FIRST AMENDMENT TO ASSET PURCHASE AGREEMENT

Exhibit 10.1

Execution Copy

FIRST AMENDMENT
TO ASSET PURCHASE AGREEMENT

     This First Amendment to Asset Purchase Agreement (the “ Amendment ”) is entered into as of the 18th day of November, 2008 by and among Superior Well Services, Inc., a Delaware corporation (the “ Parent ”), Superior Well Services, Ltd. , a Pennsylvania limited partnership and an indirect wholly owned subsidiary of Parent (the “ Buyer ”), Diamondback Holdings, LLC, a Delaware limited liability company (“ Diamondback ”), Diamondback-Total Services LLC, an Oklahoma limited liability company (“ Diamondback Total Services ”), Diamondback Pumping GP LLC, an Oklahoma limited liability company (“ Diamondback Pumping GP ”), Diamondback Pumping Service LLC, an Oklahoma limited liability company (“ Diamondback Pumping Services ”), Diamondback-Pioneer LLC, an Oklahoma limited liability company (“ Diamondback Pioneer ”), Packers & Service Tools, Inc., a Louisiana corporation (“ P&S Tools ”), Diamondback-Total Pumping GP LLC, an Oklahoma limited liability company (“ Diamondback Total Pumping ”), Diamondback-Total Texas LLC, an Oklahoma limited liability company (“ Diamondback-Total Texas ”), Diamondback-Disposal Texas LLC, an Oklahoma limited liability company (“ Diamondback Disposal Texas ”), Diamondback-TD West LLC, a Texas limited liability company (“ Diamondback-TD West ”), Diamondback-Disposal LLC, an Oklahoma limited liability company (“ Diamondback Disposal ”), Diamondback-Total Oklahoma LLC, a Delaware limited liability company (“ Diamondback-Total Oklahoma ”), Sooner Trucking & Oilfield Services, Inc., an Oklahoma corporation (“ Sooner ”), Diamondback-PST LLC, an Oklahoma limited liability company (“ Diamondback PST ”), Diamondback-Completions LLC, an Oklahoma limited liability company (“ Diamondback Completions ”), and TD West LLC, a Texas limited liability company (“ TD West ” and each of Diamondback Total Services, Diamondback Pumping GP, Diamondback Pumping Service, Diamondback Pioneer, P&S Tools, Diamondback Total Pumping, Diamondback-Total Texas, Diamondback-Disposal Texas, Diamondback-TD West, Diamondback Disposal, Diamondback-Total Oklahoma, Sooner, Diamondback PST and Diamondback Completions being a “ Diamondback Subsidiary ” and, collectively, the “ Diamondback Subsidiaries ”)) and Diamondback Downhole Technologies LLC ( “Downhole Technologies” ), Diamondback-Directional Drilling LLC ( “Directional Drilling Contractors” ) and Diamondback-Quantum LLC ( “Quantum” and along with Downhole Technologies and Directional Drilling Contractors the “Drilling Companies” ). The Buyer and Parent are sometimes referred to individually as a “ Buyer Party ” and collectively as the “ Buyer Parties .” Diamondback, the Drilling Companies and the Diamondback Subsidiaries are sometimes referred to individually as a “ Seller ” or a “ Seller Party ” and collectively as the “ Sellers ” or the “ Seller Parties ” as follows:

     WHEREAS, the Buyer Parties and Seller Parties have heretofore entered into that certain Asset Purchase Agreement dated September 12, 2008 (the “ Purchase Agreement ”) providing for the purchase by Buyer of certain assets comprising Diamondback’s stimulation and pumping services segment, completion and production services segment and fluid logistics and well-site services segment;

     WHEREAS, the Buyer Parties and Sellers Parties desire to enter into an amendment to reflect certain mutually agreed revisions to the Purchase Agreement;

     NOW, THEREFORE, in consideration of the provisions, agreements and covenants contained herein; and other good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged and in reliance upon the material representations and warranties contained herein, the parties hereto agree as follows:

ARTICLE I
DEFINED TERMS

      1.1 Defined Terms . All capitalized terms which are used but not defined in this Amendment shall have meanings assigned to such terms in the Purchase Agreement.

ARTICLE II
AMENDMENTS TO THE PURCHASE AGREEMENT

      2.1 The Purchase Agreement is hereby amended as follows:

(a) Section 2.2 of the Purchase Agreement is hereby revised and amended in its entirety to read as follows:

      “2.2 Purchase Price .

     (a) The total consideration (the “ Purchase Price ”) to be paid by the Buyer to the Sellers for the sale, transfer, assignment, conveyance and delivery of the Purchased Assets shall be (i) the assumption of the Assumed Obligations, (ii) the payment (by wire transfer at Closing) of Seventy Million Dollars ($70,000,000) of immediately available cash funds (the “ Cash Payment ”) in accordance with the wire transfer instructions set forth on Schedule 2.2(a) , subject to adjustment pursuant to Sections 2.2(b), 3.2 and 6.4(b), (iii) delivery to Sellers of Second Lien Notes in the original, aggregate principal amount of Eighty Million Dollars ($80,000,000) and (iv) delivery to Sellers of 75,000 shares of Convertible Preferred Stock with a liquidation value (based on a liquidation value of $1000 per share) of Seventy Five Million Dollars ($75,000,000) as reflected on Schedule 2.2(a) , which includes 60,000 shares of Convertible Preferred Stock being delivered directly to Sellers and 15,000 shares of Convertible Preferred Stock being deposited into escrow pursuant to Section 2.6 below.

     (b) The Cash Payment portion of the Purchase Price payable at Closing will be $69,695,304 which reflects (i) an increase of $901,745 for deposits/prepayments which are being purchased by Buyer from Sellers at Closing and (ii) a decrease of $1,130,896 which is the Estimated Accrued PTO amount and (iii) a decrease of $75,545 which is the agreed amount for that certain 2007 Mack Truck (#06392) which was damaged in an accident on or about November 9, 2008, which truck will be excluded from the Purchased Assets and retained by Sellers, such adjustment amounts being reflected in more detail on Schedule 2.2(b) .

(b) Section 2.6 of the Purchase Agreement is hereby revised in its entirety to read as follows:

      “2.6 Escrow . At the Closing, 15,000 shares of Convertible Preferred Stock with a liquidation value (based on a liquidation value of $1000 per share) of Fifteen Million Dollars ($15,000,000) of the Purchase Price (the “ Escrow Amount ”) (along with blank stock powers or letters of assignment executed by the applicable Sellers) shall be delivered by the Buyer to the Escrow Agent to be held in escrow under the terms of the Escrow Agreement attached as Exhibit 2.6 (the “ Escrow Agreement ”). The Escrow Agreement and the shares of Convertible Preferred Stock held therein shall be held by the Escrow Agent pursuant to and distributed to the Buyer or the Sellers Representative, as the case may be, in accordance with the terms of the Escrow Agreement.”

(c) Section 3.1 of the Purchase Agreement is hereby revised in its entirety to read as follows:

      “3.1 Inventory Adjustment.

     (a) Inventory Procedures . The parties hereto acknowledge that the Purchase Price has been based in part on the Purchased Assets including Inventory as of the Effective Time which is adequate for the operation of the Business in the Ordinary Course of Business and which has a value of at least Ten Million Dollars ($10,000,000.00) (the “ Inventory Threshold ”). For purposes of determining the value of the Inventory as of the Effective Time (the “ Inventory Value ”), the Inventory included in the Purchased Assets shall be measured and valued as of the Effective Time in accordance with the following inventory determination and valuation procedures:

     (i) On a date which is prior to the scheduled Closing Date and is mutually agreed between Buyer and the Seller’s Representative, representatives of the Buyer and Sellers shall jointly conduct a physical count of the Inventory, such physical count to be brought forward and adjusted through the close of business immediately prior to the Effective Time, using the inventory counting and recognition methodologies and practices set forth in Schedule 3.1(a)(i) (“ Inventory Count ”). The Sellers acknowledge that Buyer may have Schneider Downs observe the inventory process at Buyer’s expense. In connection with the calculation of the Inventory Value, the Buyer and its representatives, if requested by the Buyer, will have reasonable access to all requisite accounting and other records of Sellers, if necessary. The parties will use their respective Reasonable Efforts to complete the Inventory Count promptly and, in any event, prior to or within three days after the Closing. If the parties cannot agree on the Inventory Value based upon the Inventory Count within twenty (20) days after the Closing, the parties shall submit such matter to a mutually agreed upon third party for review and resolution, with the fees and expenses thereof to be borne 50% by the Sellers and 50% by the

Buyer, and any determination by such third party shall be final and binding upon the Parties.

     (ii) Within three (3) Business Days following the final determination of the Inventory Value (whether by agreement or third party appraisal) the Buyer Parties or the Sellers, as the case may be, shall pay by wire transfer to the other Party immediately available U.S. funds in an amount equal to the excess (in the case of the Buyer Parties) or shortfall (in the case of the Sellers) of the Inventory Value as compared to the Inventory Threshold, if any. If not paid when due, interest shall accrue on the amount due at a rate equal to the lesser of (a) 10% per annum or (b) the maximum rate permitted by applicable law.

     (iii) Inventory included in the Inventory Threshold shall be determined in a manner consistent with the presentation of Inventory on the 2007 Annual Financial Statements.”

(d) Article IV of the Purchase Agreement is revised and amended to include a new Section 4.28 which reads as follows:

      “4.28 Securities Representations

     (a) Each Seller is acquiring the Second Lien Notes and Convertible Preferred Stock (the “ Buyer Securities ”) for such Seller’s own account and not with a view to, or for offer of resale in connection with, a distribution thereof, within the meaning of the Securities Act. In acquiring the Buyer Securities, such Seller is not offering or selling, and will not offer or sell, for itself in connection with any distribution of the Buyer Securities, and such Seller does not have a participation in and will not participate in any such undertaking or in any underwriting of such an undertaking except in compliance with applicable federal and state securities laws.

     (b) Each Seller is an “accredited investor” as such term is defined under Regulation D promulgated under the Securities Act. Each Seller acknowledges that the Seller can bear the economic risk of the Seller’s investment in the Buyer Securities, and has such knowledge and experience in financial and business matters similar to the transaction described herein such that the Seller is capable of evaluating the merits and risks of an investment in the Buyer Securities.

     (c) Each Seller understands that such Buyer Securities have not been registered pursuant to the Securities Act or any applicable state securities laws, that the Buyer Securities, when issued, will be characterized as “restricted securities” under federal securities laws, and that under such laws and applicable regulations the Buyer Securities cannot be sold or otherwise disposed of without registration under the Securities Act or an exemption therefrom. Each Seller represents that such Seller is familiar with Rule 144 promulgated under the

Securities Act, as currently in effect, and understands the resale limitations imposed thereby and by the Securities Act and that, should any certificate be issued representing any of the Buyer Securities, each such certificate shall conspicuously set forth on the face or back thereof, in addition to any legends required by Law or other agreement, a legend to the effect set forth in Section 6.24.

     (d) Each Seller represents and acknowledges that Buyer is issuing the Buyer Securities pursuant to an exemption from the registration requirements of the Securities Act based on the representations provided by Sellers hereunder.

     (e) Each Seller has received or has had full access to all the information it considers necessary or appropriate to make an informed investment decision with respect to the Buyer Securities to be acquired by such Purchaser under this Agreement. Such Seller further has had an opportunity to ask questions and receive answers from the Parent regarding the terms and conditions of the issuance of the Buyer Securities and to obtain additional information (to the extent the Parent possessed such information or could acquire it without unreasonable effort or expense) necessary to verify any information furnished to such Seller or to which such Seller had access. The foregoing, however, does not in any way limit or modify the representations and warranties made by the Buyer Parties in Article V of this Agreement. Sellers acknowledge that, except as specifically provided in this Agreement, the Parent and Buyer make no representations or warranties, express or implied, as to the condition (financial or otherwise), assets, liabilities, operations, business or prospects of Buyer or the Parent.”

(e) Article V of the Purchase Agreement is revised and amended to include the following new sections 5.8, 5.9 and 5.10 which read as follows:

      “5.8 Authorization of Convertible Preferred Stock .

     (a) Parent has all requisite corporate power and authority to issue to Sellers and sell the Convertible Preferred Stock and the Parent Common Stock issuable upon conversion thereof. All corporate action on the part of the Parent necessary for the authorization, issuance (or reservation for issuance), sale, and delivery of the Convertible Preferred Stock in accordance with the Certificate of Designation and the Parent Common Stock issuable upon conversion thereof has been taken. The sale and issuance of the Convertible Preferred Stock is not, and the subsequent conversion of the Convertible Preferred Stock into Parent Common Stock will not be, subject to any preemptive rights or rights of first refusal.

     (b) The Convertible Preferred Stock, when issued, sold, and delivered in accordance with the terms of this Agreement and the Certificate of Designation for the consideration expressed herein, will be duly and validly issued, fully paid, and nonassessable, and will be free of all Liens and restrictions imposed by or

through the Parent other than restrictions as set forth in Sections 2.6 and 6.24 of this Agreement in the Registration Rights Agreement and under applicable state and federal securities laws. The Parent Common Stock issuable upon conversion of the Convertible Preferred Stock has been duly and validly reserved for issuance and, upon issuance, will be duly and validly issued, fully paid, and nonassessable and will be free of all Liens and restrictions imposed by or through the Parent other than restrictions set forth in Sections 2.6 and 6.24 of this Agreement, in the Registration Rights Agreement and under applicable state and federal securities laws.

     (c) No consent, approval, order or authorization of, or registration, qualification, designation, declaration or filing with, any Governmental Authority or any Person is required on the part of the Parent in connection with the issuance, sale and delivery of the Convertible Preferred Stock, or the issuance of Parent Common Stock upon conversion of the Convertible Preferred Stock, except such filings as have been made prior to the Closing and except for post-closing notice filings, if any, as may be required under applicable federal and state securities laws and which, if required, will be made by Parent.

      5.9 Authorization of Second Lien Notes .

     (a) Parent has all requisite corporate power and authority to issue and sell to Sellers the Second Lien Notes. All corporate action on the part of Parent necessary for the authorization, issuance, sale and delivery of the Second Lien Notes has been taken.

     (b) No consent, approval, order or authorization of, or registration, qualification, designation, declaration or filing with, any Governmental Authority or any Person is required on the part of the Company in connection with the issuance, sale and delivery of the Second Lien Notes, except such filings as have been made prior to the Closing and except for any post-closing filings as may be required under applicable federal and state securities laws.

      5.10 Additional Representations Regarding the Parent .

     (a) SEC Reports; Capitalization . (i) Parent has filed all required reports, schedules, forms, statements and other documents required to be filed with the SEC (collectively, including all exhibits and schedules thereto, the “ Parent SEC Reports ”). None of the Parent SEC Reports, as of the respective dates (and, if amended or superseded by other filings, then on the date of such filing), contained any 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, in light of the circumstances under which they were made, not misleading. Each of the financial statements (including the related notes) included within the Parent SEC Reports presents fairly, in all material respects, the consolidated financial position and consolidated results of operations and cash

flows of Parent as of the respective dates or for the respective periods set forth therein, all in accordance with GAAP consistently applied during the periods involved except otherwise noted therein.

     (b) The authorized capitalization of Parent consists of 70,000,000 shares of common stock, par value $.01 per share, and 10,000,000 shares of preferred stock issuable in series. Immediately prior to the Closing Date, there are no shares of preferred stock of the Parent issued and outstanding. Except as disclosed in the Parent SEC Reports, there are no (A) outstanding securities of Parent convertible into, exchangeable or exercisable for equity interests or other securities of Parent, (B) authorized or outstanding options, warrants or other rights to purchase or acquire from Parent, or obligations of Parent to issue, any equity interests or other securities, including securities convertible into or exchangeable for common stock or other securities of Parent, or (C) authorized or outstanding bonds, debentures, notes or other indebtedness that entitles the holders to vote (or convertible or exercisable for or exchangeable into securities that entitle the holders to vote) with holders of common stock of Parent on any matter.

     (c) Litigation . Except as described in the Parent SEC Reports, there are no actions, suits, proceedings or investigations pending or, to the knowledge of the Parent, threatened against Parent or any Subsidiary of Parent at law or in equity before any Governmental Authority which individually or in the aggregate may result in any Parent Material Adverse Change. None of the Parent or any Subsidiaries of the Parent is in violation of any order, writ, injunction or any decree of any Governmental Authority which would be reasonably expected to result in any Parent Material Adverse Change.

     (d) Taxes . All federal, state, local and other tax returns required to have been filed with respect to the Parent and each Subsidiary of Parent have been filed, and payment or adequate provision has been made for the payment of all material taxes, fees, assessments and other governmental charges which have or may become due pursuant to said returns or to assessments received, except to the extent that such taxes, fees, assessments and other charges are being contested in good faith by appropriate proceedings diligently conducted and for which such reserves or other appropriate provisions, if any, as shall be required by GAAP shall have been made and except as would not be reasonably likely to result in a Parent Material Adverse Effect.

     (e) Patents, Trademarks, Copyrights, Licenses, Etc . The Parent and each Subsidiary of Parent owns or possesses all the material patents, trademarks, service marks, trade names, copyrights, licenses, registrations, franchises, permits and rights necessary to own and operate its properties and to carry on its business as presently conducted and planned to be conducted by such Parent, such Buyer Party or Subsidiary, without known possible, alleged or actual conflict with the

rights of others, except for any such failure which would not be reasonably likely to result in a Parent Material Adverse Effect.

     (f) Second Liens in the Collateral . The second liens granted to the Sellers pursuant to the Second Lien Security Agreement constitute validly perfected second priority Liens.

     (g) Insurance . The properties of the Parent and each of its Subsidiaries are insured pursuant to insurance policies and other bonds which are valid and in full force and effect and which provide coverage from reputable insurers in amounts which Parent believes are sufficient to insure the assets and risks of the Parent and each of its Subsidiaries in accordance with prudent business practice in the industry of Parent and its Subsidiaries.

     (h) ERISA Compliance .

     (i) Each Parent Plan is in compliance in all material respects with the applicable provisions of ERISA, the Code and other federal or state laws. Each Parent Plan that is intended to qualify under Section 401(a) of the Code has received a favorable determination letter from the IRS or an application for such a letter is currently being processed by the IRS with respect thereto and, to the knowledge of Parent, nothing has occurred which would prevent, or cause the loss of, such qualification. Parent and its Subsidiaries have made all required contributions to each Parent Plan subject to Section 412 of the Code, and no application for a funding waiver or an extension of any amortization period pursuant to Section 412 of the Code has been made with respect to any Parent Plan.

     (ii) (A) neither Parent nor any Subsidiary has incurred, or reasonably expects to incur, any liability under Title IV of ERISA with respect to any Buyer Plan which is a pension plan (other than premiums due and not delinquent under Section 4007 of ERISA); (B) neither Parent nor any Subsidiary has incurred, or reasonably expects to incur, any liability (and no event has occurred which, with the giving of notice under Section 4219 of ERISA, would result in such liability) under Sections 4201 or 4243 of ERISA with respect to a multiemployer plan; and (C) neither Parent nor any Subsidiary has engaged in a transaction that could be subject to Sections 4069 or 4212(c) of ERISA.

     (i) Solvency . The Parent is Solvent. After giving effect to the transactions contemplated by this Agreement, including all indebtedness incurred thereby, the Liens granted by the Parent in connection therewith and the payment of all fees related thereto, the Parent will be Solvent, determined as of the Closing