Exhibit 10.31

EXECUTION

MASTER ASSIGNMENT AND ASSUMPTION

This Master Assignment and Assumption (the “Master Assignment and Assumption”)
is dated as of December 20, 2012 (the “Effective Date”), and is entered into by
and between the Assignors (as defined below) and the Assignees (as defined
below). Capitalized terms used but not defined herein shall have the meanings
given to them in the Existing Credit Agreement or the Amended and Restated
Credit Agreement identified below. The Standard Terms and Conditions set forth
in Annex I attached hereto (the “Standard Terms and Conditions”) are hereby
agreed to and incorporated herein by reference and made a part of this Master
Assignment and Assumption as if set forth herein in full.

R E C I T A L S:

1. Reference is made to that certain Second Amended and Restated Credit
Agreement, dated as of September 21, 2010 among PostRock Energy Services
Corporation, a Delaware corporation, and PostRock MidContinent Production, LLC,
a Delaware limited liability company (collectively, the “Borrowers”), the
lenders party thereto (the “Existing Lenders”), Royal Bank of Canada, as
administrative agent and collateral agent (the “Existing Administrative Agent”),
as amended by a First Amendment dated May 31, 2012 but effective as of June 1,
2012 and a Second Amendment dated July 20, 2012 (as amended by such First
Amendment and Second Amendment, the “Existing Credit Agreement”).

2. As of the Effective Date, the Existing Credit Agreement is being amended and
restated in its entirety (as amended and restated, the “Amended and Restated
Credit Agreement”), the commitments thereunder are being reduced from
$98,000,000 to $90,000,000, and Citibank, N.A. (the “Successor Administrative
Agent”) will succeed Royal Bank of Canada as administrative agent and collateral
agent and Citibank, N.A. will become the letter of credit issuer. Each of the
Assignees (hereinafter defined) hereby acknowledges receipt of a copy of the
Amended and Restated Credit Agreement.

AGREEMENT

(A) For agreed consideration, as of the Effective Date, each Existing Lender set
forth on Annex II hereto (each individually an “Assignor” and collectively, the
“Assignors”) hereby irrevocably sells and assigns at par (i.e., outstanding
principal, accrued unpaid interest, fees and all other amounts owing to such
Existing Lender as of the Effective Date), severally and not jointly, to the
persons indicated on Annex II hereto (each individually an “Assignee” and
collectively, the “Assignees”), and each Assignee, severally and not jointly,
subject to and in accordance with the Standard Terms and Conditions and the
Existing Credit Agreement hereby irrevocably purchases and assumes from the
Assignors such Assignee’s Pro Rata Share (hereinafter defined) of the aggregate
Assigned Interests (hereinafter defined) of such Assignors as provided on Annex
II: (i) each such Assignor’s rights and obligations in its capacity as an
Existing Lender under the Existing Credit Agreement and any other documents or
instruments delivered pursuant thereto with respect to such Assignor’s interests
set forth on Annex II hereto, and (ii) to the extent permitted to be assigned
under applicable Law, all claims, suits, causes of action and any other right of
such Assignor (in its capacity as an Existing Lender) against any Person,
whether known or unknown, arising under or in connection with the Existing
Credit Agreement, any other documents or instruments delivered pursuant thereto
or the loan transactions governed thereby or in any way based on or related to
any of the foregoing including, but not limited to, contract claims, tort
claims, malpractice claims, statutory claims and all other claims at law or in
equity related to the rights and obligations sold and assigned pursuant to
clause (i) above (the rights and obligations sold and assigned pursuant to
clauses (i) and (ii) being referred to herein collectively for all Assignors as
the “Assigned Interests”),

Master Assignment and Assumption

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subject to and in accordance with this Master Assignment and Assumption. “Pro
Rata Share” means, at any date of determination, for any Assignee, the
percentage (carried out to the ninth decimal place) that its Revolving
Commitment with respect to the Revolving Loans that such Assignee purchases of
the Assigned Interests (as set forth in Annex II) bears to the aggregate
Assigned Interests purchased by all Assignees pursuant to this Master Assignment
and Assumption. Such sale and assignment is without recourse to the Assignors
and, except as expressly provided in this Master Assignment and Assumption,
without representation or warranty by the Assignors.

The Existing Lenders hereby agree that their execution hereof constitutes an
amendment to the Existing Credit Agreement and that this Master Assignment and
Assumption is an Assignment and Assumption (as defined in the Existing Credit
Agreement). This Master Assignment and Assumption is a “Loan Document” as
defined in the Existing Credit Agreement.

(REMAINDER OF PAGE INTENTIONALLY LEFT BLANK.)

 

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ASSIGNORS:

ROYAL BANK OF CANADA,

as an Assignor

By:   /s/ Leslie P. Vowell Name:   Leslie P. Vowell Title:   Attorney-in-Fact

 

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ASSIGNORS:

KEY BANK NATIONAL ASSOCIATION,

as an Assignor

By:   /s/ Carla Laning Name:   Carla Laning Title:   Senior Vice President

 

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ASSIGNORS:

WELLS FARGO BANK, NATIONAL ASSOCIATION,

as an Assignor

By:   /s/ Ronald F. Bentien, Jr. Name:   Ronald F. Bentien, Jr. Title:   Senior
Vice President

 

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ASSIGNORS:

AMEGY BANK NATIONAL ASSOCIATION,

as an Assignor

By:   /s/ Terry O. McCarter Name:   Terry O. McCarter Title:   Senior Vice
President

 

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ASSIGNORS:

SOCIÉTÉ GÉNÉRALE,

as an Assignor

By:   /s/ David M. Bornstein Name:   David M. Bornstein Title:   Director

 

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ASSIGNORS:

U.S. BANK NATIONAL ASSOCIATION,

as an Assignor

By:   /s/ Saqib Khawaja Name:   Saqib Khawaja Title:   Vice President

 

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ASSIGNORS:

COMERICA BANK,

as an Assignor

By:   /s/ David P. Cagle Name:   David P. Cagle Title:   Senior Vice President

 

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ASSIGNORS:

RB INTERNATIONAL FINANCE (USA) LLC,

f/k/a RZB Finance, LLC, as an Assignor

By:   /s/ Stephen A. Plauche Name:   Stephen A. Plauche Title:   First Vice
President By:   /s/ Brad Woodhouse Name:   Brad Woodhouse Title:   Vice
President

 

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ASSIGNORS:

BOKF, NA, d/b/a BANK OF OKLAHOMA,

as an Assignor

By:   /s/ Mike Weatherholt Name:   Mike Weatherholt Title:   Vice President

 

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ASSIGNORS:

CITIBANK, N.A.,

as an Assignor

By:   /s/ John Peruzzi Name:   John Peruzzi Title:   Vice President

 

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ASSIGNORS:

COMPASS BANK, N.A.,

as an Assignor

By:   /s/ Ian Payne Name:   Ian Payne Title:   Vice President

 

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ASSIGNORS:

NZC GUGGENHEIM MASTER FUND LTD.,

as an Assignor

By:   Guggenheim Partners Investment Management, LLC, as Manager By:   /s/
William R. Hagner Name:   William R. Hagner Title:   Senior Managing Director

 

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ASSIGNORS:

SUNTRUST BANK,

as an Assignor

By:   /s/ Janet R. Naifeh Name:   Janet R. Naifeh Title:   Senior Vice President

 

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ASSIGNEES:

CITIBANK, N.A.,

as an Assignee

By:   /s/ Ryan Watson Name:   Ryan Watson Title:   Senior Vice President

 

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ASSIGNEES:

CADENCE BANK, N.A.,

as an Assignee

By:   /s/ Eric Broussard Name:   Eric Broussard Title:   Senior Vice President

 

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ASSIGNEES:

COMPASS BANK, N.A.,

as an Assignee

By:   /s/ Kathleen J. Bowen Name:   Kathleen J. Bowen Title:   Senior Vice
President

 

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ASSIGNEES:

ONEWEST BANK, FSB,

as an Assignee

By:   /s/ Sean Murphy Name:   Sean Murphy Title:   Executive Vice President

 

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TEXAS CAPITAL BANK, N.A.,

as an Assignee

By:   /s/ Grant W. Leigh Name:   Grant W. Leigh Title:   Vice President

 

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Consented to and Accepted:

CITIBANK, N.A.,

as Successor Administrative Agent and L/C Issuer

By   /s/ Ryan Watson   Ryan Watson   Senior Vice President

 

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Consented to and Accepted:       ROYAL BANK OF CANADA, as Existing
Administrative Agent and Collateral Agent     ROYAL BANK OF CANADA, as L/C
Issuer By   /s/ Susan Khokher     By   /s/ Leslie P. Vowell Name:   Susan
Khokher     Name:   Leslie P. Vowell Title:   Manager, Agency     Title:  
Attorney-in-Fact

 

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Consented to:

 

POSTROCK ENERGY SERVICES CORPORATION, as a Borrower By:  

/s/ David J. Klvac

  David J. Klvac, Chief Financial Officer   and Chief Accounting Officer
POSTROCK MIDCONTINENT PRODUCTION, LLC, as a Borrower, By:   POSTROCK ENERGY
SERVICES CORPORATION, Its sole member   By:  

/s/ David J. Klvac

    David J. Klvac, Chief Financial Officer and Chief Accounting Officer

 

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ANNEX 1

TO MASTER ASSIGNMENT AND ASSUMPTION

STANDARD TERMS AND CONDITIONS FOR

ASSIGNMENT AND ASSUMPTION

1. Representations and Warranties.

1.1 Assignors. Each Assignor: (a) represents and warrants that (i) it is the
legal and beneficial owner of the Assigned Interest specified next to its name
on Annex II hereto, (ii) such Assigned Interest is free and clear of any lien,
encumbrance or other adverse claim and (iii) it has full power and authority,
and has taken all action necessary, to execute and deliver this Master
Assignment and Assumption and to consummate the transactions contemplated
hereby; and (b) assumes no responsibility with respect to (i) any statements,
warranties or representations made in or in connection with the Existing Credit
Agreement or any other Loan Document, (ii) the execution, legality, validity,
enforceability, genuineness, sufficiency or value of the Loan Documents or any
collateral thereunder, (iii) the financial condition of the Borrowers, any of
their Subsidiaries or Affiliates or any other Person obligated in respect of any
Loan Document or (iv) the performance or observance by the Borrowers, any of
their Subsidiaries or Affiliates or any other Person of any of their respective
obligations under any Loan Document.

1.2. Assignees. Each Assignee: (a) represents and warrants that (i) it has full
power and authority, and has taken all action necessary, to execute and deliver
this Master Assignment and Assumption and to consummate the transactions
contemplated hereby and to become a Lender under the Existing Credit Agreement,
(ii) it meets all requirements of an Eligible Assignee under the Existing Credit
Agreement (subject to receipt of such consents as may be required under the
Existing Credit Agreement) in order to acquire the Pro Rata Share of the
Assigned Interests specified next to its name on Annex II hereto and become a
Lender, (iii) from and after the Effective Date, it shall be bound by the
provisions of the Existing Credit Agreement as a Lender thereunder and, to the
extent of such Pro Rata Share of the Assigned Interest, shall have the
obligations of a Lender thereunder, (iv) it has received a copy of the Amended
and Restated Credit Agreement, together with copies of the most recent financial
statements delivered pursuant to Section 6.01 of the Existing Credit Agreement,
as applicable, and such other documents and information as it has deemed
appropriate to make its own credit analysis and decision to enter into this
Master Assignment and Assumption and to purchase its Pro Rata Share of the
Assigned Interest on the basis of which it has made such analysis and decision
independently and without reliance on the Existing Administrative Agent,
Successor Administrative Agent or any other Lender, and (v) if it is a Foreign
Lender, attached to this Master Assignment and Assumption is any documentation
required to be delivered by it pursuant to the terms of the Existing Credit
Agreement, duly completed and executed by such Assignee; and (b) agrees that
(i) it will, independently and without reliance on the Existing Administrative
Agent, Successor Administrative Agent, any Assignor or any other Lender, and
based on such documents and information as it shall deem appropriate at the
time, continue to make its own credit decisions in taking or not taking action
under the Loan Documents, and (ii) it will perform in accordance with their
terms all of the obligations which by the terms of the Loan Documents are
required to be performed by it as a Lender.

 

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Annex I Page 1

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2. Payments. From and after the Effective Date, the Successor Administrative
Agent shall distribute all payments in respect of the Assigned Interests
(including payments of principal, interest, fees and other amounts) to the
appropriate Assignors as specified on Annex II hereto for amounts which have
accrued to but excluding the Effective Date and to the appropriate Assignees as
specified on Annex II hereto for amounts which have accrued from and after the
Effective Date.

3. General Provisions. This Master Assignment and Assumption shall be binding
upon, and inure to the benefit of, the parties hereto and their respective
successors and assigns. This Master Assignment and Assumption may be executed in
one or more counterparts, each of which shall be deemed an original, but all of
which together shall constitute one and the same agreement. Delivery of an
executed counterpart of a signature page of this Master Assignment and
Assumption by telecopy, facsimile, photocopy or by sending a scanned copy by
electronic mail shall be effective as delivery of an originally executed
counterpart of this Master Assignment and Assumption. Any signature page of a
counterpart may be detached therefrom without impairing the legal effect of the
signatures thereon and attached to another counterpart identical in form thereto
but having attached to it one or more additional signature pages signed by other
parties. This Master Assignment and Assumption shall be governed by, and
construed in accordance with, the law of the State of New York.

 

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Annex I Page 2

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ANNEX II

TO MASTER ASSIGNMENT AND ASSUMPTION

ASSIGNORS

 

Existing Lender

   Amount of Revolving
Commitment Assigned      Percentage of Assigned
Interest     Percentage of
Existing Lender’s
Assigned Interest
Assigned  

Royal Bank of Canada

   $ 19,897,731.38         20.303807520 %      100 % 

KeyBank National Association

   $ 10,093,090.67         10.299072112 %      100 % 

Wells Fargo Bank, N.A.

(combined with BNP)

   $ 11,184,015.98         11.412261204 %      100 % 

Amegy Bank National Association

   $ 5,920,339.27         6.041162520 %      100 % 

Societe Generale

   $ 9,302,018.41         9.491855520 %      100 % 

U.S. Bank, National Association

   $ 2,177,777.78         2.222222224 %      100 % 

Comerica Bank

   $ 11,008,647.62         11.233313898 %      100 % 

RB International Finance (USA) LLC, f/k/a

RZB Finance, LLC

   $ 3,427,721.10         3.497674592 %      100 % 

BOKF, NA, d/b/a Bank of Oklahoma

   $ 5,033,139.57         5.135856704 %      100 % 

Citibank, N.A.

   $ 3,920,000.00         4.000000000 %      100 % 

Compass Bank

   $ 6,101,490.31         6.226010520 %      100 % 

NZC Guggenheim Master Fund Ltd.

   $ 3,832,537.60         3.910752653 %      100 % 

SunTrust Bank

   $ 6,101,490.31         6.226010520 %      100 % 

TOTAL:

   $ 98,000,000.00         99.999999987 %      100 % 

ASSIGNEES

 

Lender

   Amount of Revolving
Commitment      Pro Rata Share of Assigned
Interests Acquired by
Assignee

Citibank, N.A.

   $ 26,000,000.00       28.888888889%

Cadence Bank, N.A.,

   $ 18,000,000.00       20.000000000%

Compass Bank

   $ 18,000,000.00       20.000000000%

OneWest Bank, FSB

   $ 18,000,000.00       20.000000000%

Texas Capital Bank, N.A.

   $ 10,000,000.00       11.111111111%

TOTAL:

   $ 90,000,000.00       100.000000000%

 

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Annex II Page 1