial advisor, agent or fiduciary of the Company, the Guarantors or any of their respective affiliates, stockholders, creditors or employees or any other party; (iii) no Underwriter has assumed or will assume an advisory, agency or fiduciary responsibility in favor of the Company or such Guarantor with respect to any of the transactions contemplated hereby or the process leading thereto (irrespective of whether such Underwriter has advised or is currently advising the Company or such Guarantor on other matters) and no Underwriter has any obligation to the Company or such Guarantor with respect to the offering contemplated hereby except the obligations expressly set forth in this Agreement; (iv) the several Underwriters and their respective affiliates may be engaged in a broad range of transactions that involve interests that differ from those of the Company and the Guarantors and that the several Underwriters have no obligation to disclose any of such interests by virtue of any advisory, agency or fiduciary relationship; and (v) the Underwriters have not provided any legal, accounting, regulatory or tax advice with respect to the offering contemplated hereby and the Company and the Guarantors have consulted their own legal, accounting, regulatory and tax advisors to the extent they deemed appropriate.

This Agreement supersedes all prior agreements and understandings (whether written or oral) between the Company, the Guarantors and the several Underwriters, or any of them, with respect to the subject matter hereof. The Company and each Guarantor hereby waive and release, to the fullest extent permitted by law, any claims that the Company or such Guarantor may have against the several Underwriters with respect to any breach or alleged breach of agency or fiduciary duty.

13. Representations and Indemnities to Survive Delivery. The respective indemnities, agreements, representations, warranties and other statements of the Company, of its officers and of the several Underwriters set forth in or made pursuant to this Agreement will remain operative and in full force and effect, regardless of any (A) investigation, or statement as to the results thereof, made by or on behalf of any Underwriter, the QIU, the officers or employees of any Underwriter or the QIU, or any person controlling the Underwriter or the QIU or (B) acceptance of the Securities and payment for them hereunder. The provisions of Section 5, Section 7, Section 8, Section 9, this Section 13 and Section 17 hereof shall survive the termination or cancellation of this Agreement.

14. Notices. All communications hereunder shall be in writing and shall be mailed, hand delivered or telecopied and confirmed to the parties hereto as follows:

Attention: David Merrill, Chief Financial Officer and Treasurer, with a copy to Mark Schell, Senior Vice President, General Counsel and Secretary

Any party hereto may change the address for receipt of communications by giving written notice to the others.

15. Successors and Assigns. This Agreement will inure to the benefit of and be binding upon the parties hereto, including any substitute Underwriters pursuant to Section 10 hereof, and to the benefit of (i) the Company and the Guarantors, their respective directors, any person who controls the Company or any of the Guarantors within the meaning of the Securities Act and the Exchange Act and any officer of the Company or any Guarantor who signed the Registration Statement, (ii) the Underwriters, the officers, directors, employees and agents of the Underwriters, and each person, if any, who controls any Underwriter within the meaning of the Securities Act and the Exchange Act, (iii) the QIU, the QIU’s officers, directors, employees and agents, and each person, if any, who controls the QIU within the meaning of the Securities Act and the Exchange Act, and (iii) the respective successors and assigns of any of the above, all as and to the extent provided in this Agreement, and no other person shall acquire or have any right under or by virtue of this Agreement. The term “successors and assigns” shall not include a purchaser of any of the Securities from any of the several Underwriters merely because of such purchase.

16. Partial Unenforceability. The invalidity or unenforceability of any Section, paragraph or provision of this Agreement shall not affect the validity or enforceability of any other Section, paragraph or provision hereof. If any Section, paragraph or provision of this Agreement is for any reason determined to be invalid or unenforceable, there shall be deemed to be made such minor changes (and only such minor changes) as are necessary to make it valid and enforceable.

17. Governing Law Provisions. THIS AGREEMENT SHALL BE GOVERNED BY, AND CONSTRUED AND INTERPRETED IN ACCORDANCE WITH THE LAW OF THE STATE OF NEW YORK.

(a) Consent to Jurisdiction. Any legal suit, action or proceeding arising out of or based upon this Agreement or the transactions contemplated hereby (“Related Proceedings”) may be instituted in the federal courts of the United States of America located in the City and County of New York or the courts of the State of New York in each case located in the City and County of New York (collectively, the “Specified Courts”), and each party irrevocably submits to the jurisdiction (including suits, actions, or proceedings instituted in regard to the enforcement of a judgment of any Specified Court in a Related Proceeding (a “Related Judgment”)) of the Specified Courts in any Related Proceeding. Service of any process, summons, notice or document by mail to such party’s address set forth above shall be effective service of process for any Related Proceeding brought in any Specified Court. The parties irrevocably and unconditionally waive any objection to the laying of venue of any Related Proceeding in the Specified Courts and irrevocably and unconditionally waive and agree not to plead or claim in any Specified Court that any Related Proceeding brought in any Specified Court has been brought in an inconvenient forum.

(b) Waiver of Immunity. With respect to any Related Proceeding, each party irrevocably waives, to the fullest extent permitted by applicable law, all immunity (whether on the basis of sovereignty or otherwise) from jurisdiction, service of process, attachment (both before and after judgment) and execution to which it might otherwise be entitled in the Specified Courts, and with respect to any Related Judgment, each party waives any such immunity in the Specified Courts or any other court of competent jurisdiction, and will not raise or claim or cause to be pleaded any such immunity at or in respect of any such Related Proceeding or Related Judgment, including, without limitation, any immunity pursuant to the United States Foreign Sovereign Immunities Act of 1976, as amended.

18. General Provisions. This Agreement constitutes the entire agreement of the parties to this Agreement and supersedes all prior written or oral and all contemporaneous oral agreements, understandings and negotiations with respect to the subject matter hereof. This Agreement may be executed in two or more counterparts, each one of which shall be an original, with the same effect as if the signatures thereto and hereto were upon the same instrument. Delivery of an executed counterpart of a signature page to this Agreement by telecopier, facsimile, email or other electronic transmission (i.e., “pdf” or “tif”) shall be effective as delivery of a manually executed counterpart of this Agreement. This Agreement may not be amended or modified unless in writing by all of the parties hereto, and no condition herein (express or implied) may be waived unless waived in writing by each party whom the condition is meant to benefit. The Section headings herein are for the convenience of the parties only and shall not affect the construction or interpretation of this Agreement.

Each of the parties hereto acknowledges that it is a sophisticated business person who was adequately represented by counsel during negotiations regarding the provisions hereof, including, without limitation, the indemnification provisions of Section 8 and the contribution provisions of Section 9, and is fully informed regarding said provisions. Each of the parties hereto further acknowledges that the provisions of Sections 8 and 9 hereto fairly allocate the risks in light of the ability of the parties to investigate the Company, its affairs and its business in order to assure that adequate disclosure has been made in the Registration Statement, the Disclosure Package and the Prospectus (and any amendments and supplements thereto), as required by the Securities Act and the Exchange Act.

If the foregoing is in accordance with your understanding of our agreement, kindly sign and return to the Company the enclosed copies hereof, whereupon this instrument, along with all counterparts hereof, shall become a binding agreement in accordance with its terms.


Very truly yours,

UNIT CORPORATION

By:		/s/ Mark E. Schell
Name:		Mark E. Schell
Title:		Senior Vice President

UNIT DRILLING COMPANY
UNIT PETROLEUM COMPANY
UNIT TEXAS COMPANY
UNIT DRILLING AND EXPLORATION COMPANY
PETROLEUM SUPPLY COMPANY

By:		/s/ Mark E. Schell
Name:		Mark E. Schell
Title:		Senior Vice President

UNIT DRILLING USA COLOMBIA, L.L.C.
UNIT DRILLING COLOMBIA, L.L.C.

By:		/s/ Mark E. Schell
Name:		Mark E. Schell
Title:		Manager


UNIT TEXAS DRILLING, L.L.C.
PRESTON COUNTY GAS GATHERING, L.L.C.

By:		/s/ Mark E. Schell
Name:		Mark E. Schell
Title:		Manager

By:		/s/ Larry D. Pinkston
Name:		Larry D. Pinkston
Title:		Manager

SUPERIOR PIPELINE COMPANY, L.L.C.
SUPERIOR PIPELINE TEXAS, L.L.C.
SUPERIOR APPALACHIAN PIPELINE, L.L.C.

By:		/s/ Mark E. Schell
Name:		Mark E. Schell
Title:		Manager

By:		/s/ Larry D. Pinkston
Name:		Larry D. Pinkston
Title:		Manager

By:		/s/ Robert H. Parks
Name:		Robert H. Parks
Title:		Manager

The foregoing Agreement is hereby confirmed and accepted by the Representative as of the date first above written.

The Pricing Supplement, dated May 11, 2011, to the Preliminary Prospectus Supplement, dated May 3, 2011, a copy of which appears below.

This Pricing Supplement is qualified in its entirety by reference to the Preliminary Prospectus Supplement dated May 3, 2011. The information in this Pricing Supplement supplements the Preliminary Prospectus Supplement and supersedes the information in the Preliminary Prospectus Supplement to the extent inconsistent with the information in the Preliminary Prospectus Supplement. Capitalized terms used but not defined in this Pricing Supplement have the respective meanings ascribed to them in the Preliminary Prospectus Supplement.

The following disclosure under “Use of Proceeds” on page S-31 and each other location where such information appears in the Preliminary Prospectus Supplement is amended to read as follows:

We expect the net proceeds from this offering to be approximately $244 million, after deducting estimated fees and expenses (including underwriting discounts and commissions). We intend to use the net proceeds from this offering to repay outstanding borrowings under our credit facility and for general corporate purposes. At March 31, 2011, borrowings under our credit facility were $185.0 million. Amounts to be repaid were incurred for general corporate purposes, including to fund our capital expenditure program, and may be

reborrowed from time to time. Our credit facility matures on May 24, 2012, and the average annual interest rate for 2010 and the first three months of 2011, which includes the effect of interest rate swaps, was 3.5% and 2.8%, respectively.

The following disclosure under “Description of the Notes – Ranking and subordination” on page S-99 and each other location where such information appears in the Preliminary Prospectus Supplement is amended to read as follows:

Assuming that we had applied the net proceeds we receive from the offering in the manner described under “Use of proceeds,” as of March 31, 2011:

There was a typographical error transposing three lines under “Summary – Summary Historical Consolidated Financial Data” on page S-10. The disclosure is amended in that section and each other location where such information appears in the Preliminary Prospectus Supplement as follows: for “Oil and natural gas - Impairment of oil and natural gas properties,” the correct data is $0 for the three months ended March 31, 2011 and $0 for the three months ended March 31, 2010; for “Gas gathering and processing – operating costs,” the correct data is $29,055,000 for the three months ended March 31, 2011 and $32,726,000 for the three months ended March 31, 2010; and for “Gas gathering and processing – Depreciation and amortization,” the correct data is $3,773,000 for the three months ended March 31, 2011 and $3,941,000 for the three months ended March 31, 2010.

Other information (including financial information) presented in the Preliminary Prospectus Supplement is deemed to have changed to the extent effected by the changes described herein.

The Company has filed a registration statement (including a prospectus) with the SEC for the offering to which this communication relates. Before you invest, you should read the prospectus in that registration statement and other documents the Company has filed with the SEC for more complete information about the Company and this offering. You may get these documents for free by visiting EDGAR on the SEC Web site at www.sec.gov. Alternatively, the Company, any underwriter or any dealer participating in the offering will arrange to send you the prospectus if you send a request to: BofA Merrill Lynch, 4 World Financial Center, New York, NY 10080, Attention: Preliminary Prospectus Department, or email Prospectus.Requests@ml.com.

This letter, which is written at the request of Unit Corporation (the “Company”), is being delivered to the Underwriters pursuant to the terms of an underwriting agreement between the Company and the Underwriters relating to the offering of $ aggregate principal amount of the Company’s senior subordinated notes due , which are being offered by the Company pursuant to the prospectus supplement dated (the “Prospectus”). Our report letter dated as of December 31, 2010 to the Company presented the Company’s estimates of Proved Reserves, attributable to interests of the Company as of December 31, 2010 (the “2010 Report”). In addition, we also delivered previous reports to the Company for the years ended December 31, 2009 and 2008 (the “Previous Reports”). The 2010 Report and the Previous Reports are collectively referred to in this letter as the “Reports.”

We hereby consent to the references to our firm and the use of the Reports as set forth in the Prospectus. This letter is solely for the information of the addressees and to assist the addressees in documenting their investigations in connection with the offering of the securities covered by the Prospectus.

Opinion of counsel for the Company and the Guarantors to be delivered pursuant to Section 6(e) of the Underwriting Agreement.

References to the Prospectus in this Exhibit A include any supplements thereto at the Closing Date.

(i) Each of the Company and the Guarantors has been duly incorporated or formed, as applicable, and is validly existing as a corporation or limited liability company in good standing under the laws of the State of Delaware or the State of Oklahoma, as applicable.

(ii) Each of the Company and the Guarantors has the requisite corporate or limited liability company power and authority to own or lease, as the case may be, its properties and to conduct its business as described in the Disclosure Package and the Prospectus and to enter into and perform its obligations under the Underwriting Agreement.

(iii) Each of the Company and the Guarantors is duly qualified as a foreign corporation to transact business and is in good standing in those jurisdictions listed on a schedule or exhibit to such opinion.

(iv) All of the issued and outstanding capital stock of each corporate Guarantor has been duly authorized and validly issued, is fully paid and non-assessable and is owned by the Company, directly or through subsidiaries, free and clear of any security interest, mortgage, pledge, lien, encumbrance or, to the best knowledge of such counsel, any pending or threatened claim.

(v) All of the issued and outstanding limited liability company interest of each limited liability company Guarantor has been duly authorized and validly issued and is owned by the Company, directly or through subsidiaries, free and clear of any security interest, mortgage, pledge, lien, encumbrance or, to the best knowledge of such counsel, any pending or threatened claim.

(vi) The Underwriting Agreement has been duly authorized, executed and delivered by the Company and the Guarantors.

(vii) The Indenture has been duly authorized, executed and delivered by the Company and each Guarantor and (assuming the due authorization, execution and delivery thereof by the Trustee) constitutes a valid and binding agreement of the Company and each Guarantor, enforceable against the Company and each Guarantor in accordance with its terms, except as the enforcement thereof may be limited by bankruptcy, insolvency, reorganization, moratorium or other similar laws relating to or affecting enforcement of the rights and remedies of creditors or by general principles of equity.

(viii) The Notes are in the form contemplated by the Indenture, have been duly authorized and executed by the Company and, when authenticated by the Trustee in the manner provided in the Indenture (assuming the due authorization, execution and delivery of the Indenture by the Trustee) and delivered against payment of the purchase price therefor in accordance with the Underwriting Agreement, will constitute valid and binding obligations of the Company, enforceable against the Company in accordance with their terms, except as the enforcement thereof may be limited by bankruptcy, insolvency, reorganization, moratorium, or similar laws relating to or affecting enforcement of the rights and remedies of creditors or by general principles of equity and will be entitled to the benefits of the Indenture.

(ix) The notations of Guarantee are in the form contemplated by the Indenture, have been duly authorized and executed by the Guarantors and, when the Notes are authenticated by the Trustee in the manner provided in the Indenture (assuming the due authorization, execution and delivery of the Indenture by the Trustee) and delivered against payment of the purchase price therefor, will constitute valid and binding obligations of the Guarantors, enforceable against the Guarantors in accordance with their terms, except as the enforcement thereof may be limited by bankruptcy, insolvency, reorganization, moratorium, or similar laws relating to or affecting enforcement of the rights and remedies of creditors or by general principles of equity and will be entitled to the benefits of the Indenture.

(x) The statements in the Preliminary Prospectus and the Prospectus under the captions “Description of Other Indebtedness,” “Description of the Notes,” “Business—Regulation,” and “Certain United States Federal Income Tax Considerations” insofar as such statements constitute matters or summaries of law, the Company’s charter or by-law provisions, documents or legal proceedings, or legal conclusions, have been reviewed by such counsel and fairly present and summarize, in all material respects, the matters referred to therein.

(xi) The Registration Statement has become effective under the Securities Act and is an “automatic shelf registration statement” as defined in Rule 405 of the Securities Act that has been filed with the Commission not earlier than three years prior to the Closing Date. To the best knowledge of such counsel, no stop order suspending the effectiveness of the Registration Statement or any post-effective amendment to the Registration Statement is in effect and no proceedings for such purpose pursuant to Section 8A of the Securities Act have been instituted or are pending or are threatened by the Commission and the Company has not received from the Commission any notice pursuant to Rule 401(g)(2) of the Securities Act objecting to use of the automatic shelf registration statement form. Any required filing of the Preliminary Prospectus and the Prospectus pursuant to Rule 424(b) of the Securities Act has been made in the manner and within the time period required by Rule 424(b) of the Securities Act. Any required filing of the Final Term Sheet and any other “issuer free writing prospectus” mutually expressly agreed by the Company and you pursuant to Section 4 of the Underwriting Agreement to be used by the Company and of which such counsel has actual knowledge has been made in the manner and within the time period required by Rule 433 of the Securities Act.

(xii) The Registration Statement and the Prospectus and each amendment or supplement to the Registration Statement and the Prospectus, as of their respective effective or issue dates (other than the financial statements and supporting schedules, estimated oil and natural gas

reserve estimations and related calculations, and other financial or related statistical information or data and assessments of or reports on the effectiveness of internal control over financial reporting included or incorporated by reference therein or in exhibits to or excluded from the Registration Statement, and the Trustee’s Statement of Eligibility on Form T-1, as to which no opinion need be rendered) comply as to form in all material respects with the applicable requirements of the Securities Act.

(xiii) Each document filed pursuant to the Exchange Act (other than the financial statements and supporting schedules, estimated oil and natural gas reserve estimations and related calculations, and assessments of or reports on the effectiveness of internal control over financial reporting included therein, as to which no opinion need be rendered) and incorporated or deemed to be incorporated by reference in the Prospectus complied when so filed as to form in all material respects with the Exchange Act.

(xiv) To the knowledge of such counsel, there are no legal or governmental actions, suits or proceedings pending or threatened to which the Company or any of its subsidiaries is a party or of which any property or assets of the Company or any of its subsidiaries is the subject, which are required to be disclosed in the Registration Statement, other than those disclosed therein or in the Disclosure Package and the Prospectus.

(xv) No consent, approval, authorization or other order of, or registration or filing with, any court or other governmental authority or agency, is required for the Company’s or any Guarantor’s execution, delivery and performance of the Underwriting Agreement, the Indenture and the Securities and the consummation of the transactions contemplated thereby and by the Prospectus and the Disclosure Package, except as required under the Securities Act, the Exchange Act, applicable state securities or blue sky laws and from FINRA.

(xvi) The issuance and sale of the Securities, execution and delivery of the Underwriting Agreement and the Indenture by the Company and the Guarantors, the performance by the Company and the Guarantors of their obligations thereunder and the consummation of the transactions contemplated therein (i) will not result in any violation of the provisions of the charter, bylaws or similar organizational document of the Company or any Guarantor; (ii) will not constitute a material Default or a Debt Repayment Triggering Event under, or result in the creation or imposition of any material lien, charge or encumbrance upon any property or assets of the Company or any of its subsidiaries under any of the Existing Instruments listed in a schedule or exhibit to such opinion to which the Company or any of its subsidiaries is a party or by which it or any of them may be bound; (iii) will not result in any violation of any statute, law, rule, applicable to the Company or any of its subsidiaries which in the experience of such counsel would normally apply to transactions of the type contemplated by the Underwriting Agreement or the Indenture; and (iv) will not result in any violation of any judgment, regulation, order or decree known to such counsel of any court, regulatory body, administrative agency, governmental body, arbitrator or other authority having jurisdiction over the Company or any of its subsidiaries or any of its or their properties.

(xvii) Neither the Company nor any Guarantor is or immediately after giving effect to the sale of the Securities in accordance with the Underwriting Agreement and the application

of the proceeds as described in the Preliminary Prospectus and the Prospectus under the caption “Use of Proceeds,” will be an “investment company” or a company “controlled” by an “investment company” within the meaning of the Investment Company Act of 1940, as amended.

(xviii) Except as disclosed in the Preliminary Prospectus and the Prospectus, to the best knowledge of such counsel, there are no persons with registration or other similar rights to have any equity or debt securities registered for sale under the Registration Statement or included in the offering contemplated by the Underwriting Agreement, except for such rights as have been duly waived.

(xix) To the best knowledge of such counsel, neither the Company nor any Guarantor (A) is in violation of (i) its charter, by-laws, operating agreement or limited liability company agreement, as the case may be, or (ii) any statute, law, rule, judgment, regulation, order or decree applicable to the Company or any of the Guarantors of any court, regulatory body, administrative agency, governmental body, arbitrator or other authority having jurisdiction over the Company or any of the Guarantors or any of its or their properties which, in the experience of such counsel would be applicable to the Company or any of the Guarantors in connection with transactions such as those contemplated by the Underwriting Agreement or the Indenture, or (B) is in Default in the performance or observance of any obligation, agreement, covenant or condition contained in any material Existing Instrument, except with respect to this clause (B) only, for such Defaults as would not, individually or in the aggregate, result in a Material Adverse Change.

To the best knowledge of such counsel, there are no contracts or other documents which are required to be described in the Prospectus or filed as exhibits to the Registration Statement by the Securities Act which have not been described or filed as exhibits to the Registration Statement or incorporated therein by reference as permitted by the Securities Act.

In addition, such counsel shall state that they have participated in conferences with officers and other representatives of the Company, representatives of the independent registered public or certified public accountants for the Company and representatives of the Underwriters at which the contents of the Registration Statement, the Disclosure Package, the Prospectus, and any supplements or amendments thereto, and related matters were discussed and, although such counsel is not passing upon and does not assume any responsibility for the accuracy, completeness or fairness of the statements contained in the Registration Statement, the Prospectus or any documents that constitute part of the Disclosure Package including the documents incorporated by reference therein (other than as specified above), and any supplements or amendments thereto, on the basis of the foregoing, nothing has come to their attention which would lead them to believe that (i) either the Registration Statement or any amendments thereto, at the time the Registration Statement or such amendments became effective, contained an untrue statement of a material fact or omitted to state a material fact required to be stated therein or necessary in order to make the statements therein not misleading; (ii) the Prospectus, as of its date or at the Closing Date contained an untrue statement of a material fact or omitted to state a material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading; or (iii) the Disclosure Package, as of the Applicable Time, contained any untrue statement of a material fact or omitted to state any material fact necessary in order to make the statements therein, in the light of circumstances under which they were made, not misleading

(it being understood that such counsel need express no belief as to the content of the financial statements or schedules or other financial data derived therefrom, estimated oil and natural gas reserve estimations and related calculations, assessments of or reports on the effectiveness of internal control over financial reporting included or incorporated by reference in the Registration Statement, the Prospectus, the Disclosure Package, the Trustee’s Statement of Eligibility on Form T-1 or any amendments or supplements thereto).

In rendering such opinion, such counsel may rely (A) as to matters involving the application of laws of any jurisdiction other than the General Corporation Law of the State of Delaware, the New York Corporation Law or the federal law of the United States, to the extent they deem proper and specified in such opinion, upon the opinion (which shall be dated the Closing Date shall be satisfactory in form and substance to the Underwriters, shall expressly state that the Underwriters may rely on such opinion as if it were addressed to them and shall be furnished to the Representatives) of other counsel of good standing whom they believe to be reliable and who are satisfactory to counsel for the Underwriters; provided, however, that such counsel shall further state that they believe that they and the Underwriters are justified in relying upon such opinion of other counsel, and (B) as to matters of fact, to the extent they deem proper, on certificates of responsible officers of the Company and public officials.

Opinion of General Counsel for the Company and the Guarantors to be delivered pursuant to Section 6(f) of the Underwriting Agreement.

(i) The Company and each Guarantor possess such valid and current licenses, certificates, authorizations or permits issued by the appropriate state, federal or foreign regulatory agencies or bodies necessary to conduct their respective businesses, and neither the Company nor any Guarantor has received any notice of proceedings relating to the revocation or modification of, or non-compliance with, any such license, certificate, authorization or permit which, singly or in the aggregate, if the subject of an unfavorable decision, ruling or finding, would result in a Material Adverse Change.


Delaware	1-9260	73-1283193
(State or other jurisdiction of incorporation)	(Commission File Number)	(I.R.S. Employer Identification No.)

7130 South Lewis, Suite 1000, Tulsa, Oklahoma		74136
(Address of principal executive offices)		(Zip Code)


Exhibit 1		Underwriting Agreement dated May 11, 2011, between the Company and Merrill Lynch, Pierce, Fenner & Smith Incorporated, acting for itself and as representative of the several underwriters.

Exhibit 99		Press Release, dated May 11, 2011.


Exhibit 1		Underwriting Agreement dated May 11, 2011, between the Company and Merrill Lynch, Pierce, Fenner & Smith Incorporated, acting for itself and as representative of the several underwriters.

Exhibit 99		Press Release, dated May 11, 2011.


MERRILL LYNCH, PIERCE, FENNER & SMITH
INCORPORATED

Acting as Representative of the several Underwriters named in the attached Schedule A.

By:		Merrill Lynch, Pierce, Fenner & Smith Incorporated

By:		/s/ J. Lex Maultshy
		J. Lex Maultshy
		Managing Director


Underwriters	Principal Amount of Securities To Be Purchased

Merrill Lynch, Pierce, Fenner & Smith Incorporated	$	128,125,000
BMO Capital Markets Corp.		49,859,000
Banco Bilbao Vizcaya Argentaria, S.A.		17,727,000
BNP Paribas Securities Corp.		13,849,000
Comerica Securities, Inc.		13,849,000
Credit Agricole Securities (USA) Inc.		13,849,000
Bosc, Inc.		8,310,000
BB&T Capital Markets, a division of Scott & Stringfellow, LLC.		4,432,000
Total	$	250,000,000


Issuer:		Unit Corporation (the “Company”)

Guarantees:		Each of the Company’s existing and future domestic restricted subsidiaries will jointly and severally, fully and unconditionally, guarantee, on a senior subordinated basis, the Company’s obligations under the Notes and all obligations under the Indenture.

Principal Amount:		$250,000,000

Net Proceeds:		$244,000,000

Use of Proceeds		To repay outstanding borrowings under the Company’s unsecured credit facility, and for general working capital purposes

Title of Securities:		6⁵/8% Senior Subordinated Notes due 2021 (the “Notes”)

Final Maturity Date:		May 15, 2021

Benchmark:		3.625% UST due 2/15/21

Spread to Benchmark:		+342 bps

Price to Public:		100%, plus accrued interest, if any, from May 18, 2011

Coupon:		6.625%

Yield to Maturity:		6.625%

Interest Payment Dates:		Semi-annually in arrears on each May 15 and November 15, beginning on November 15, 2011


Record Dates:		Each May 1 and November 1 immediately preceding the related interest payment dates

Optional Redemption:		On and after May 15, 2016, the Company may redeem all or, from time to time, a part of the Notes, at the following redemption prices (expressed as a percentage of principal amount) plus accrued and unpaid interest on the Notes, if any, to the redemption date, if redeemed during the twelve-month period beginning on May 15 of the years indicated below:



Year		Percentage
2016		103.313%
2017		102.208%
2018		101.104%
2019 and thereafter		100.000%



		In addition, at any time before May 15, 2016, the Company may redeem the Notes, in whole or in part, at a redemption price equal to 100% of the principal amount thereof plus the Applicable Premium plus accrued and unpaid interest, if any, to the redemption date.

Optional Redemption with Equity Proceeds:		Up to 35% at 106.625% prior to May 15, 2014

Change of Control:		Put at 101% of the principal amount of the Notes plus accrued and unpaid interest

Joint Book-Running Managers:		Merrill Lynch, Pierce, Fenner & Smith Incorporated BMO Capital Markets Corp.

Co-Managers:		Banco Bilbao Vizcaya Argentaria, S.A. Credit Agricole Securities (USA) Inc. BNP Paribas Securities Corp. Comerica Securities, Inc. Bosc, Inc. BB&T Capital Markets, a division of Scott & Stringfellow, LLC.

Trade Date:		May 11, 2011

Settlement Date:		May 18, 2011 (T+5 business days)

Denominations:		$2,000 and integral multiples of $1,000 in excess of $2,000

CUSIP/ISIN:		909218 AB5/US909218AB56

Distribution:		SEC Registered

Changes to the Preliminary Prospectus Supplement:		The following changes will be made to the Preliminary Prospectus Supplement:


news		UNIT CORPORATION