35,000,000 Shares HALCÓN RESOURCES CORPORATION Common Stock UNDERWRITING AGREEMENT

Very truly yours,

EX-1.1 2 d410874dex11.htm UNDERWRITING AGREEMENT Underwriting Agreement

Exhibit 1.1

Execution Version

35,000,000 Shares

HALCÓN RESOURCES CORPORATION

Common Stock

UNDERWRITING AGREEMENT

September 12, 2012

BARCLAYS CAPITAL INC.

GOLDMAN, SACHS & CO.

J.P. MORGAN SECURITIES LLC

As Representatives of the several

Underwriters named in Schedule 1 attached hereto,

c/o Barclays Capital Inc.

745 Seventh Avenue

New York, New York 10019

Ladies and Gentlemen:

EnCap Energy Capital Fund VIII, L.P. (the “Selling Stockholder”) proposes to sell 35,000,000 shares (the “Firm Stock”) of common stock of Halcón Resources Corporation, a Delaware corporation (the “Company”), par value $0.0001 per share (the “Common Stock”) to the underwriters named in Schedule 1 (the “Underwriters”) attached to this agreement (this “Agreement”). In addition, the Selling Stockholder proposes to grant to the Underwriters an option to purchase up to 5,250,000 additional shares of the Common Stock on the terms set forth in Section 3 (the “Option Stock”). The Firm Stock and the Option Stock, if purchased, are hereinafter collectively called the “Stock.” This Agreement is to confirm the agreement concerning the purchase of the Stock from the Selling Stockholder by the Underwriters.

As of the date hereof, the Selling Stockholder owns directly a 60% ownership interest in HALRES LLC, a Delaware limited liability company, which owns 73,333,334 shares of Common Stock in the Company. Immediately prior to the Delivery Date (as hereinafter defined), HALRES LLC will distribute 35,000,000 shares of Common Stock to the Selling Stockholder to be sold by the Selling Stockholder to the Underwriters under this Agreement. If the Underwriters exercise the option to purchase the Option Stock as set forth in Section 3 of this Agreement, HALRES LLC will distribute an additional 5,250,000 shares of Common Stock to the Selling Stockholder. Each such distribution by HALRES LLC to the Selling Stockholder herein as a “HALRES Distribution” and are referred to together as the “HALRES Distributions”).

1. Representations, Warranties and Agreements of the Company. The Company represents, warrants and agrees that:

(a) A registration statement on Form S-3 relating to the Stock (i) has been prepared by the Company in conformity with the requirements of the Securities Act of 1933, as amended (the “Securities Act”), and the rules and regulations (the “Rules and Regulations”) of the Securities and Exchange Commission (the “Commission”) thereunder; (ii) has been filed with the Commission under the Securities Act; and (iii) is effective under the Securities Act. Copies of such registration statement and any amendment thereto have been delivered by the Company to you as the representatives (the “Representatives”) of the Underwriters. As used in this Agreement:

(i) “Applicable Time” means 5:00 p.m. (New York City time) September 12, 2012;

(ii) “Effective Date” means any date as of which any part of such registration statement relating to the Stock became, or is deemed to have become, effective under the Securities Act in accordance with the Rules and Regulations;

(iii) “Issuer Free Writing Prospectus” means each “free writing prospectus” (as defined in Rule 405 of the Rules and Regulations) prepared by or on behalf of the Company or used or referred to by the Company in connection with the offering of the Stock;

(iv) “Preliminary Prospectus” means any preliminary prospectus relating to the Stock included in such registration statement or filed with the Commission pursuant to Rule 424(b) of the Rules and Regulations, including any preliminary prospectus supplement thereto relating to the Stock;

(v) “Pricing Disclosure Package” means, as of the Applicable Time, the most recent Preliminary Prospectus, together with the information included in Schedule 3 hereto and each Issuer Free Writing Prospectus filed or used by the Company on or before the Applicable Time, other than a road show that is an Issuer Free Writing Prospectus under Rule 433 of the Rules and Regulations;

(vi) “Prospectus” means the final prospectus relating to the Stock, including any prospectus supplement thereto relating to the Stock, as filed with the Commission pursuant to Rule 424(b) of the Rules and Regulations; and

(vii) “Registration Statement” means, collectively, the various parts of such registration statement, each as amended as of the Effective Date for such part, including any Preliminary Prospectus or the Prospectus and all exhibits to such registration statement.

Any reference to any Preliminary Prospectus or the Prospectus shall be deemed to refer to and include any documents incorporated by reference therein pursuant to Form S-3 under the Securities Act as of the date of such Preliminary Prospectus or the Prospectus, as the case may be. Any reference to the “most recent Preliminary Prospectus” shall be deemed to refer to the latest Preliminary Prospectus included in the Registration Statement or filed pursuant to Rule 424(b) prior to or on the date hereof (including, for purposes hereof, any documents incorporated by reference therein prior to or on the date

hereof). Any reference to any amendment or supplement to any Preliminary Prospectus or the Prospectus shall be deemed to refer to and include any document filed under the Securities Exchange Act of 1934, as amended (the “Exchange Act”), after the date of such Preliminary Prospectus or the Prospectus, as the case may be, and incorporated by reference in such Preliminary Prospectus or the Prospectus, as the case may be; and any reference to any amendment to the Registration Statement shall be deemed to include any annual report of the Company on Form 10-K filed with the Commission pursuant to Section 13(a) or 15(d) of the Exchange Act after the Effective Date that is incorporated by reference in the Registration Statement. The Commission has not issued any order preventing or suspending the use of any Preliminary Prospectus or the Prospectus or suspending the effectiveness of the Registration Statement, and no proceeding or examination for such purpose has been instituted or threatened by the Commission. The Commission has not notified the Company of any objection to the use of the form of the Registration Statement.

(b) The Company has been since the time of initial filing of the Registration Statement and continues to be a “well-known seasoned issuer” (as defined in Rule 405) eligible to use Form S-3 for the offering of the Stock, including not having been an “ineligible issuer” (as defined in Rule 405) at any such time or date. The Registration Statement is an “automatic shelf registration statement” (as defined in Rule 405) and was filed not earlier than the date that is three years prior to the applicable Delivery Date (as hereinafter defined).

(c) The Registration Statement conformed and will conform in all material respects on the Effective Date and on the applicable Delivery Date, and any amendment to the Registration Statement filed after the date hereof will conform in all material respects when filed, to the requirements of the Securities Act and the Rules and Regulations. The most recent Preliminary Prospectus conformed, and the Prospectus will conform, in all material respects when filed with the Commission pursuant to Rule 424(b) and on the applicable Delivery Date to the requirements of the Securities Act and the Rules and Regulations. The documents incorporated by reference in any Preliminary Prospectus or the Prospectus conformed, and any further documents so incorporated will conform, when filed with the Commission, in all material respects to the requirements of the Exchange Act or the Securities Act, as applicable, and the rules and regulations of the Commission thereunder.

(d) The Registration Statement did not, as of the Effective Date, contain an untrue statement of a material fact or omit to state a material fact required to be stated therein or necessary to make the statements therein not misleading; provided that no representation or warranty is made as to information contained in or omitted from the Registration Statement in reliance upon and in conformity with written information furnished to the Company through the Representatives by or on behalf of any Underwriter specifically for inclusion therein, which information is specified in Section 10(f).

(e) The Prospectus will not, as of its date and on the applicable Delivery Date, contain an untrue statement of a material fact or omit to state a material fact required to

be stated therein or necessary to make the statements therein, in the light of the circumstances under which they were made, not misleading; provided that no representation or warranty is made as to information contained in or omitted from the Prospectus in reliance upon and in conformity with written information furnished to the Company through the Representatives by or on behalf of any Underwriter specifically for inclusion therein, which information is specified in Section 10(f).

(f) The documents incorporated by reference in any Preliminary Prospectus or the Prospectus did not, and any further documents filed and incorporated by reference therein will not, when filed with the Commission, contain an untrue statement of a material fact or omit to state a material fact required to be stated therein or necessary to make the statements therein, in the light of the circumstances under which they were made, not misleading.

(g) The Pricing Disclosure Package did not, as of the Applicable Time, contain an untrue statement of a material fact or omit to state a material fact necessary to make the statements therein, in the light of the circumstances under which they were made, not misleading; provided that no representation or warranty is made as to information contained in or omitted from the Pricing Disclosure Package in reliance upon and in conformity with written information furnished to the Company through the Representatives by or on behalf of any Underwriter specifically for inclusion therein, which information is specified in Section 10(f).

(h) Each Issuer Free Writing Prospectus (including, without limitation, any road show that is a free writing prospectus under Rule 433), when considered together with the Pricing Disclosure Package as of the Applicable Time, did not contain an untrue statement of a material fact or omit to state a material fact required to be stated therein or necessary to make the statements therein, in the light of the circumstances under which they were made, not misleading; provided that no representation or warranty is made as to information contained in or omitted from the Pricing Disclosure Package in reliance upon and in conformity with written information furnished to the Company through the Representatives by or on behalf of any Underwriter specifically for inclusion therein, which information is specified in Section 10(f).

(i) Each Issuer Free Writing Prospectus conformed or will conform in all material respects to the requirements of the Securities Act and the Rules and Regulations on the date of first use, and the Company has complied with any filing requirements applicable to such Issuer Free Writing Prospectus pursuant to the Rules and Regulations. The Company has not made any offer relating to the Stock that would constitute an Issuer Free Writing Prospectus without the prior written consent of the Representatives. The Company has retained in accordance with the Rules and Regulations all Issuer Free Writing Prospectuses that were not required to be filed pursuant to the Rules and Regulations.

(j) The Company has been duly incorporated, is validly existing and is in good standing under the laws of State of Delaware, with corporate power and authority to own, lease and operate its properties and conduct its business as described in the Pricing

Disclosure Package and the Prospectus; the Company is duly qualified as a foreign corporation to transact business and is in good standing in each other jurisdiction in which such qualification is required, whether by reason of the ownership or leasing of property or the conduct of business, except where the failure to qualify or to be in good standing would not have a material adverse effect on the business, properties, prospects, financial condition, stockholders’ equity or results of operations of the Company and its subsidiaries taken as a whole (a “Material Adverse Effect”); each subsidiary of the Company other than those subsidiaries which would not, individually or in the aggregate, constitute a “significant subsidiary” as defined in Item 1-02(w) of Regulation S-X (each such “significant subsidiary,” a “Subsidiary”) is a corporation, partnership, limited liability company or business trust duly incorporated or organized, validly existing and in good standing under the laws of the jurisdiction of its incorporation or organization, except where the failure to qualify or to be in good standing would not have a Material Adverse Effect, with the requisite entity power and authority to own, lease and operate its properties. The Company does not own or control, directly or indirectly, any corporation, association or other corporate entity that, individually or in the aggregate would constitute a Subsidiary, other than the subsidiaries listed on Schedule II hereof. On a consolidated basis, the Company and its subsidiaries conduct their business as described in the Preliminary Prospectus and the Pricing Disclosure Package and each Subsidiary is duly qualified as a foreign corporation, partnership, limited liability company, business trust or other organization 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 where the failure to qualify or to be in good standing would not result in a Material Adverse Effect.

(k) The Company has the authorized equity capitalization as set forth in the Preliminary Prospectus and the Pricing Disclosure Package, and all of the issued and outstanding shares of capital stock of the Company have been duly authorized and validly issued and are fully paid and non-assessable. Except as otherwise disclosed in the Preliminary Prospectus and the Pricing Disclosure Package, all of the issued and outstanding capital stock or other ownership interests of each subsidiary of the Company (i) have been duly authorized and validly issued, (ii) are fully paid and non-assessable and (iii) are owned by the Company directly or through subsidiaries, free and clear of any security interest, mortgage, pledge, lien, encumbrance, claim or equity except as described in the Preliminary Prospectus and the Pricing Disclosure Package and except for such security interests, mortgages, pledges, liens, encumbrances, claims or equities that would not, individually or in the aggregate, reasonably be expected to have a Material Adverse Effect.

(l) The Company has all requisite corporate power and authority to execute, deliver and perform its obligations under this Agreement. This Agreement has been duly and validly authorized, executed and delivered by the Company.

(m) The execution, delivery and performance of this Agreement by the Company, the consummation of the transactions contemplated hereby will not (i) conflict with or result in a breach or violation of any of the terms or provisions of, impose any lien, charge or encumbrance upon any property or assets of the Company and its

subsidiaries, or constitute a default under, any indenture, mortgage, deed of trust, loan agreement, license or other agreement or instrument to which the Company or any of its subsidiaries is a party or by which the Company or any of its subsidiaries is bound or to which any of the property or assets of the Company or any of its subsidiaries is subject; (ii) result in any violation of the provisions of the charter or by-laws (or similar organizational documents) of the Company or any of its subsidiaries; or (iii) result in any violation of any statute or any order, rule or regulation of any court or governmental agency or body having jurisdiction over the Company or any of its subsidiaries or any of their properties or assets, except, with respect to clauses (i) and (iii), conflicts or violations that would not reasonably be expected to have a Material Adverse Effect or could, in the aggregate, reasonably be expected to have a material adverse effect on the performance of this Agreement or the consummation of the transactions contemplated hereby.

(n) No consent, approval, authorization or order of, or filing or registration with, any court or governmental agency or body having jurisdiction over the Company or any of its subsidiaries or any of their properties or assets is required for the execution, delivery and performance of this Agreement by the Company, except for the registration of the Stock under the Securities Act and such consents, approvals, authorizations, registrations or qualifications as may be required under the Exchange Act and applicable state securities laws in connection with the purchase and sale of the Stock by the Underwriters.

(o) Except as described in the most recent Preliminary Prospectus and the Pricing Disclosure Package, there are no contracts, agreements or understandings between the Company and any person granting such person the right to require the Company to include securities in the securities registered pursuant to the Registration Statement.

(p) The Company has not sold or issued any securities that would be integrated with the offering of the Stock contemplated by this Agreement pursuant to the Securities Act, the Rules and Regulations or the interpretations thereof by the Commission.

(q) Except as described in the most recent Preliminary Prospectus and the Pricing Disclosure Package, neither the Company nor any of its subsidiaries has sustained, since the date of the latest audited financial statements included or incorporated by reference in the most recent Preliminary Prospectus, any loss or interference with its business from fire, explosion, flood or other calamity, whether or not covered by insurance, or from any labor dispute or court or governmental action, order or decree, and since such date, there has not been any change in the capital stock or long-term debt of the Company or any of its subsidiaries or any adverse change, or any development involving a prospective adverse change, in or affecting the business, properties, prospects, financial condition, stockholders’ equity or results of operations of the Company and its subsidiaries taken as a whole, in each case except as could not, in the aggregate, reasonably be expected to have a Material Adverse Effect.

(r) Since the date as of which information is given in the most recent Preliminary Prospectus and the Pricing Disclosure Package and except as described in the most recent Preliminary Prospectus and the Pricing Disclosure Package, the Company has not (i) incurred any material liability or obligation, direct or contingent, other than liabilities and obligations that were incurred in the ordinary course of business, (ii) entered into any material transaction not in the ordinary course of business or (iii) declared or paid any dividend on its capital stock.

(s) The historical financial statements (including the related notes and supporting schedules) of each of the Company, GeoResources, and the East Texas Assets included or incorporated by reference in the most recent Preliminary Prospectus and the Pricing Disclosure Package comply as to form in all material respects with the requirements of Regulation S-X under the Securities Act and present fairly the financial condition, results of operations and cash flows of the entities purported to be shown thereby at the dates and for the periods indicated and have been prepared in conformity with accounting principles generally accepted in the United States applied on a consistent basis throughout the periods involved.

(t) The pro forma financial statements included or incorporated by reference in the most recent Preliminary Prospectus and the Pricing Disclosure Package include assumptions that provide a reasonable basis for presenting the significant effects directly attributable to the transactions and events described therein, the related pro forma adjustments give appropriate effect to those assumptions, and the pro forma adjustments reflect the proper application of those adjustments to the historical financial statement amounts in the pro forma financial statements included in the most recent Preliminary Prospectus and the Pricing Disclosure Package. The pro forma financial statements included in the most recent Preliminary Prospectus and the Pricing Disclosure Package have been prepared in accordance with the Commission’s rules and guidance with respect to pro forma financial information. The pro forma financial statements included in the Preliminary Prospectus and the Pricing Disclosure Package have been prepared on the basis consistent with such historical financial statements, except for the pro forma adjustments specified therein, and include all material adjustments to the historical financial data required by Rule 11-02 of Regulation S-X to reflect the GeoResources Merger and the acquisition of the East Texas Assets and to give effect to the issuance of the Company’s 9.75% Senior Notes due 2020, and give effect to assumptions made on a reasonable basis and in good faith and present fairly in all material respects the historical and proposed transactions reflected therein. The other financial information and data included and incorporated by reference in the most recent Preliminary Prospectus and the Pricing Disclosure Package, historical and pro forma, are, in all material respects, accurately presented and prepared on a basis consistent with such financial statements and the books and records of the Company.

(u) Deloitte & Touche LLP, who have delivered the initial letter referred to in Section 9(h) hereof, are independent registered public accountants as required by the Securities Act and the rules and regulations thereunder and the rules and regulations of the Public Company Accounting Oversight Board (the “PCAOB”) during the periods covered by the financial statements on which they reported contained in and incorporated by reference in the most recent Preliminary Prospectus and the Pricing Disclosure Package.

(v) UHY LLP, who have certified certain financial statements of the Company and the East Texas Assets, whose reports appear in the most recent Preliminary Prospectus and the Pricing Disclosure Package or are incorporated by reference therein and who have delivered the initial letter referred to in Section 9(h) hereof, are independent registered public accountants as required by the Securities Act and the rules and regulations thereunder and the rules and regulations of the PCAOB during the periods covered by the financial statements on which they reported contained in and incorporated by reference in the most recent Preliminary Prospectus and the Pricing Disclosure Package.

(w) Grant Thornton LLP, who have certified certain financial statements of GeoResources, whose reports appear in the most recent Preliminary Prospectus and the Pricing Disclosure Package or are incorporated by reference therein and who have delivered the initial letter referred to in Section 9(h) hereof, are independent registered public accountants of GeoResources as required by the Securities Act and the rules and regulations thereunder and the rules and regulations of the PCAOB during the periods covered by the financial statements on which they reported contained in and incorporated by reference in the most recent Preliminary Prospectus and the Pricing Disclosure Package.

(x) Forrest A. Garb & Associates (the “Company Reservoir Engineer”), whose report dated February 7, 2012, is summarized or excerpted in reports incorporated by reference, or included, in the most recent Preliminary Prospectus and the Pricing Disclosure Package, was, as of the date of such report, and is, as of the date hereof, an independent petroleum engineer with respect to the Company. The written engineering report prepared by the Company Reservoir Engineer dated February 7, 2012 setting forth the proved reserves attributed to the oil and gas properties of the Company and its subsidiaries accurately reflects in all material respects the interests of the Company its subsidiaries in the properties therein as of December 31, 2011 and was prepared in accordance with the SEC’s rules and regulations relating to the reporting of oil and natural gas reserves; the information furnished by the Company to the Company Reservoir Engineer for purposes of preparing its report, including, without limitation, production, costs of operation and development, current prices for production, agreements relating to current and future operations and sales of production, was true, correct and complete in all material respects on the date supplied and was prepared in accordance with customary industry practices, as indicated in the letter of the Company Reservoir Engineer dated February 7, 2012. The estimates of proved reserves and related information relating to the East Texas Assets prepared by the Company’s internal reserve engineering staff as of December 31, 2011 and April 1, 2012 accurately reflect in all material respects the interests that the Company acquired therein and were prepared in a manner consistent with the rules and regulations of the SEC relating to the reporting of oil and gas reserves; the information used by the Company’s internal reserve engineers for purposes of preparing such estimates of proved reserves, including, without limitation, production, costs of operation and development, current prices for production, agreements relating to current and future operations and sales of production, was true, correct and complete in all material respects as of the date of such reserves.

(y) Cawley, Gillespie & Associates, Inc. (the “GeoResources Reservoir Engineer”), whose report dated February 27, 2012, is summarized or excerpted in reports incorporated by reference, or included, in the most recent Preliminary Prospectus and the Pricing Disclosure Package, was, as of the date of such report, and is, as of the date hereof, an independent petroleum engineer with respect to GeoResources. The written engineering report prepared by the GeoResources Reservoir Engineer dated February 27, 2012 setting forth the proved reserves attributed to the oil and gas properties of GeoResources and its subsidiaries accurately reflects in all material respects the interests of GeoResources and its subsidiaries in the properties therein as of December 31, 2011 and was prepared in accordance with the SEC’s rules and regulations relating to the reporting of oil and natural gas reserves; the information furnished by GeoResources to the GeoResources Reservoir Engineer for purposes of preparing its report, including, without limitation, production, costs of operation and development, current prices for production, agreements relating to current and future operations and sales of production, was true, correct and complete in all material respects on the date supplied and was prepared in accordance with customary industry practices, as indicated in the letter of the GeoResources Reservoir Engineer dated February 27, 2012. The estimates of proved reserves and related information relating to the Brookeland fields prepared by GeoResources’ internal reserve engineering staff as of December 31, 2011 accurately reflect in all material respects the interests that GeoResources has therein and were prepared in a manner consistent with the rules and regulations of the SEC relating to the reporting of oil and gas reserves; the information used by GeoResources’ internal reserve engineers for purposes of preparing such estimates of proved reserves, including, without limitation, production, costs of operation and development, current prices for production, agreements relating to current and future operations and sales of production, was true, correct and complete in all material respects as of the date of such reserves.

(z) The statistical and market-related data included in the most recent Preliminary Prospectus and the consolidated financial statements of the Company and its subsidiaries and of GeoResources and its subsidiaries and the financial statements of the East Texas Assets included or incorporated by reference in the most recent Preliminary Prospectus are based on or derived from sources that the Company believes to be reliable and accurate in all material respects.

(aa) Neither the Company nor any subsidiary is an “investment company” within the meaning of such term under the Investment Company Act of 1940, as amended (the “Investment Company Act”).

(bb) Except as described in the most recent Preliminary Prospectus and the Pricing Disclosure Package, there are no legal or governmental proceedings pending 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 that could, in the aggregate, reasonably be expected to have a Material Adverse Effect or could, in the aggregate, reasonably be expected to have a material adverse effect on the performance of this

Agreement or the consummation of the transactions contemplated hereby; and to the Company’s knowledge, no such proceedings are threatened or contemplated by governmental authorities or others.

(cc) There are no contracts or other documents that would be required to be described in a registration statement filed under the Securities Act or filed as exhibits to a registration statement of the Company pursuant to Item 601(10) of Regulation S-K that have not been described in the most recent Preliminary Prospectus and the Pricing Disclosure Package. The statements made in the most recent Preliminary Prospectus and the Pricing Disclosure Package, insofar as they purport to constitute summaries of the terms of the contracts and other documents that are so described, constitute accurate summaries of the terms of such contracts and documents in all material respects. Neither the Company nor any of its subsidiaries has knowledge that any other party to any such contract or other document has any intention not to render full performance as contemplated by the terms thereof.

(dd) The statements made in the most recent Preliminary Prospectus and the Pricing Disclosure Package under the captions “Business” (as incorporated by reference from the Company’s Exchange Act Reports), “Certain U.S. Federal Income Tax Considerations to Non-U.S. Holders” and “Certain ERISA Considerations,” insofar as they purport to constitute summaries of the terms of statutes, rules or regulations, legal or governmental proceedings or contracts and other documents, constitute accurate summaries of the terms of such statutes, rules and regulations, legal and governmental proceedings and contracts and other documents in all material respects.

(ee) No relationship, direct or indirect, that would be required to be described in a registration statement of the company pursuant to Item 404 of Regulation S-K exists between or among the Company, on the one hand, and the directors, officers, stockholders, customers or suppliers of the Company, on the other hand which is not so described in the Preliminary Prospectus and the Pricing Disclosure Package.

(ff) No labor disturbance by the employees of the Company or its subsidiaries exists or, to the knowledge of the Company, is imminent that could reasonably be expected to have a Material Adverse Effect.

(gg)(i) Each “employee benefit plan” (within the meaning of Section 3(3) of the Employee Retirement Security Act of 1974, as amended (“ERISA”)) for which the Company or any member of its “Controlled Group” (defined as any organization which is a member of a controlled group of corporations within the meaning of Section 414 of the Internal Revenue Code of 1986, as amended (the “Code”)) would have any liability (each a “Plan”) has been maintained in compliance with its terms and with the requirements of all applicable statutes, rules and regulations including ERISA and the Code; (ii) with respect to each Plan subject to Title IV of ERISA (a) no “reportable event” (within the meaning of Section 4043(c) of ERISA) has occurred or is reasonably expected to occur, (b) no “accumulated funding deficiency” (within the meaning of Section 302 of ERISA or Section 412 of the Code), whether or not waived, has occurred or is reasonably expected to occur, (c) the fair market value of the assets under each Plan exceeds the

present value of all benefits accrued under such Plan (determined based on those assumptions used to fund such Plan) and (d) neither the Company or any member of its Controlled Group has incurred, or reasonably expects to incur, any liability under Title IV of ERISA (other than contributions to the Plan or premiums to the PBGC in the ordinary course and without default) in respect of a Plan (including a “multiemployer plan”, within the meaning of Section 4001(c)(3) of ERISA); and (iii) each Plan that is intended to be qualified under Section 401(a) of the Code is so qualified and nothing has occurred, whether by action or by failure to act, which would cause the loss of such qualification.

(hh) The Company and each of its subsidiaries have filed all federal, state, local and foreign income and franchise tax returns required to be filed through the date hereof, subject to permitted extensions, and have paid all taxes due thereon, and no tax deficiency has been determined adversely to the Company or any of its subsidiaries, nor does the Company have any knowledge of any tax deficiencies that could, in the aggregate, reasonably be expected to have a Material Adverse Effect.

(ii) Neither the Company nor any of its subsidiaries (i) is in violation of its charter or by-laws (or similar organizational documents), (ii) is in default, and no event has occurred that, with notice or lapse of time or both, would constitute such a default, in the due performance or observance of any term, covenant or condition contained in any indenture, mortgage, deed of trust, loan agreement, license or other agreement or instrument to which it is a party or by which it is bound or to which any of its properties or assets is subject or (iii) is in violation of any statute or any order, rule or regulation of any court or governmental agency or body having jurisdiction over it or its property or assets or has failed to obtain any license, permit, certificate, franchise or other governmental authorization or permit necessary to the ownership of its property or to the conduct of its business, except in the case of clauses (ii) and (iii), to the extent any such conflict, breach, violation or default could not, in the aggregate, reasonably be expected to have a Material Adverse Effect.

(jj) There is and has been no failure on the part of the Company and any of the Company’s directors or officers, in their capacities as such, to comply with the provisions of the Sarbanes-Oxley Act of 2002 and the rules and regulations promulgated in connection therewith.

(kk) The Company and each of its subsidiaries have such permits, licenses, patents, franchises, certificates of need and other approvals or authorizations of governmental or regulatory authorities (“Permits”) as are necessary under applicable law to own their properties and conduct their businesses in the manner described in the most recent Preliminary Prospectus and the Pricing Disclosure Package, except for any of the foregoing that could not, in the aggregate, reasonably be expected to have a Material Adverse Effect; each of the Company and its subsidiaries has fulfilled and performed all of its obligations with respect to the Permits, and no event has occurred that allows, or after notice or lapse of time would allow, revocation or termination thereof or results in any other impairment of the rights of the holder or any such Permits, except for any of the foregoing that could not reasonably be expected to have a Material Adverse Effect.

(ll) The Company and each of its subsidiaries own or possess adequate rights to use all material patents, patent applications, trademarks, service marks, trade names, trademark registrations, service mark registrations, copyrights, licenses, know-how, software, systems and technology (including trade secrets and other unpatented and/or unpatentable proprietary or confidential information, systems or procedures) necessary for the conduct of their respective businesses and have no reason to believe that the conduct of their respective businesses will conflict with, and have not received any notice of any claim of conflict with, any such rights of others.

(mm) The Company and each of its subsidiaries (i) are, and at all times prior hereto were, in compliance with all laws, regulations, ordinances, rules, orders, judgments, decrees, permits or other legal requirements of any governmental authority, including without limitation any international, national, state, provincial, regional, or local authority, relating to the protection of human health or safety, the environment, or natural resources, or to hazardous or toxic substances or wastes, pollutants or contaminants (“Environmental Laws”) applicable to such entity, which compliance includes, without limitation, obtaining, maintaining and complying with all permits and authorizations and approvals required by Environmental Laws to conduct their respective businesses, and (ii) have not received notice of any actual or alleged violation of Environmental Laws, or of any potential liability for or other obligation concerning the presence, disposal or release of hazardous or toxic substances or wastes, pollutants or contaminants, except in the case of clause (i) or (ii) where such non-compliance, violation, liability, or other obligation could not, in the aggregate, reasonably be expected to have a Material Adverse Effect. Except as described in the most recent Preliminary Prospectus and the Pricing Disclosure Package, (A) there are no proceedings that are pending, or known to be contemplated, against the Company or any of its subsidiaries under Environmental Laws in which a governmental authority is also a party, other than such proceedings regarding which it is reasonably believed no monetary sanctions of $100,000 or more will be imposed, (B) the Company and its subsidiaries are not aware of any issues regarding compliance with Environmental Laws, or liabilities or other obligations under Environmental Laws or concerning hazardous or toxic substances or wastes, pollutants or contaminants, that could reasonably be expected to have a Material Adverse Effect, and (C) none of the Company and its subsidiaries anticipates material capital expenditures other than in the ordinary course of business relating to Environmental Laws.

(nn) Neither the Company nor any of its subsidiaries, nor, to the knowledge of the Company, any director, officer, agent, employee or other person associated with or acting on behalf of the Company or any of its subsidiaries, has (i) used any corporate funds for any unlawful contribution, gift, entertainment or other unlawful expense relating to political activity; (ii) made any direct or indirect unlawful payment to any foreign or domestic government official or employee from corporate funds; (iii) violated or is in violation of any provision of the U.S. Foreign Corrupt Practices Act of 1977; or (iv) made any bribe, rebate, payoff, influence payment, kickback or other unlawful payment.

(oo) 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 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 knowledge of the Company, threatened, except, in each case, as would not reasonably be expected to have a Material Adverse Effect.

(pp) Neither the Company nor any of its subsidiaries nor, to the knowledge of the Company, 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.

(qq) The Company has not distributed and, prior to the later to occur of any Delivery Date and completion of the distribution of the Stock, will not distribute any offering material in connection with the offering and sale of the Stock other than any Preliminary Prospectus, the Prospectus, any Issuer Free Writing Prospectus to which the Representatives have consented in accordance with Section 1(i) or 6(a)(vii) and any Issuer Free Writing Prospectus set forth on Schedule 4 hereto.

(rr) The Company has not taken and will not take, directly or indirectly, any action designed to or that has constituted or that could reasonably be expected to cause or result in the stabilization or manipulation of the price of any security of the Company to facilitate the sale or resale of the shares of the Stock.

(ss) The Stock has been approved for listing on the New York Stock Exchange.

(tt) As of the date hereof, (i) all royalties, rentals, deposits and other amounts owed under the oil and gas leases constituting the oil and gas properties of the Company and its subsidiaries have been properly and timely paid (other than amounts held in suspense accounts pending routine payments or related to disputes about the proper identification of royalty owners), and no material amount of proceeds from the sale or production attributable to the oil and gas properties of the Company and the subsidiaries are currently being held in suspense by any purchaser thereof, except where such amounts due could not, individually or in the aggregate, have a Material Adverse Effect, and (ii) there are no claims under take-or-pay contracts pursuant to which natural gas purchasers have any make-up rights affecting the interests of the Company or the subsidiaries in their oil and gas properties, except where such claims could not, individually or in the aggregate, have a Material Adverse Effect.

(uu) The Company and its subsidiaries have defensible title to all of their interests in oil and gas properties (other than interests earned under farm-out, participation or similar agreements in which an assignment or transfer is pending) and all their interests in other real property and good title to all other properties owned by them, in each case, free and clear of all mortgages, pledges, liens, security interests, claims, restrictions or encumbrances of any kind except such as (i) are described in the most recent Preliminary Prospectus and the Pricing Disclosure Package, (ii) liens and encumbrances under operating agreements, unitization and pooling agreements, production sales contracts, farm-out agreements and other oil and gas exploration participation and production agreements, in each case that secure payment of amounts not yet due and payable for the performance of other unmatured obligations and are of a scope and nature customary in the oil and gas industry or arise in connection with drilling and production operations, or (iii) would not have a Material Adverse Effect; except as described in the most recent Preliminary Prospectus and the Pricing Disclosure Package, all of the leases and subleases of real property of the Company or any of its subsidiaries and under which the Company or any of its subsidiaries holds properties described in the most recent Preliminary Prospectus and the Pricing Disclosure Package, are in full force and effect.

(vv) The Company and each of its subsidiaries maintain a system of internal control over financial reporting (as such term is defined in Rule 13a-15(f) of the Exchange Act) that complies with the requirements of the Exchange Act and that has been designed by, or under the supervision of, the Company’s principal executive and principal financial officers, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles in the United States. The Company and each of its subsidiaries maintains internal accounting controls that are sufficient to provide reasonable assurance that (i) transactions are executed in accordance with management’s general or specific authorization, (ii) transactions are recorded as necessary to permit preparation of the Company’s financial statements in conformity with accounting principles generally accepted in the United States and to maintain accountability for its assets, (iii) access to the Company’s assets is permitted only in accordance with management’s general or specific authorization, and (iv) the recorded accountability for the Company’s assets is compared with existing assets at reasonable intervals and appropriate action is taken with respect to any differences.

(ww)(i) The Company and each of its subsidiaries have established and maintain disclosure controls and procedures (as such term is defined in Rule 13a-15 under the Exchange Act), (ii) such disclosure controls and procedures are designed to ensure that the information required to be disclosed by the Company in the reports they file or submit under the Exchange Act (assuming the Company was required to file or submit such reports under the Exchange Act) is accumulated and communicated to management of the Company and its subsidiaries, including their respective principal executive officers and principal financial officers, as appropriate, to allow timely

decisions regarding required disclosure to be made; and (iii) such disclosure controls and procedures are effective in all material respects to perform the functions for which they were established.

(xx) Since the date of the most recent balance sheet of the Company and its consolidated subsidiaries audited by UHY LLC and reviewed by the audit committee of the board of directors of the Company, (i) the Company has not been advised of by its auditors, nor has it identified (A) any significant deficiencies in the design or operation of internal controls, that would adversely affect the ability of the Company or any of its subsidiaries to record, process, summarize and report financial data, or any material weaknesses in internal controls, and (B) any fraud, whether or not material, that involves management or other employees who have a significant role in the internal controls of the Company and each of its subsidiaries; and (ii) there have been no changes in internal controls or in other factors that have materially affected or are reasonably likely to materially affect internal controls, including any corrective actions with regard to significant deficiencies and material weaknesses.

(yy) The section entitled “Management’s Discussion and Analysis of Financial Condition and Results of Operations–Critical Accounting Policies and Estimates” as incorporated by reference from the Company’s Exchange Act Reports in the Preliminary Prospectus and the Pricing Disclosure Package accurately and fully describes in all material respects (A) the accounting policies that the Company believed as of the date thereof were the most important in the portrayal of the Company’s financial condition and results of operations and that required management’s most difficult, subjective or complex judgments; (B) the judgments and uncertainties affecting the application of critical accounting policies; and (C) the likelihood that materially different amounts would be reported under different conditions or using different assumptions and an explanation thereof.

Any certificate signed by any officer of the Company and delivered to the Representatives or counsel for the Underwriters in connection with the offering of the Stock shall be deemed a representation and warranty by the Company, as to matters covered thereby, to each Underwriter.

2. Representations and Warranties of the Selling Stockholder. The Selling Stockholder hereby represents, warrants and agrees that:

(a) The Selling Stockholder has been duly formed and is validly existing and in good standing as a limited partnership under the laws of Texas.

(b) Neither the Selling Stockholder nor any person acting on behalf of the Selling Stockholder (other than, if applicable, the Company and the Underwriters) has used or referred to any Free Writing Prospectus relating to the Stock without the prior written consent of the Representatives, except as set forth on Schedule VI hereto.

(c) After giving effect to each HALRES Distribution, the Selling Stockholder will have valid title to the Stock or a valid “security entitlement” within the meaning of

Section 8-501 of the New York Uniform Commercial Code (the “UCC”) in respect thereof, free and clear of all Liens, and immediately prior to any Delivery Date on which the Selling Stockholder is selling Stock, the Selling Stockholder will have valid title to the Stock to be sold by the Selling Stockholder hereunder on such Delivery Date or a “security entitlement” within the meaning of Section 8-501 of the UCC in respect thereof, free and clear of all Liens.

(d) The Stock is subject to the interests of the Underwriters and the obligations of the Selling Stockholder hereunder shall not be terminated by any act of the Selling Stockholder, by operation of law or the occurrence of any other event.

(e) Upon (i) payment for the Stock to be sold by the Selling Stockholder pursuant to this Agreement, (ii) delivery of such Stock, as directed by the Underwriters, to Cede & Co. (“Cede”) or such other nominee as may be designated by the Depository Trust Company (“DTC”), (iii) registration of such Stock in the name of DTC, Cede, or such other nominee, and DTC or another person on behalf of DTC maintaining possession of certificates representing such Stock and (iv) DTC indicating by book entries on its books that security entitlements with respect to such Stock have been credited to the Underwriter’s securities account, the underwriters will acquire a security entitlement (within the meaning of Section 8-501 of the UCC) with respect to such Stock and no action based on an “adverse claim” (as defined in Section 8-102 of the UCC) may be asserted against the Underwriters (assuming the Underwriters are purchasing such Stock without notice of an adverse claim).

(f) The Selling Stockholder has all requisite limited partnership power and authority to execute, deliver and perform its obligations under this Agreement. This Agreement has been duly and validly authorized, executed and delivered by the Selling Stockholder.

(g) The offering and sale of the Stock to be sold by the Selling Stockholder, the execution, delivery and performance of this Agreement by the Selling Stockholder and the consummation by the Selling Stockholder of the transactions contemplated hereby do not and will not (i) conflict with or result in a breach or violation of any of the terms or provisions of, impose any lien, charge or encumbrance upon any property or assets of the Selling Stockholder, or constitute a default under, any indenture, mortgage, deed of trust, loan agreement, license, lease or other agreement or instrument to which the Selling Stockholder is a party or by which the Selling Stockholder is bound or to which any of the property or assets of the Selling Stockholder is subject; (ii) result in any violation of the provisions of the certificate of formation or limited partnership agreement of the Selling Stockholder; or (iii) result in any violation of any statute or any judgment, order, decree, rule or regulation of any court or governmental agency or body having jurisdiction over the Selling Stockholder or any of its properties or assets.

(h) No consent, approval, authorization or order of, or filing, registration or qualification with, any court or governmental agency or body having jurisdiction over the Selling Stockholder or any of its properties or assets is required for the offer and sale of the Stock, the execution, delivery and performance of this Agreement by the Selling

Stockholder, the consummation of the transactions contemplated hereby, except for the registration of the Stock under the Securities Act and such consents, approvals, authorizations, orders, filings, registrations or qualifications (i) as may be required under the Exchange Act, and applicable state securities laws in connection with the purchase and sale of the Stock by the Underwriters or (ii) as have been, or prior to the Initial Delivery Date or the Option Stock Delivery Date, as applicable, will be, obtained.

(i) In respect of any statements in or omissions from the Pricing Disclosure Package, the Prospectus or any Issuer Free Writing Prospectus or any amendment or supplement thereto used by the Company or any Underwriter, as the case may be, made in reliance upon and in conformity with information furnished to the Company by the Selling Stockholder specifically for use in connection with the preparation thereof, the Selling Stockholder hereby makes the same representations and warranties to each Underwriter as the Company makes to such Underwriter under paragraphs (1)(d) and (1)(e); it being understood and agreed that the foregoing applies only to (A) the legal name, address, and the number of shares of Stock owned by the Selling Stockholder, (B) any biographical information provided by the Selling Stockholder with respect to representatives of the Selling Stockholder that are members of the board of directors of the Company, and (C) the other information with respect to the Selling Stockholder (excluding percentages) which appear in the table (and corresponding footnotes) under the caption “Selling Stockholder” (with respect to the Selling Stockholder, the “Selling Stockholder Information”).

(j) The Selling Stockholder is not prompted to sell Stock by any information concerning the Company that is not set forth in the Registration Statement, the Pricing Disclosure Package and the Prospectus.

(k) The Selling Stockholder has not taken, directly or indirectly, any action that is designed to or that has constituted or that could reasonably be expected to cause or result in the stabilization or manipulation of the price of any security of the Company in connection with the offering of the Stock.

Any certificate signed by any officer of the Selling Stockholder and delivered to the Representatives or counsel for the Underwriters in connection with the offering of the Stock shall be deemed a representation and warranty by the Selling Stockholder, as to matters covered thereby, to each Underwriter.

3. Purchase of the Stock by the Underwriters. On the basis of the representations and warranties contained in, and subject to the terms and conditions of, this Agreement, the Selling Stockholder agrees to sell 35,000,000 shares of the Firm Stock to the several Underwriters, and each of the Underwriters, severally and not jointly, agrees to purchase the number of shares of the Firm Stock set forth opposite that Underwriter’s name in Schedule 1 hereto. The respective purchase obligations of the Underwriters with respect to the Firm Stock shall be rounded among the Underwriters to avoid fractional shares, as the Representatives may determine.

In addition, the Selling Stockholder grants to the Underwriters an option to purchase up to 5,250,000 additional shares of Option Stock. Such option is exercisable in the event that the Underwriters sell more shares of Common Stock than the number of Firm Stock in the offering and as set forth in Section 3 hereof. Each Underwriter agrees, severally and not jointly, to purchase the number of shares of Option Stock (subject to such adjustments to eliminate fractional shares as the Representatives may determine) that bears the same proportion to the total number of shares of Option Stock to be sold on such Delivery Date as the number of shares of Firm Stock set forth in Schedule 1 hereto opposite the name of such Underwriter bears to the total number of shares of Firm Stock.

The price of both the Firm Stock and any Option Stock purchased by the Underwriters shall be $6.72 per share.

The Selling Stockholder shall not be obligated to deliver any of the Firm Stock or Option Stock to be delivered on the applicable Delivery Date, except upon payment for all such Stock to be purchased on such Delivery Date as provided herein.

4. Offering of Stock by the Underwriters. Upon authorization by the Representatives of the release of the Firm Stock, the several Underwriters propose to offer the Firm Stock for sale upon the terms and conditions to be set forth in the Prospectus.

5. Delivery of and Payment for the Stock. Delivery of and payment for the Firm Stock by the Selling Stockholder shall be made at the office of Vinson & Elkins L.L.P. at 10:00 A.M., New York City time, on the third full business day following the date of this Agreement or at such other date or place as shall be determined by agreement between the Representatives and the Selling Stockholder. This date and time are sometimes referred to as the “Initial Delivery Date.” Delivery of the Firm Stock shall be made to the Representatives for the account of each Underwriter against payment by the several Underwriters through the Representatives and of the respective aggregate purchase prices of the Firm Stock being sold by the Selling Stockholder to or upon the order of the Selling Stockholder of the purchase price by wire transfer in immediately available funds to the accounts specified by the Selling Stockholder. Time shall be of the essence, and delivery at the time and place specified pursuant to this Agreement is a further condition of the obligation of each Underwriter hereunder. Upon delivery, the Selling Stockholder, shall register the Firm Stock in such names and in such denominations as the Representatives shall request in writing not less than two full business days prior to the Initial Delivery Date. For the purpose of expediting the checking and packaging of the certificates for the Firm Stock, the Selling Stockholder shall make the certificates representing the Firm Stock available for inspection by the Representatives in New York, New York, not later than 2:00 P.M., New York City time, on the business day prior to the Initial Delivery Date.

The option granted in Section 3 will expire 30 days after the date of this Agreement and may be exercised in whole or from time to time in part by written notice being given to the Selling Stockholder by the Representatives; provided that if such date falls on a day that is not a business day, the option granted in Section 3 will expire on the next succeeding business day. Such notice shall set forth the aggregate number of shares of Option Stock as to which the option is being exercised, the names in which the shares of Option Stock are to be registered, the

denominations in which the shares of Option Stock are to be issued and the date and time, as determined by the Representatives, when the shares of Option Stock are to be delivered; provided, however, that this date and time shall not be earlier than the Initial Delivery Date nor earlier than the second business day after the date on which the option shall have been exercised nor later than the fifth business day after the date on which the option shall have been exercised. Each date and time the shares of Option Stock are delivered is sometimes referred to as an “Option Stock Delivery Date,” and the Initial Delivery Date and any Option Stock Delivery Date are sometimes each referred to as a “Delivery Date.”

Delivery of the Option Stock by the Selling Stockholder and payment for the Option Stock by the several Underwriters through the Representatives shall be made at the office of Vinson & Elkins L.L.P. at 10:00 A.M., New York City time, on the date specified in the corresponding notice described in the preceding paragraph or at such other date or place as shall be determined by agreement between the Representatives and the Selling Stockholder. On the Option Stock Delivery Date, the Selling Stockholder shall deliver or cause to be delivered the Option Stock to the Representatives for the account of each Underwriter against payment by the several Underwriters through the Representatives and of the respective aggregate purchase prices of the Option Stock being sold by the Selling Stockholder of the purchase price by wire transfer in immediately available funds to the accounts specified by the Stockholder. Time shall be of the essence, and delivery at the time and place specified pursuant to this Agreement is a further condition of the obligation of each Underwriter hereunder. Upon delivery, the Selling Stockholder, shall register the Option Stock in such names and in such denominations as the Representatives shall request in writing not less than two full business days prior to the Initial Delivery Date. For the purpose of expediting the checking and packaging of the certificates for the Option Stock, the Selling Stockholder shall make the certificates representing the Firm Stock available for inspection by the Representatives in New York, New York, not later than 2:00 P.M., New York City time, on the business day prior to the Initial Delivery Date.

6. Further Agreements of the Company and the Underwriters.

(a) The Company agrees:

(i) To prepare the Prospectus in a form approved by the Representatives and to file such Prospectus pursuant to Rule 424(b) under the Securities Act not later than the Commission’s close of business on the second business day following the execution and delivery of this Agreement; to make no further amendment or any supplement to the Registration Statement or the Prospectus prior to the last Delivery Date except as provided herein; to advise the Representatives, promptly after it receives notice thereof, of the time when any amendment or supplement to the Registration Statement or the Prospectus has been filed and to furnish the Representatives with copies thereof; to file promptly all reports and any definitive proxy or information statements required to be filed by the Company with the Commission pursuant to Section 13(a), 13(c), 14 or 15(d) of the Exchange Act subsequent to the date of the Prospectus and for so long as the delivery of a prospectus is required in connection with the offering or sale of the Stock; to advise the Representatives, promptly after it receives notice thereof, of the issuance by the Commission of any stop order or of any order

preventing or suspending the use of the Prospectus or any Issuer Free Writing Prospectus, of the suspension of the qualification of the Stock for offering or sale in any jurisdiction, of the initiation or threatening of any proceeding or examination for any such purpose, of any notice from the Commission objecting to the use of the form of the Registration Statement or any post-effective amendment thereto or of any request by the Commission for the amending or supplementing of the Registration Statement, the Prospectus or any Issuer Free Writing Prospectus or for additional information; and, in the event of the issuance of any stop order or of any order preventing or suspending the use of the Prospectus or any Issuer Free Writing Prospectus or suspending any such qualification, to use promptly its best efforts to obtain its withdrawal;

(ii) To pay the applicable Commission filing fees relating to the Stock within the time required by Rule 456(b)(1) without regard to the proviso therein;

(iii) To furnish promptly to each of the Representatives and to counsel for the Underwriters a signed copy of the Registration Statement as originally filed with the Commission, and each amendment thereto filed with the Commission, including all consents and exhibits filed therewith;

(iv) To deliver promptly to the Representatives such number of the following documents as the Representatives shall reasonably request: (A) conformed copies of the Registration Statement as originally filed with the Commission and each amendment thereto (in each case excluding exhibits other than this Agreement and the computation of per share earnings), (B) each Preliminary Prospectus, the Prospectus and any amended or supplemented Prospectus, (C) each Issuer Free Writing Prospectus and (D) any document incorporated by reference in any Preliminary Prospectus or the Prospectus; and, if the delivery of a prospectus is required at any time after the date hereof in connection with the offering or sale of the Stock or any other securities relating thereto and if at such time any events shall have occurred as a result of which the Prospectus as then amended or supplemented would include an 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 when such Prospectus is delivered, not misleading, or, if for any other reason it shall be necessary to amend or supplement the Prospectus or to file under the Exchange Act any document incorporated by reference in the Prospectus in order to comply with the Securities Act or the Exchange Act, to notify the Representatives and, upon their request, to file such document and to prepare and furnish without charge to each Underwriter and to any dealer in securities as many copies as the Representatives may from time to time reasonably request of an amended or supplemented Prospectus that will correct such statement or omission or effect such compliance;

(v) To file promptly with the Commission any amendment or supplement to the Registration Statement or the Prospectus, or any additional Registration Statement and related amendment or supplement to the Prospectus in

the event that the current Registration Statement is expired, that may, in the judgment of the Company or the Representatives, be required by the Securities Act or requested by the Commission;

(vi) Prior to filing with the Commission any amendment or supplement to the Registration Statement or the Prospectus, any document incorporated by reference in the Prospectus or any amendment to any document incorporated by reference in the Prospectus, to furnish a copy thereof to the Representatives and counsel for the Underwriters and obtain the consent of the Representatives to the filing;

(vii) Not to make any offer relating to the Stock that would constitute an Issuer Free Writing Prospectus without the prior written consent of the Representatives.

(viii) To comply with all applicable requirements of Rule 433 with respect to any Issuer Free Writing Prospectus; and if at any time after the date hereof any events shall have occurred as a result of which any Issuer Free Writing Prospectus, as then amended or supplemented, would conflict with the information in the Registration Statement, the most recent Preliminary Prospectus or the Prospectus or would include an 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, or, if for any other reason it shall be necessary to amend or supplement any Issuer Free Writing Prospectus, to notify the Representatives and, upon its request, to file such document and to prepare and furnish without charge to each Underwriter as many copies as the Representatives may from time to time reasonably request of an amended or supplemented Issuer Free Writing Prospectus that will correct such conflict, statement or omission or effect such compliance;

(ix) As soon as practicable after the Effective Date and in any event not later than 16 months after the date hereof, to make generally available to the Company’s security holders and to deliver to the Representatives an earnings statement of the Company and its subsidiaries (which need not be audited) complying with Section 11(a) of the Securities Act and the Rules and Regulations;

(x) Promptly from time to time to take such action as the Representatives may reasonably request to qualify the Stock for offering and sale under the securities laws of Canada and such other jurisdictions as the Representatives may reasonably request and to comply with such laws so as to permit the continuance of sales and dealings therein in such jurisdictions for as long as may be necessary to complete the distribution of the Stock; provided that in connection therewith the Company shall not be required to (A) qualify as a foreign corporation in any jurisdiction in which it would not otherwise be required to so qualify, (B) file a general consent to service of process in any such jurisdiction or (C) subject itself to taxation in any jurisdiction in which it would not otherwise be subject;

(xi) For a period commencing on the date hereof and ending on the 30th day after the date of the Prospectus (the “Company Lock-Up Period”), not to, directly or indirectly, (A) offer for sale, sell, pledge or otherwise dispose of (or enter into any transaction or device that is designed to, or could be expected to, result in the disposition by any person at any time in the future of) any shares of Common Stock (including, without limitation, shares of Common Stock that may be deemed to be beneficially owned by the Company in accordance with the rules and regulations of the Commission and shares of Common Stock that may be issued upon exercise of any options or warrants) or securities convertible into or exercisable or exchangeable for Common Stock (other than in any case the Stock and securities issued pursuant to employee benefit plans, qualified stock option plans or other employee and non-employee director compensation plans existing on the date hereof), (B) enter into any swap or other derivatives transaction that transfers to another, in whole or in part, any of the economic benefits or risks of ownership of such shares of Common Stock, whether any such transaction described in clause (A) or (B) above is to be settled by delivery of Common Stock or other securities, in cash or otherwise, (C) make any demand for or exercise any right or cause to be filed a registration statement, including any amendments, with respect to the registration of any shares of Common Stock or securities convertible, exercisable or exchangeable into Common Stock or any other securities of the Company or (D) publicly disclose the intention to do any of the foregoing, in each case without the prior written consent of Barclays Capital Inc., on behalf of the Underwriters, and to cause each officer and director of the Company and each other party set forth on Schedule 2 hereto to furnish to Barclays Capital Inc., prior to or as of the date hereof, a letter or letters, substantially in the form of Exhibit A hereto (the “Lock-Up Agreements”);

(b) Each Underwriter severally agrees that such Underwriter shall not include any “issuer information” (as defined in Rule 433) in any “free writing prospectus” (as defined in Rule 405) used or referred to by such Underwriter without the prior consent of the Company (any such issuer information with respect to whose use the Company has given its consent, “Permitted Issuer Information”); provided that (i) no such consent shall be required with respect to any such issuer information contained in any document filed by the Company with the Commission prior to the use of such free writing prospectus and (ii) “issuer information,” as used in this Section 6(b), shall not be deemed to include information prepared by or on behalf of such Underwriter on the basis of or derived from issuer information.

7. Further Agreements of the Selling Stockholder. The Selling Stockholder agrees:

(a) For a period commencing on the date hereof and ending on the 90th day after the date of the Prospectus (the “Stockholder Lock-Up Period”), not to, directly or indirectly, (1) offer for sale, sell, pledge or otherwise dispose of (or enter into any transaction or device that is designed to, or could be expected to, result in the disposition

by any person at any time in the future of) any shares of Common Stock or securities convertible into or exchangeable for Common Stock (other than the Stock), (2) enter into any swap or other derivatives transaction that transfers to another, in whole or in part, any of the economic benefits or risks of ownership of such shares of Common Stock, whether any such transaction described in clause (1) or (2) above is to be settled by delivery of Common Stock or other securities, in cash or otherwise, (3) make any demand for or exercise any right or file or cause to be filed a registration statement, including any amendments, with respect to the registration of any shares of Common Stock or securities convertible, exercisable or exchangeable into Common Stock or any other securities of the Company or (4) publicly disclose the intention to do any of the foregoing, in each case without the prior written consent of Barclays Capital Inc., on behalf of the Underwriters.

(b) Prior to engaging in any transaction or taking any other action that is subject to the terms of Section 7(a) during the period from the date of this Agreement to and including the 34th day following the expiration of the Stockholder Lock-Up Period, it will give notice thereof to the Company and will not consummate such transaction or take any such action unless it has received written confirmation from the Company that the Stockholder Lock-Up Period (as such may have been extended pursuant to Section 7(a)) has expired.

(c) That the Stock to be sold by the Selling Stockholder hereunder is subject to the interest of the Underwriters and that the obligations of the Selling Stockholder hereunder shall not be terminated by any act of the Selling Stockholder, by operation of law or the occurrence of any other event.

(d) Neither the Selling Stockholder nor any person acting on behalf of the Selling Stockholder (other than, if applicable, the Company and the Underwriters) shall use or refer to any “free writing prospectus” (as defined in Rule 405), relating to the Stock;

(e) To deliver to the Representatives prior to the Initial Delivery Date a properly completed and executed United States Treasury Department Form W-8 (if the Selling Stockholder is a non-United States person) or Form W-9 (if the Selling Stockholder is a United States person).

8. Expenses. The Company agrees, whether or not the transactions contemplated by this Agreement are consummated or this Agreement is terminated, to pay all costs, expenses, fees and taxes incident to and in connection with (a) the sale and delivery of the Common Stock and any stamp duties or other taxes payable in that connection, and the preparation and printing of certificates for the Stock; (b) the preparation, printing and filing under the Securities Act of the Registration Statement (including any exhibits thereto), any Preliminary Prospectus, the Prospectus, any Issuer Free Writing Prospectus and any amendment or supplement thereto; (c) the distribution of the Registration Statement (including any exhibits thereto), any Preliminary Prospectus, the Prospectus, any Issuer Free Writing Prospectus and any amendment or supplement thereto, or any document incorporated by reference therein, all as provided in this Agreement; (d) the production and distribution of this Agreement, any supplemental agreement

among Underwriters, and any other related documents in connection with the offering, purchase, sale and delivery of the Stock; (e) any required review by the Financial Industry Regulatory Authority of the terms of sale of the Stock (including related fees and expenses of counsel to the Underwriters); (f) the listing of the Stock on the New York Stock Exchange; (g) the qualification of the Stock under the securities laws of the several jurisdictions as provided in Section 6(a)(x) and the preparation, printing and distribution of a Blue Sky Memorandum (including related fees and expenses of counsel to the Underwriters); (h) the preparation, printing and distribution of one or more versions of the Preliminary Prospectus and the Prospectus for distribution in Canada, often in the form of a Canadian “wrapper” (including related fees and expenses of Canadian counsel to the Underwriters); (i) reasonable expenses associated with the investor presentations on any “road show” undertaken in connection with the marketing of the Common Stock, including, without limitation, expenses associated with any electronic road show, travel and lodging expenses of the representatives and officers of the Company, and the cost of any aircraft chartered in connection with the road show; and (j) all other costs and expenses incident to the performance of the obligations of the Company and the Selling Stockholder; provided that, except as provided in this Section 8 and in Section 13, (A) the Underwriters shall pay their own costs and expenses, including the costs and expenses of their counsel, any transfer taxes on the Stock which they may sell and the expenses of advertising any offering of the Stock made by the Underwriters and (B) the Selling Stockholder shall pay the costs and expenses of their legal counsel and any underwriting discounts and commissions relating to the sale of the Stock.

9. Conditions of Underwriters’ Obligations. The respective obligations of the Underwriters hereunder are subject to the accuracy, when made and on each Delivery Date, of the representations and warranties of the Company and the Selling Stockholder contained herein, to the performance by the Company and the Selling Stockholder of its obligations hereunder, and to each of the following additional terms and conditions:

(a) The Prospectus shall have been timely filed with the Commission in accordance with Section 6(a)(i); the Company shall have complied with all filing requirements applicable to any Issuer Free Writing Prospectus used or referred to after the date hereof; no stop order suspending the effectiveness of the Registration Statement or preventing or suspending the use of the Prospectus or any Issuer Free Writing Prospectus shall have been issued and no proceeding or examination for such purpose shall have been initiated or threatened by the Commission; any request of the Commission for inclusion of additional information in the Registration Statement or the Prospectus or otherwise shall have been complied with; and the Commission shall not have notified the Company of any objection to the use of the form of the Registration Statement.

(b) No Underwriter shall have discovered and disclosed to the Company on or prior to such Delivery Date that the Registration Statement, the Prospectus or the Pricing Disclosure Package, or any amendment or supplement thereto, contains an untrue statement of a fact which, in the opinion of Vinson & Elkins L.L.P., counsel for the Underwriters, is material or omits to state a fact which, in the opinion of such counsel, is material and is required to be stated therein or is necessary to make the statements therein not misleading.

(c) All corporate proceedings and other legal matters incident to the authorization, form and validity of this Agreement, the Stock, the Registration Statement, the Prospectus and any Issuer Free Writing Prospectus, and all other legal matters relating to this Agreement and the transactions contemplated hereby shall be reasonably satisfactory in all material respects to counsel for the Underwriters, the Company and the Selling Stockholder shall have furnished to such counsel all documents and information that they may reasonably request to enable them to pass upon such matters.

(d) Thompson & Knight LLP shall have furnished to the Representatives its written opinion, as counsel to the Company, addressed to the Underwriters and dated such Delivery Date, in form and substance reasonably satisfactory to the Representatives, substantially in the form attached hereto as Exhibit B-1.

(e) David Elkouri, General Counsel of the Company shall have furnished to the Representatives his written opinion, as counsel to the Company, addressed to the Underwriters and dated such Delivery Date, in form and substance reasonably satisfactory to the Representatives, substantially in the form attached hereto as Exhibit B-2.

(f) Thompson & Knight LLP, counsel for the Selling Stockholders shall have furnished to the Representatives its written opinion, as counsel to the Selling Stockholder for whom it is acting as counsel, addressed to the Underwriters and dated such Delivery Date, in form and substance reasonably satisfactory to the Representatives, substantially in the form attached hereto as Exhibit B-3.

(g) The Representatives shall have received from Vinson & Elkins L.L.P., counsel for the Underwriters, such opinion or opinions, dated such Delivery Date, with respect to the sale of the Stock, the Registration Statement, the Prospectus and the Pricing Disclosure Package and other related matters as the Representatives 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) At the time of execution of this Agreement, the Representatives shall have received from each of (a) Deloitte & Touche LLP, (b) UHY LLC and (c) Grant Thornton LLP a letter, in form and substance satisfactory to the Representatives, addressed to the Representatives and dated the date hereof (i) confirming that they are independent public accountants within the meaning of the Securities Act and are in compliance with the applicable requirements relating to the qualification of accountants under Rule 2-01 of Regulation S-X of the Commission and (ii) stating, as of the date hereof (or, with respect to matters involving changes or developments since the respective dates as of which specified financial information is given in the Pricing Disclosure Package, as of a date not more than three days prior to the date hereof), the conclusions and findings of such firm with respect to the financial information and (iii) covering such other matters as are ordinarily covered by accountants’ “comfort letters” to underwriters in connection with registered public offerings.

(i) With respect to the letters of each of (a) Deloitte & Touche LLP, (b) UHY LLC and (c) Grant Thornton LLP referred to in the preceding paragraph and delivered to the Representatives concurrently with the execution of this Agreement (each, an “initial letter”), the Company shall have furnished to the Representatives a “bring-down letter” of such accountants, addressed to the Representatives and dated the Closing Date (i) confirming that they are independent public accountants within the meaning of the Securities Act and are in compliance with the applicable requirements relating to the qualification of accountants under Rule 2-01 of Regulation S-X of the Commission, (ii) stating, as of the Closing Date (or, with respect to matters involving changes or developments since the respective dates as of which specified financial information is given in each of the Pricing Disclosure Package or the Prospectus, as of a date not more than three days prior to the date of the Closing Date), the conclusions and findings of such firm with respect to the financial information and other matters covered by the initial letter, and (iii) confirming in all material respects the conclusions and findings set forth in the initial letter.

(j) At the time of execution of this Agreement, the Representatives shall have received from each of (a) Forrest A. Garb & Associates and (b) Cawley Gillespie & Associates, Inc. an initial letter (each, an “initial expert letter”), in form and substance satisfactory to the Representatives, addressed to the Representatives and dated the date hereof and a subsequent letter dated as of the Closing Date, which such letter shall cover the period from any initial expert letter to the Closing Date, confirming that they are independent with respect to the Company and stating the conclusions and findings of such firm with respect to matters pertaining to the Company’s use of the reports of proved reserves from Forrest A. Garb & Associates and GeoResources’ use of the reports of proved reserves from Cawley Gillespie & Associates, Inc. as is customary to underwriters in connection with similar transactions.

(k) The Company shall have furnished to the Representatives a certificate, dated such Delivery Date, of its Chief Executive Officer and its Chief Financial Officer stating that:

(i) The representations, warranties and agreements of the Company in Section 1 are true and correct on and as of such Delivery Date, and the Company has complied with all its agreements contained herein and satisfied all the conditions on its part to be performed or satisfied hereunder at or prior to such Delivery Date;

(ii) No stop order suspending the effectiveness of the Registration Statement has been issued; no proceedings or examination for that purpose have been instituted or, to the knowledge of such officers, threatened; and the Commission has not notified the Company of any objection to the use of the form of the Registration Statement or any post-effective amendment thereto; and

(iii) They have carefully examined the Registration Statement, the Prospectus and the Pricing Disclosure Package, and, in their opinion, (A) (1) the Registration Statement, as of the Effective Date, (2) the Prospectus, as of its date

and on the applicable Delivery Date, or (3) the Pricing Disclosure Package, as of the Applicable Time, did not and do not contain any untrue statement of a material fact and did not and do not omit to state a material fact required to be stated therein or necessary to make the statements therein (except in the case of the Registration Statement, in the light of the circumstances under which they were made) not misleading, and (B) since the Effective Date, no event has occurred that should have been set forth in a supplement or amendment to the Registration Statement, the Prospectus or any Issuer Free Writing Prospectus that has not been so set forth;

(l) The Selling Stockholder shall have furnished to the Representatives on such Delivery Date a certificate, dated such Delivery Date, signed by, or on behalf of, the Selling Stockholder stating that the representations, warranties and agreements of the Selling Stockholder contained herein are true and correct on and as of such Delivery Date and that the Selling Stockholder has complied with all its agreements contained herein and has satisfied all the conditions on its part to be performed or satisfied hereunder at or prior to such Delivery Date.

(m) The Selling Stockholder shall have furnished to the Representatives on such Delivery Date a certificate, dated such Delivery Date, signed by, or on behalf of, such Selling Stockholder stating that such Selling Stockholder has carefully examined the Selling Stockholder Information contained in the Registration Statement, the Prospectus and the Pricing Disclosure Package, and that the representations and warranties of such Selling Stockholder in this Agreement are true and correct in all material respects on and as of the appropriate Delivery Date to the same effect as if made on such Delivery Date.

(n) Except as described in the most recent Preliminary Prospectus and the Pricing Disclosure Package, (i) neither the Company nor any of its subsidiaries shall have sustained, since the date of the latest audited financial statements included or incorporated by reference in the most recent Preliminary Prospectus, any loss or interference with its business from fire, explosion, flood or other calamity, whether or not covered by insurance, or from any labor dispute or court or governmental action, order or decree or (ii) since such date there shall not have been any change in the capital stock or long-term debt of the Company or any of its subsidiaries or any change, or any development involving a prospective change, in or affecting the condition (financial or otherwise), results of operations, stockholders’ equity, properties, management, business or prospects of the Company and its subsidiaries taken as a whole, the effect of which, in any such case described in clause (i) or (ii), is, in the judgment of the Representatives, so material and adverse as to make it impracticable or inadvisable to proceed with the public offering or the delivery of the Stock being delivered on such Delivery Date on the terms and in the manner contemplated in the Prospectus.

(o) Subsequent to the execution and delivery of this Agreement (i) no downgrading shall have occurred in the rating accorded the Company’s debt securities or preferred stock by any “nationally recognized statistical rating organization” (as that term is defined by the Commission for purposes of Rule 436(g)(2) of the Rules and Regulations), and (ii) no such organization shall have publicly announced that it has under surveillance or review, with possible negative implications, its rating of any of the Company’s debt securities or preferred stock.

(p) Subsequent to the execution and delivery of this Agreement there shall not have occurred any of the following: (i) trading in securities generally on the New York Stock Exchange or the American Stock Exchange or in the over-the-counter market, or trading in any securities of the Company on any exchange or in the over-the-counter market, shall have been suspended or materially limited or the settlement of such trading generally shall have been materially disrupted or minimum prices shall have been established on any such exchange or such market by the Commission, by such exchange or by any other regulatory body or governmental authority having jurisdiction, (ii) a banking moratorium shall have been declared by federal or state authorities, (iii) the United States shall have become engaged in hostilities, there shall have been an escalation in hostilities involving the United States or there shall have been a declaration of a national emergency, calamity, crisis or war by the United States or (iv) there shall have occurred such a material adverse change in general economic, political or financial conditions, including, without limitation, as a result of terrorist activities after the date hereof (or the effect of international conditions on the financial markets in the United States shall be such), as to make it, in the judgment of the Representatives, impracticable or inadvisable to proceed with the public offering or delivery of the Stock being delivered on such Delivery Date on the terms and in the manner contemplated in the Prospectus.

(q) The Lock-Up Agreements between Barclays Capital Inc. and the officers and directors of the Company and the other parties set forth on Schedule 2, delivered to Barclays Capital Inc. on or before the date of this Agreement, shall be in full force and effect on such Delivery Date.

All opinions, letters, evidence and certificates mentioned above or elsewhere in this Agreement shall be deemed to be in compliance with the provisions hereof only if they are in form and substance reasonably satisfactory to counsel for the Underwriters.

10. Indemnification and Contribution.

(a) The Company shall indemnify and hold harmless each Underwriter, its affiliates, directors, officers and employees and each person, if any, who controls any Underwriter within the meaning of Section 15 of the Securities Act, from and against any loss, claim, damage or liability, joint or several, or any action in respect thereof (including, but not limited to, any loss, claim, damage, liability or action relating to purchases and sales of Stock), to which that Underwriter, affiliate, director, officer, employee or controlling person may become subject, under the Securities Act or otherwise, insofar as such loss, claim, damage, liability or action arises out of, or is based upon, (i) any untrue statement or alleged untrue statement of a material fact contained in (A) any Preliminary Prospectus, the Registration Statement, the Prospectus or in any amendment or supplement thereto, (B) any Issuer Free Writing Prospectus or in any amendment or supplement thereto or (C) any Permitted Issuer Information used or referred to in any “free writing prospectus” (as defined in Rule 405) used or referred to by any Underwriter, or (D) any Blue Sky application or other document prepared or

executed by the Company (or based upon any written information furnished by the Company for use therein) specifically for the purpose of qualifying any or all of the Stock under the securities laws of any state or other jurisdiction (any such application, document or information being hereinafter called a “Blue Sky Application”) or (ii) the omission or alleged omission to state in any Preliminary Prospectus, the Registration Statement, the Prospectus, any Issuer Free Writing Prospectus or in any amendment or supplement thereto or in any Permitted Issuer Information, or any Blue Sky Application, any material fact required to be stated therein or necessary to make the statements therein not misleading, and shall reimburse each Underwriter and each such director, officer, employee or controlling person promptly upon demand for any legal or other expenses reasonably incurred by that Underwriter, director, officer, employee or controlling person in connection with investigating or defending or preparing to defend against any such loss, claim, damage, liability or action as such expenses are incurred; provided, however, that the Company shall not be liable in any such case to the extent that any such loss, claim, damage, liability or action arises out of, or is based upon, any untrue statement or alleged untrue statement or omission or alleged omission made in any Preliminary Prospectus, the Registration Statement, the Prospectus, any Issuer Free Writing Prospectus or in any such amendment or supplement thereto or in any Permitted Issuer Information, or any Blue Sky Application, in reliance upon and in conformity with written information concerning such Underwriter furnished to the Company through the Representatives by or on behalf of any Underwriter specifically for inclusion therein, which information consists solely of the information specified in Section 10(f). The foregoing indemnity agreement is in addition to any liability which the Company may otherwise have to any Underwriter or to any director, officer, employee or controlling person of that Underwriter.

(b) The Selling Stockholder shall indemnify and hold harmless each Underwriter, its directors, officers and employees, and each person, if any, who controls any Underwriter within the meaning of Section 15 of the Securities Act, from and against any loss, claim, damage or liability, joint or several, or any action in respect thereof (including, but not limited to, any loss, claim, damage, liability or action relating to purchases and sales of Stock), to which that Underwriter, director, officer, employee or controlling person may become subject, under the Securities Act or otherwise, insofar as such loss, claim, damage, liability or action arises out of, or is based upon, (i) any untrue statement or alleged untrue statement of a material fact contained in any Preliminary Prospectus, the Registration Statement, the Prospectus, any Issuer Free Writing Prospectus or in any amendment or supplement thereto or in any Permitted Issuer Information, any Non-Prospectus Road Show, any Blue Sky Application or any “free writing prospectus” (as defined in Rule 405), prepared by or on behalf of the Selling Stockholder or used or referred to by the Selling Stockholder in connection with the offering of the Stock in violation of Section 7(d) (a “Selling Stockholder Free Writing Prospectus”), (ii) the omission or alleged omission to state in any Preliminary Prospectus, Registration Statement, the Prospectus, any Issuer Free Writing Prospectus or in any amendment or supplement thereto or in any Permitted Issuer Information, any Non-Prospectus Road Show, any Blue Sky Application or any Selling Stockholder Free Writing Prospectus, any material fact required to be stated therein or necessary to make the statements therein not misleading, and shall reimburse each Underwriter, its directors,

officers and employees and each such controlling person promptly upon demand for any legal or other expenses reasonably incurred by that Underwriter, its directors, officers and employees or controlling persons in connection with investigating or defending or preparing to defend against any such loss, claim, damage, liability or action as such expenses are incurred or (iii) any breach of any representation or warranty of the Selling Stockholders in this Agreement or any certificate or other agreement delivered pursuant hereto or contemplated hereby, but in each case under clauses (i), (ii) or (iii) only to the extent that such untrue statement or alleged untrue statement or omission or alleged omission was made in reliance upon and in conformity with the Selling Stockholder Information. The liability of the Selling Stockholder under the indemnity agreement contained in this paragraph shall be limited to an amount equal to the total gross proceeds from the offering of the shares of the Stock purchased under the Agreement received by the Selling Stockholder, as set forth in the table on the cover page of the Prospectus. The foregoing indemnity agreement is in addition to any liability that the Selling Stockholder may otherwise have to any Underwriter or any officer, employee or controlling person of that Underwriter

(c) Each Underwriter, severally and not jointly, shall indemnify and hold harmless the Company, the Selling Stockholder and each of their respective officers and employees, within the meaning of Section 15 of the Securities Act, from and against any loss, claim, damage or liability, joint or several, or any action in respect thereof, to which the Company or any such director, officer, employee or controlling person may become subject, under the Securities Act or otherwise, insofar as such loss, claim, damage, liability or action arises out of, or is based upon, (i) any untrue statement or alleged untrue statement of a material fact contained in any Preliminary Prospectus, the Registration Statement, the Prospectus, any Issuer Free Writing Prospectus or in any amendment or supplement thereto or Blue Sky Application, or (ii) the omission or alleged omission to state in any Preliminary Prospectus, the Registration Statement, the Prospectus, any Issuer Free Writing Prospectus or in any amendment or supplement thereto or Blue Sky Application, any material fact required to be stated therein or necessary to make the statements therein not misleading, but in each case only to the extent that the untrue statement or alleged untrue statement or omission or alleged omission was made in reliance upon and in conformity with written information concerning such Underwriter furnished to the Company through the Representatives by or on behalf of that Underwriter specifically for inclusion therein, which information is limited to the information set forth in Section 10(f). The foregoing indemnity agreement is in addition to any liability that any Underwriter may otherwise have to the Company or any such director, officer, employee or controlling person.

(d) Promptly after receipt by an indemnified party under this Section 10 of notice of any claim or the commencement of any action, the indemnified party shall, if a claim in respect thereof is to be made against the indemnifying party under Section 10(a) or 10(b), notify the indemnifying party in writing of the claim or the commencement of that action; provided, however, that the failure to notify the indemnifying party shall not relieve it from any liability which it may have under Section 10(a) or 10(b) except to the extent it has been materially prejudiced by such failure and, provided, further, that the failure to notify the indemnifying party shall not relieve it from any liability which it may

have to an indemnified party otherwise than under this Section 10. If any such claim or action shall be brought against an indemnified party, and it shall notify the indemnifying party thereof, the indemnifying party shall be entitled to participate therein and, to the extent that it wishes, jointly with any other similarly notified indemnifying party, to assume the defense thereof with counsel reasonably satisfactory to the indemnified party. After notice from the indemnifying party to the indemnified party of its election to assume the defense of such claim or action, the indemnifying party shall not be liable to the indemnified party under this Section 10 for any legal or other expenses subsequently incurred by the indemnified party in connection with the defense thereof other than reasonable costs of investigation; provided, however, that the indemnified party shall have the right to employ counsel to represent jointly the indemnified party and those other indemnified parties and their respective directors, officers, employees and controlling persons who may be subject to liability arising out of any claim in respect of which indemnity may be sought under this Section 10 if (i) the indemnified party and the indemnifying party shall have so mutually agreed; (ii) the indemnifying party has failed within a reasonable time to retain counsel reasonably satisfactory to the indemnified party; (iii) the indemnified party and its directors, officers, employees and controlling persons shall have reasonably concluded that there may be legal defenses available to them that are different from or in addition to those available to the indemnifying party; or (iv) the named parties in any such proceeding (including any impleaded parties) include both the indemnified parties or their respective directors, officers, employees or controlling persons, on the one hand, and the indemnifying party, on the other hand, and representation of both sets of parties by the same counsel would be inappropriate due to actual or potential differing interests between them, and in any such event the fees and expenses of such separate counsel shall be paid by the indemnifying party. No indemnifying party shall (i) without the prior written consent of the indemnified parties, settle or compromise or consent to the entry of any judgment with respect to any pending or threatened claim, action, suit or proceeding in respect of which indemnification or contribution may be sought hereunder (whether or not the indemnified parties are actual or potential parties to such claim or action) unless such settlement, compromise or consent includes an unconditional release of each indemnified party from all liability arising out of such claim, action, suit or proceeding and does not include any findings of fact or admissions of fault or culpability as to the indemnified party, or (ii) be liable for any settlement of any such action effected without its written consent (which consent shall not be unreasonably withheld), but if settled with the consent of the indemnifying party or if there be a final judgment for the plaintiff in any such action, the indemnifying party agrees to indemnify and hold harmless any indemnified party from and against any loss or liability by reason of such settlement or judgment.

(e) If the indemnification provided for in this Section 10 shall for any reason be unavailable to or insufficient to hold harmless an indemnified party under Section 10(a) or 10(b) in respect of any loss, claim, damage or liability, or any action in respect thereof, referred to therein, then each indemnifying party shall, in lieu of indemnifying such indemnified party, contribute to the amount paid or payable by such indemnified party as a result of such loss, claim, damage or liability, or action in respect thereof, (i) in such proportion as shall be appropriate to reflect the relative benefits received by the Company and the Selling Stockholder, on the one hand, and the

Underwriters, on the other, from the offering of the Stock 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 Selling Stockholder, on the one hand, and the Underwriters, on the other, with respect to the statements or omissions that resulted in such loss, claim, damage or liability, or action in respect thereof, as well as any other relevant equitable considerations. The relative benefits received by the Company and the Selling Stockholder, on the one hand, and the Underwriters, on the other, with respect to such offering shall be deemed to be in the same proportion as the total net proceeds from the offering of the Stock purchased under this Agreement (before deducting expenses) received by the Company and the Selling Stockholder, as set forth in the table on the cover page of the Prospectus, on the one hand, and the total underwriting discounts and commissions received by the Underwriters with respect to the shares of the Stock purchased under this Agreement, as set forth in the table on the cover page of the Prospectus, on the other hand. The relative fault shall be determined by reference to whether the untrue or alleged untrue statement of a material fact or omission or alleged omission to state a material fact relates to information supplied by the Company, the Selling Stockholderor the Underwriters, the intent of the parties and their relative knowledge, access to information and opportunity to correct or prevent such statement or omission. The Company, the Selling Stockholder and the Underwriters agree that it would not be just and equitable if contributions pursuant to this Section 10(e) were to be determined by pro rata allocation (even if the Underwriters were treated as one entity for such purpose) or by any other method of allocation that does not take into account the equitable considerations referred to herein. The amount paid or payable by an indemnified party as a result of the loss, claim, damage or liability, or action in respect thereof, referred to above in this Section 10(e) shall be deemed to include, for purposes of this Section 10(e), any legal or other expenses reasonably incurred by such indemnified party in connection with investigating or defending any such action or claim. Notwithstanding the provisions of this Section 10(e), no Underwriter shall be required to contribute any amount in excess of the amount by which the Stock underwritten by it exceeds the amount of any damages that such Underwriter has otherwise paid or become liable to pay by reason of any untrue or alleged untrue statement or omission or alleged omission. No person guilty of fraudulent misrepresentation (within the meaning of Section 9(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 as provided in this Section 10(e) are several in proportion to their respective underwriting obligations and not joint.

(f) The Underwriters severally confirm and the Company and the Selling Stockholder acknowledges and agrees that the statements regarding delivery of shares by the Underwriters set forth on the cover page of, and the concession and reallowance figures and the paragraph relating to stabilization, short positions and penalty bids by the Underwriters appearing under the caption “Underwriting” in, the most recent Preliminary Prospectus and the Prospectus are correct and constitute the only information concerning such Underwriters furnished in writing to the Company by or on behalf of the Underwriters specifically for inclusion in any Preliminary Prospectus, the Registration Statement, the Prospectus, any Issuer Free Writing Prospectus or in any amendment or supplement thereto.

11. Defaulting Underwriters. If, on any Delivery Date, any Underwriter defaults in the performance of its obligations under this Agreement, the remaining non-defaulting Underwriters shall be obligated to purchase the Stock that the defaulting Underwriter agreed but failed to purchase on such Delivery Date in the respective proportions which the number of shares of the Firm Stock set forth opposite the name of each remaining non-defaulting Underwriter in Schedule 1 hereto bears to the total number of shares of the Firm Stock set forth opposite the names of all the remaining non-defaulting Underwriters in Schedule 1 hereto; provided, however, that the remaining non-defaulting Underwriters shall not be obligated to purchase any of the Stock on such Delivery Date if the total number of shares of the Stock that the defaulting Underwriter or Underwriters agreed but failed to purchase on such date exceeds 9.09% of the total number of shares of the Stock to be purchased on such Delivery Date, and any remaining non-defaulting Underwriter shall not be obligated to purchase more than 110% of the number of shares of the Stock that it agreed to purchase on such Delivery Date pursuant to the terms of Section 3. If the foregoing maximums are exceeded, the remaining non-defaulting Underwriters, or those other underwriters satisfactory to the Representatives who so agree, shall have the right, but shall not be obligated, to purchase, in such proportion as may be agreed upon among them, all the Stock to be purchased on such Delivery Date. If the remaining Underwriters or other underwriters satisfactory to the Representatives do not elect to purchase the shares that the defaulting Underwriter or Underwriters agreed but failed to purchase on such Delivery Date, this Agreement (or, with respect to any Option Stock Delivery Date, the obligation of the Underwriters to purchase, and of the Selling Stockholder to sell, the Option Stock) shall terminate without liability on the part of any non-defaulting Underwriter or the Company, except that the Company will continue to be liable for the payment of expenses to the extent set forth in Sections 8 and 13. As used in this Agreement, the term “Underwriter” includes, for all purposes of this Agreement unless the context requires otherwise, any party not listed in Schedule 1 hereto that, pursuant to this Section 11, purchases Stock that a defaulting Underwriter agreed but failed to purchase.

Nothing contained herein shall relieve a defaulting Underwriter of any liability it may have to the Company for damages caused by its default. If other Underwriters are obligated or agree to purchase the Stock of a defaulting or withdrawing Underwriter, either the Representatives or the Company may postpone the Delivery Date for up to seven full business days in order to effect any changes that in the opinion of counsel for the Company or counsel for the Underwriters may be necessary in the Registration Statement, the Prospectus or in any other document or arrangement.

12. Termination. The obligations of the Underwriters hereunder may be terminated by the Representatives by notice given to and received by the Company and the Selling Stockholder prior to delivery of and payment for the Firm Stock if, prior to that time, any of the events described in Sections 9(n), 9(o) and 9(p) shall have occurred or if the Underwriters shall decline to purchase the Stock for any reason permitted under this Agreement.

13. Reimbursement of Underwriters’ Expenses. If (a) the Selling Stockholder shall fail to tender the Stock for delivery to the Underwriters for any reason or (b) the Underwriters

shall decline to purchase the Stock for any reason permitted under this Agreement, the Company will reimburse the Underwriters for all reasonable out-of-pocket expenses (including fees and disbursements of counsel) incurred by the Underwriters in connection with this Agreement and the proposed purchase of the Stock, and upon demand the Company shall pay the full amount thereof to the Representatives. If this Agreement is terminated pursuant to Section 11 by reason of the default of one or more Underwriters, neither the Company nor the Selling Stockholder shall be obligated to reimburse any defaulting Underwriter on account of those expenses.

14. Research Analyst Independence. The Company acknowledges that the Underwriters’ research analysts and research departments are required to be independent from their respective investment banking divisions and are subject to certain regulations and internal policies, and that such Underwriters’ research analysts may hold views and make statements or investment recommendations and/or publish research reports with respect to the Company and/or the offering that differ from the views of their respective investment banking divisions. The Company and the Selling Stockholder hereby waives and releases, to the fullest extent permitted by law, any claims that the Company or the Selling Stockholder may have against the Underwriters with respect to any conflict of interest that may arise from the fact that the views expressed by their independent research analysts and research departments may be different from or inconsistent with the views or advice communicated to the Company or the Selling Stockholder by such Underwriters’ investment banking divisions. The Company and the Selling Stockholder acknowledges that each of the Underwriters is a full service securities firm and as such from time to time, subject to applicable securities laws, may effect transactions for its own account or the account of its customers and hold long or short positions in debt or equity securities of the companies that may be the subject of the transactions contemplated by this Agreement.

15. No Fiduciary Duty. The Company and the Selling Stockholder acknowledges and agrees that in connection with this offering, sale of the Stock or any other services the Underwriters may be deemed to be providing hereunder, notwithstanding any preexisting relationship, advisory or otherwise, between the parties or any oral representations or assurances previously or subsequently made by the Underwriters: (a) no fiduciary or agency relationship between the Company, the Selling Stockholder and any other person, on the one hand, and the Underwriters, on the other, exists; (b) the Underwriters are not acting as advisors, expert or otherwise, to the Company or the Selling Stockholder, including, without limitation, with respect to the determination of the public offering price of the Stock, and such relationship between the Company and the Selling Stockholder, on the one hand, and the Underwriters, on the other, is entirely and solely commercial, based on arms-length negotiations; (c) any duties and obligations that the Underwriters may have to the Company and the Selling Stockholder shall be limited to those duties and obligations specifically stated herein; and (d) the Underwriters and their respective affiliates may have interests that differ from those of the Company and the Selling Stockholder. The Company and the Selling Stockholder hereby waives any claims that the Company or the Selling Stockholder may have against the Underwriters with respect to any breach of fiduciary duty in connection with this offering.

16. Notices, Etc. All statements, requests, notices and agreements hereunder shall be in writing, and:

(a) if to the Underwriters, shall be delivered or sent by mail or facsimile transmission to Barclays Capital Inc., 1271 Avenue of the Americas, 42nd Fl, New York, New York 10020, Attention: Syndicate Registration (Fax: 646 ###-###-####), with a copy, in the case of any notice pursuant to Section 10(b), to the Director of Litigation, Office of the General Counsel, Barclays Capital Inc., 1271 Avenue of the Americas, 44th floor, New York, New York 10020 (Fax: 212 ###-###-####);

(b) if to the Company, shall be delivered or sent by mail, telex or overnight courier to Halcón Resources Corporation, 1000 Louisiana Street, Suite 6700, Houston, Texas 77002, Attention: Floyd Wilson, with a copy to Thompson & Knight LLP, 333 Clay Street, Suite 3300, Houston, Texas 77002, Attention: William T. Heller IV; and

(c) if to the Selling Stockholder, shall be delivered or sent by mail, telex or overnight courier to Thompson & Knight LLP, 333 Clay Street, Suite 3300, Houston, TX 77002, Attention: Sarah E. McLean.

Any such statements, requests, notices or agreements shall take effect at the time of receipt thereof. The Company and the Selling Stockholders shall be entitled to act and rely upon any request, consent, notice or agreement given or made on behalf of the Underwriters by the Representatives.

In accordance with the requirements of the USA Patriot Act (Title III of Pub. L. 107-56 (signed into law October 26, 2011)), the Underwriters are required to obtain, verify and record information that identifies their respective clients, including the Company and the Selling Stockholder, which may include the name and address of their respective clients, as well as other information that will allow the Underwriters to properly identify their respective clients.

17. Persons Entitled to Benefit of Agreement. This Agreement shall inure to the benefit of and be binding upon the Underwriters, the Company, the Selling Stockholder and their respective successors. This Agreement and the terms and provisions hereof are for the sole benefit of only those persons, except that (a) the representations, warranties, indemnities and agreements of the Company and the Selling Stockholder contained in this Agreement shall also be deemed to be for the benefit of the affiliates, directors, officers and employees of the Underwriters and each person or persons, if any, who control any Underwriter within the meaning of Section 15 of the Securities Act and (b) the indemnity agreement of the Underwriters contained in Section 10(b) of this Agreement shall be deemed to be for the benefit of the directors of the Company, the officers of the Company who have signed the Registration Statement and any person controlling the Company within the meaning of Section 15 of the Securities Act. Nothing in this Agreement is intended or shall be construed to give any person, other than the persons referred to in this Section 17, any legal or equitable right, remedy or claim under or in respect of this Agreement or any provision contained herein.

18. Survival. The respective indemnities, representations, warranties and agreements of the Company, the Selling Stockholder and the Underwriters contained in this Agreement or made by or on behalf of them, respectively, pursuant to this Agreement, shall survive the delivery of and payment for the Stock and shall remain in full force and effect, regardless of any investigation made by or on behalf of any of them or any person controlling any of them.

19. Definition of the Terms “Business Day” and “Subsidiary”. For purposes of this Agreement, (a) “business day” means each Monday, Tuesday, Wednesday, Thursday or Friday that is not a day on which banking institutions in New York are generally authorized or obligated by law or executive order to close and (b) “subsidiary” has the meaning set forth in Rule 405.

20. Governing Law. This Agreement and any claim, controversy or dispute relating to or arising under this Agreement shall be governed by and construed in accordance with the laws of the State of New York.

21. Counterparts. This Agreement may be executed in one or more counterparts and, if executed in more than one counterpart, the executed counterparts shall each be deemed to be an original but all such counterparts shall together constitute one and the same instrument.

22. Headings. The headings herein are inserted for convenience of reference only and are not intended to be part of, or to affect the meaning or interpretation of, this Agreement.

If the foregoing correctly sets forth the agreement between the Company, the Selling Stockholder and the Underwriters, please indicate your acceptance in the space provided for that purpose below.


Very truly yours,

HALCÓN RESOURCES CORPORATION

By:		/s/ Floyd C. Wilson
		Name: Floyd C. Wilson
		Title: Chief Executive Officer

ENCAP ENERGY CAPITAL FUND VIII, L.P.

By:		/s/ David B. Miller
		Name: David B. Miller
		Title: Managing Partner

Accepted:

BARCLAYS CAPITAL INC.

GOLDMAN, SACHS & CO.

J.P. MORGAN SECURITIES LLC

For themself and as Representative

of the several Underwriters named

in Schedule 1 hereto


By:		BARCLAYS CAPITAL INC.

By:		/s/ Victoria Hale
		Authorized Representative

By:		GOLDMAN, SACHS & CO.

By:		/s/ Adam T. Greene
		Authorized Representative

By:		J.P. MORGAN SECURITIES LLC

By:		/s/ Yaw Asamoah-Duodu
		Authorized Representative

SCHEDULE 1


UNDERWRITER	NUMBER OF SHARES
Barclays Capital Inc.		10,850,000
Goldman, Sachs & Co.		7,000,000
J.P. Morgan Securities LLC		7,000,000
BMO Capital Markets Corp.		1,750,000
Credit Suisse Securities (USA) LLC		1,750,000
RBC Capital Markets, LLC		1,750,000
Wells Fargo Securities, LLC		1,750,000
Tudor, Pickering, Holt & Co. Securities, Inc.		1,050,000
Capital One Southcoast, Inc.		420,000
Howard Weil Incorporated		420,000
Johnson Rice & Company L.L.C.		420,000
Stephens Inc.		420,000
Wunderlich Securities, Inc.		420,000

Total		35,000,000

SCHEDULE 2

PERSONS DELIVERING LOCK-UP AGREEMENTS

HALRES LLC

Directors

Floyd C. Wilson

Tucker S. Birdwell

James W. Christmas

Thomas R. Fuller

James L. Irish

E. Murphy Markham IV

David B. Miller

Daniel A. Rioux

Stephen P. Smiley

Mark A. Welsh IV

Michael A. Vlasic

Officers

Floyd C. Wilson

Stephen W. Herrod

Mark J. Mize

Robert J. Anderson

David S. Elkouri

Mary Ellen Brook

Jason Brown

Leah Kasparek

Joseph Rinando

David Tippett

Jon Wright

Scott Zuehlke

Richard DiMichele

James Stubbs

SCHEDULE 3


1.	Public offering price:	Price per share to be agreed prior to the Applicable Time and will be set forth in the Prospectus

2.	Number of shares offered:	35,000,000 shares (Firm Stock) 5,250,000 shares (Option Stock)

3.	Settlement Date:	September 18, 2012

SCHEDULE 4

ISSUER FREE WRITING PROSPECTUSES

None.

SCHEDULE 5

SIGNIFICANT SUBSIDIARIES OF THE COMPANY


SUBSIDIARY		JURISDICTION OF FORMATION

Great Plains Pipeline Company		Delaware

Halcón Energy Properties, Inc.		Delaware

Halcón Field Services, LLC		Delaware

Halcón Holdings, Inc.		Delaware

Halcón Operating Co., Inc.		Texas

Halcón Resources Operating, Inc.		Delaware

Halcón Louisiana Operating, L.P.		Delaware

HLP Gulf States, LLC		Oklahoma

HRC Energy Holdings (LA), Inc.		Delaware

HRC Energy Louisiana, LLC		Delaware

HRC Energy Resources (LaFourche), Inc.		Louisiana

HRC Energy Resources (WV), Inc.		Delaware

Halcón GEO Holdings, LLC		Delaware

Pontotoc Production Company, Inc.		Texas

AROC (Texas), Inc.		Texas

Catena Oil & Gas LLC		Texas

G3 Energy, LLC		Colorado

G3 Operating, LLC		Colorado

Southern Bay Operating, L.L.C.		Texas

Southern Bay Energy, LLC		Texas

Southern Bay Louisiana, LLC		Texas

Western Star Drilling Company		North Dakota

Exhibit A

LOCK-UP LETTER AGREEMENT

BARCLAYS CAPITAL INC.

GOLDMAN, SACHS & CO.

J.P. MORGAN SECURITIES LLC

As Representatives of the several

Underwriters named in Schedule 1 attached hereto

c/o Barclays Capital Inc.

745 Seventh Avenue

New York, New York 10019

Ladies and Gentlemen:

The undersigned understands that you and certain other firms (the “Underwriters”) propose to enter into an Underwriting Agreement (the “Underwriting Agreement”) providing for the purchase by the Underwriters of shares (the “Stock”) of Common Stock, par value $0.0001 per share (the “Common Stock”), of Halcón Resources Corporation, a Delaware corporation (the “Company”), and that the Underwriters propose to reoffer the Stock to the public (the “Offering”).

In consideration of the execution of the Underwriting Agreement by the Underwriters, and for other good and valuable consideration, the undersigned hereby irrevocably agrees that, without the prior written consent of Barclays Capital Inc., on behalf of the Underwriters, the undersigned will not, directly or indirectly, (1) offer for sale, sell, pledge, or otherwise dispose of (or enter into any transaction or device that is designed to, or could be expected to, result in the disposition by any person at any time in the future of) any shares of Common Stock (including, without limitation, shares of Common Stock that may be deemed to be beneficially owned by the undersigned in accordance with the rules and regulations of the Securities and Exchange Commission and shares of Common Stock that may be issued upon exercise of any options or warrants) or securities convertible into or exercisable or exchangeable for Common Stock, (2) enter into any swap or other derivatives transaction that transfers to another, in whole or in part, any of the economic benefits or risks of ownership of shares of Common Stock, whether any such transaction described in clause (1) or (2) above is to be settled by delivery of Common Stock or other securities, in cash or otherwise, (3) make any demand for or exercise any right or cause to be filed a registration statement, including any amendments thereto, with respect to the registration of any shares of Common Stock or securities convertible into or exercisable or exchangeable for Common Stock or any other securities of the Company or (4) publicly disclose the intention to do any of the foregoing, for a period commencing on the date hereof and ending on the 90th day after the date of the Prospectus relating to the Offering (such 90-day period, the “Lock-Up Period”).

The undersigned hereby further agrees that, prior to engaging in any transaction or taking any other action that is subject to the terms of this Lock-Up Letter Agreement during the period from the date of this Lock-Up Letter Agreement to and including the 34^th day following the expiration of the Lock-Up Period, it will give notice thereof to the Company and will not consummate such transaction or take any such action unless it has received written confirmation from the Company that the Lock-Up Period (as such may have been extended pursuant to this paragraph) has expired.

In furtherance of the foregoing, the Company and its transfer agent are hereby authorized to decline to make any transfer of securities if such transfer would constitute a violation or breach of this Lock-Up Letter Agreement.

It is understood that, if the Company notifies the Underwriters that it does not intend to proceed with the Offering, if the Underwriting Agreement does not become effective, or if the Underwriting Agreement (other than the provisions thereof which survive termination) shall terminate or be terminated prior to payment for and delivery of the Stock, the undersigned will be released from its obligations under this Lock-Up Letter Agreement.

The undersigned understands that the Company and the Underwriters will proceed with the Offering in reliance on this Lock-Up Letter Agreement.

Whether or not the Offering actually occurs depends on a number of factors, including market conditions. Any Offering will only be made pursuant to an Underwriting Agreement, the terms of which are subject to negotiation between the Company and the Underwriters.

[Signature page follows]

The undersigned hereby represents and warrants that the undersigned has full power and authority to enter into this Lock-Up Letter Agreement and that, upon request, the undersigned will execute any additional documents necessary in connection with the enforcement hereof. Any obligations of the undersigned shall be binding upon the heirs, personal representatives, successors and assigns of the undersigned.

Dated:

EXHIBIT B-1

FORM OF OPINION OF ISSUER’S COUNSEL

1.(a) Each Halcón Corporation is a corporation validly existing and in good standing under the laws of the state of its incorporation.

(b) Each Halcón LLC is a limited liability company validly existing and in good standing under the laws of the state of its formation.

(c) The Halcón Partnership is a limited partnership validly existing and in good standing under the laws of the State of Texas.

2. Based solely on certificates of public officials, each Relevant Party was duly qualified or licensed to do business and is in good standing as a foreign corporation in each jurisdiction listed in Schedule I.B with respect to it as of the respective dates specified in such Schedule.

3.(a) Each of each Halcón Corporation, each Halcón LLC and the Halcón Partnership has the corporate, limited liability company or partnership power and authority, as applicable, to carry on its business and to own, lease and operate its properties and assets, in each case as described in the Preliminary Prospectus, and, in the case of the Company, to execute, deliver and perform the Underwriting Agreement.

(b) The Company has taken all corporate action necessary to authorize the execution, delivery and performance of the Underwriting Agreement, and has duly executed and delivered the Underwriting Agreement.

4. The execution and delivery by the Company of the Underwriting Agreement do not, and the performance by it of its obligations under the Underwriting Agreement will not:

(a) violate its certificate of incorporation or bylaws;

(b) breach or result in a default or the creation of any lien under any agreement or instrument listed in Schedule I.C (the “Applicable Contracts”) or any order, writ, judgment, injunction, decree, determination or award listed in Schedule I.D; or

(c) result in a violation by the Company of any Applicable Laws, the Delaware General Corporation Law, the Securities Act of 1933, as amended (the “Securities Act”) or the Securities Exchange Act of 1934, as amended (the “Exchange Act”).

5. No authorization, approval or other action by, and no notice to or filing with, any United States federal or New York governmental authority or regulatory body, or any third party that is a party to an Applicable Contract, is required under Applicable Laws, the Securities Act or the Exchange Act for the due execution, delivery or performance by a Relevant Party of the Underwriting Agreement or the consummation by the Company of the transactions contemplated thereby.

6. The Company is not, and as a result of the transactions contemplated by the Underwriting Agreement will not be, required to register as an investment company under the Investment Company Act.

7. The statements set forth under the heading “Description of Capital Stock” in the Pricing Disclosure Package and the Prospectus insofar as such statements purport to summarize the terms of the Common Stock (including the Shares), accurately summarize such documents in all material respects.

8. The statements set forth under the headings “Description of Capital Stock”, “Certain ERISA Considerations” and “Certain United States Federal Income Tax Consequences to Non-United States Holders”, in the Preliminary Prospectus and the Prospectus, in each case insofar as such statements purport to constitute summaries of the terms of statutes, rules, regulations or documents, accurately summarize such statutes, rules, regulations and documents in all material respects.

9.(a) The authorized capital stock of the Company is as set forth in the Preliminary Prospectus and the Prospectus.

(b) The shares of capital stock of the Company that have been issued on or after February 8, 2012 (including the Shares) and are listed on Schedule I.F hereto have been duly authorized and validly issued, are fully paid and non-assessable, conform to the description thereof contained the Preliminary Prospectus and Prospectus.

(c) The issuance of such capital stock was not subject to preemptive rights under the Delaware General Corporation Law, the certificate of incorporation or by-laws of the Company or any Applicable Contract.

(d) No Applicable Contract requires any securities of the Company owned or to be owned by any person to be included in the securities registered pursuant to the Registration Statement.

10. We are not representing any Relevant Party in any pending litigation in which it is a named defendant that challenges the validity or enforceability of, or seeks to enjoin the performance of, the Underwriting Agreement.

11. The Registration Statement became effective under the Securities Act as of the date it was filed with the SEC, and the Preliminary Prospectus was filed with the SEC pursuant to pursuant to Rule 424(b)(5) on September , 2012. Based solely on a telephone call approximately at : .m. today with a representative of the SEC, no stop order suspending the effectiveness of the Registration Statement has been issued and, no proceedings for that purpose have been instituted by the SEC.

12. The Registration Statement, as of its effective date, the Pricing Disclosure Package, as of its date and the Applicable Time, and the Prospectus as of its date and the date hereof, complied and comply as to form in all material respects with the requirements of Form S-3 under the Securities Act of 1933, as amended, and the rules and regulations promulgated thereunder.

Such counsel shall also furnish to the Underwriters a written statement, addressed to the Underwriters and dated the Closing Date, in form and substance satisfactory to the Underwriters, to the effect that such counsel reviewed the Registration Statement, the Pricing Disclosure Package and the Prospectus and participated in conferences with officers and other representatives of the Company, representatives of the Underwriters and counsel for the Underwriters, and representatives of the independent public accountants and independent reserve engineers for the Company, GeoResources and the East Texas Assets, at which the contents of the Registration Statement, the Pricing Disclosure Package and the Prospectus and related matters were discussed. The purpose of such counsel’s professional engagement was not to establish or confirm factual matters set forth in the Registration Statement, the Pricing Disclosure Package or the Prospectus, and such counsel has not undertaken to verify independently any of such factual matters. Moreover, many of the determinations required to be made in the preparation of the Registration Statement, the Pricing Disclosure Package and the Prospectus involve matters of a non-legal nature. Subject to the foregoing, such counsel confirms to you that, on the basis of the information such counsel gained in the course of performing the services referred to above, nothing came to the attention of such counsel that caused it to believe that:

(a) the Registration Statement, as of its most recent effective date, contained an untrue statement of a material fact or omitted to state a material fact required to be stated therein or necessary to make the statements therein not misleading;

(b) the Pricing Disclosure Package, as of 5:00 p.m. Eastern time on September 12, 2012 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 the circumstances under which they were made, not misleading, or

(c) the Prospectus, as of its date and as of the date this opinion, contained or contains any untrue statement of a material fact or omitted or omits 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;

provided that such counsel does not assume any responsibility for the accuracy, completeness or fairness of the statements contained in the Registration Statement, the Pricing Disclosure Package or the Prospectus (except as otherwise specifically stated in paragraphs 14, 15 and 16), and such counsel does not express any belief with respect to the financial statements and related notes and schedules and other financial data, or oil and gas reserves or prospects, production data or related geological data, or related statistical data derived from such financial, oil and gas reserves, prospects, production data or geological data, contained in or omitted from the Registration Statement, the Pricing Disclosure Package and the Prospectus.

Exhibit B-2

FORM OF GENERAL COUNSEL’S OPINION

1. To my knowledge, all of the issued shares of capital stock or other equity interests of each Subsidiary have been duly authorized and validly issued, are fully paid and non-assessable and are owned directly or indirectly by the Company, free and clear of all liens, encumbrances, equities or claims, except for such liens, encumbrances, equities or claims (i) as described in the Prospectus and the Preliminary Prospectus or (ii) as could not, in the aggregate, reasonably be expected to have a Material Adverse Effect (as defined in the Underwriting Agreement).

2. To my knowledge, there are no legal or governmental 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 that could reasonably be expected to have a Material Adverse Effect or could reasonably be expected to have a Material Adverse Effect on the Company’s performance of the Underwriting Agreement or the consummation by the Company of the transactions contemplated therein.

EXHIBIT B-3

FORM OF OPINION OF SELLING STOCKHOLDER’S COUNSEL

1. The Selling Stockholder is a limited partnership that is validly existing and in good standing under laws of the State of Texas.

2. The Selling Stockholder has:

(a) the limited partnership power to execute, deliver and perform the Underwriting Agreement;

(b) taken all limited partnership action necessary to authorize the execution, delivery and performance of the Underwriting Agreement; and

3. The execution and delivery by the Selling Stockholder of the Underwriting Agreement do not, and the performance by the Selling Stockholder of its obligations thereunder will not:

(a) violate its certificate of formation or limited partnership agreement;

(b) breach or result in a default or the creation of any lien under any agreement or instrument listed in Schedule I.B hereto (the “Applicable Contracts”) (except that we express no opinion with respect to financial covenants and other similar provisions in any Applicable Contract requiring financial calculations or determinations to ascertain compliance) or any order, writ, judgment, injunction, decree, determination or award listed in Schedule I.C hereto; or

4. No authorization, approval or other action by, and no notice to or filing with, any United States federal or Texas or New York governmental authority or regulatory body, or any third party that is a party to any Applicable Contract, is required under Applicable Laws for the due execution, delivery or performance by the Selling Stockholder of the Underwriting Agreement, except that we express no opinion with respect to authorizations, approvals, actions, notices and filings that may be required in connection with financial covenants and other similar provisions in any Applicable Contract requiring financial calculations or determinations to ascertain compliance.

5. Based solely on a review of the stock register of the Company, as of the date hereof and prior to the consummation of the transactions contemplated by the Underwriting Agreement, the Selling Stockholder is listed in such stock register as the holder of record of shares of Common Stock.

6. Each Underwriter has acquired a security entitlement with respect to the Shares credited to its Securities Account, and no action based on an adverse claim to the Shares may be asserted against the Underwriter acquiring such security entitlement with respect to such Shares.