Exhibit
10.21


 


TERMINATION AND
RELEASE OF IRREVOCABLE CONTRACT GUARANTEE


 


THIS TERMINATION
AND RELEASE OF IRREVOCABLE CONTRACT GUARANTEE (this “Release”) is made
and entered into as of [•] [•], 2009, by and among C/R Cobalt
Investment Partnership, L.P., C/R Energy Coinvestment II, L.P., Riverstone
Energy Coinvestment III, L.P., C/R Energy III Cobalt Partnership, L.P.,
Carlyle/Riverstone Global Energy and Power Fund III, L.P., Carlyle Energy
Coinvestment III, L.P., First Reserve Fund XI, L.P., FR XI Onshore AIV, L.P.,
GS Capital Partners VI Fund, L.P., GS Capital Partners VI Offshore Fund, L.P.,
GS Capital Partners V Fund, L.P., GS Capital Partners V Offshore Fund, L.P., KERN
Energy Partners I LP, KERN
Energy Partners I U.S., LP, KERN Energy Partners II LP, KERN Energy Partners II U.S., LP,
Caisse de Dépôt et Placement du Québec, and The Board of Trustees of the Leland
Stanford Junior University (each a “Guarantor” and collectively, the “Guarantors”)
and ENSCO Offshore Company, a Delaware corporation (the “Contractor”).


 


W I T N E S S E T H:


 


WHEREAS, the
Guarantors entered into that certain Irrevocable Contract Guarantee, dated as
of May 5, 2008 (the “Guarantee”), in favor of the Contractor,
pursuant to which, as a condition to the Contractor’s entry into that certain
Offshore Daywork Drilling Contract, dated as of May 5, 2008 (the “Rig
Agreement”),  with Cobalt
International Energy, L.P. (the “Partnership”), the Guarantors
guaranteed certain payment obligations of the Partnership to the Contractor
under the Rig Agreement (any and all obligations of each Guarantor under the
Guarantee, the “Obligations”);


 


WHEREAS, the
Partnership is proposing to effect the sale of shares of common stock of a
newly formed corporation, that will wholly own the Partnership, to the public
in an initial public offering (the “IPO”);


 


WHEREAS, pursuant
to Section 8 of the Guarantee, each Guarantor is required to be released
from the Guarantee and its Obligations upon receipt by the Contractor of
reasonable substitute credit support reasonably acceptable to the Contractor in
the amount of the remaining Obligations of such Guarantor;


 


WHEREAS, effective
as of the date hereof, the Partnership has obtained [•] to provide a
credit support for the remaining Obligations of all the Guarantors (the “Substitute
Credit Support”);


 


WHEREAS, the
Contractor agrees and acknowledges that the Substitute Credit Support is a
reasonable substitute credit support for the remaining Obligations as required
pursuant to Section 8 of the Guarantee; and


 


WHEREAS, the
Contractor hereby agrees to release the Guarantors from their Obligations under
the Guarantee and terminate the Guarantee , effective as of the date hereof, on
the terms set forth in this Release.


 

















 


NOW, THEREFORE,
for good and valuable consideration, the receipt and sufficiency of which are
hereby acknowledged, the parties hereto agree as follows:


 


1.             Release.  In consideration of the receipt by the
Contractor of the Substitute Credit Support, as of the date hereof, the
Contractor (on behalf of itself and its successors and assigns) hereby fully
and forever releases, discharges and acquits each of the Guarantors (and their
respective subsidiaries, affiliates, past and present officers, directors,
partners, attorneys, employees, agents, and each of their assigns and their
respective predecessors and successors in interest) from the Guarantee and its
Obligations (including any and all obligations, liabilities, claims, demands,
actions, covenants, and debts of any kind or nature arising out of or relating
to the Guarantee).


 


2.             Termination.  The Guarantee is hereby terminated as of the date
hereof and, upon such termination, the Guarantors shall have no further
liabilities or obligations thereunder.


 


3.             Entire Agreement.  This Release contains the complete, exclusive
and final agreement between the Contractor and the Guarantors and supersedes
any and all prior agreements, arrangements or understandings between the
Contractor and the Guarantors relating to the subject matter hereof.  No oral understandings, statements, promises
or inducements contrary to the terms of this Release exist.  This Release may be modified only upon the
written agreement of the Contractor and the Guarantors.


 


4.             Counterparts.  This Release may be executed by facsimile or
in one or more counterparts, all of which together shall constitute one and the
same agreement.


 


5.             Governing Law.  This Release and the rights and obligations
of the parties hereto shall be governed by and construed and enforced in
accordance with the laws of the State of New York excluding any
conflict-of-laws rule or principle (whether of New York or any other
jurisdiction) that might refer the governance or the construction of this
Release to the law of another jurisdiction.


 


[REMAINDER OF PAGE INTENTIONALLY BLANK]


 


2

















 


IN WITNESS
WHEREOF, the parties hereto have caused this Release to be executed as of the
date set forth above.


 


 


	
   

  	
  ENSCO Offshore Company

  
	
   

  	
   

  
	
   

  	
   

  
	
   

  	
  By:

  	
   

  
	
   

  	
  Name:

  
	
   

  	
  Title:

  
	
   

  	
   

  
	
   

  	
   

  
	
   

  	
  C/R Cobalt Investment
  Partnership, L.P.

  
	
   

  	
  By: Carlyle/Riverstone
  Energy Partners II, L.P.,

  
	
   

  	
  its general partner

  
	
   

  	
  By: C/R Energy GP II,
  LLC, its general partner

  
	
   

  	
   

  
	
   

  	
   

  
	
   

  	
  By:

  	
   

  
	
   

  	
  Name:

  
	
   

  	
  Title:

  
	
   

  	
   

  
	
   

  	
   

  
	
   

  	
  C/R Energy Coinvestment
  II, L.P.

  
	
   

  	
  By:

  	
  Carlyle/Riverstone Energy Partners II, L.P.

  
	
   

  	
  By:

  	
  C/R Energy GP II, LLC

  
	
   

  	
   

  
	
   

  	
   

  
	
   

  	
  By:

  	
   

  
	
   

  	
  Name:

  
	
   

  	
  Title:

  
	
   

  	
   

  
	
   

  	
   

  
	
   

  	
  Riverstone Energy
  Coinvestment III, L.P.

  
	
   

  	
  By:

  	
  Riverstone Coinvestment
  GP, LLC

  
	
   

  	
  By:

  	
  Riverstone Holdings,
  LLC

  
	
   

  	
   

  
	
   

  	
   

  
	
   

  	
  By:

  	
   

  
	
   

  	
  Name:

  
	
   

  	
  Title:

  



 


[Signature
Page to Termination and Release of Irrevocable Contract Guarantee]


 

















 


	
   

  	
  C/R Energy III Cobalt
  Partnership, L.P.

  
	
   

  	
  By:

  	
  Carlyle/Riverstone Energy Partners III, L.P., 

  
	
   

  	
  its general partner

  
	
   

  	
  By:

  	
  C/R Energy GP III, LLC, its general partner

  
	
   

  	
   

  
	
   

  	
   

  
	
   

  	
  By:

  	
   

  
	
   

  	
  Name:

  
	
   

  	
  Title:

  
	
   

  	
   

  
	
   

  	
   

  
	
   

  	
  Carlyle/Riverstone
  Global Energy and Power Fund III, L.P.

  
	
   

  	
  By:

  	
  Carlyle/Riverstone
  Energy Partners III, L.P., 

  
	
   

  	
  its general partner

  
	
   

  	
  By:

  	
  C/R Energy GP III, LLC,
  its general partner

  
	
   

  	
   

  
	
   

  	
   

  
	
   

  	
  By:

  	
   

  
	
   

  	
  Name:

  
	
   

  	
  Title:

  
	
   

  	
   

  
	
   

  	
   

  
	
   

  	
  Carlyle Energy
  Coinvestment III, L.P.

  
	
   

  	
  By:

  	
  Carlyle Energy
  Coinvestment III GP, L.L.C.

  
	
   

  	
  By:

  	
  TCG Holdings, L.L.C.

  
	
   

  	
   

  
	
   

  	
   

  
	
   

  	
  By:

  	
   

  
	
   

  	
  Name:

  
	
   

  	
  Title:

  



 


[Signature
Page to Termination and Release of Irrevocable Contract Guarantee]


 

















 


	
   

  	
  GS Capital Partners VI
  Fund, L.P.

  
	
   

  	
  By:

  	
  GSCP VI Advisors, L.L.C.

  
	
   

  	
  its general partner

  
	
   

  	
   

  
	
   

  	
   

  
	
   

  	
  By:

  	
   

  
	
   

  	
  Name:

  
	
   

  	
  Title:

  
	
   

  	
   

  
	
   

  	
   

  
	
   

  	
  GS Capital Partners VI
  Offshore Fund, L.P.

  
	
   

  	
  By:

  	
  GSCP
  VI Offshore Advisors, L.L.C.

  
	
   

  	
  its general partner

  
	
   

  	
   

  
	
   

  	
   

  
	
   

  	
  By:

  	
   

  
	
   

  	
  Name:

  
	
   

  	
  Title:

  
	
   

  	
   

  
	
   

  	
   

  
	
   

  	
  GS Capital Partners V
  Fund, L.P.

  
	
   

  	
  By:

  	
  GSCP
  V Advisors, L.L.C.

  
	
   

  	
  its
  general partner

  
	
   

  	
   

  
	
   

  	
   

  
	
   

  	
  By:

  	
   

  
	
   

  	
  Name:

  
	
   

  	
  Title:

  
	
   

  	
   

  
	
   

  	
   

  
	
   

  	
  GS Capital Partners V
  Offshore Fund, L.P.

  
	
   

  	
  By:

  	
  GSCP
  V Offshore Advisors, L.L.C.

  
	
   

  	
  its
  general partner

  
	
   

  	
   

  
	
   

  	
   

  
	
   

  	
  By:

  	
   

  
	
   

  	
  Name:

  
	
   

  	
  Title:

  



 


[Signature
Page to Termination and Release of Irrevocable Contract Guarantee]


 

















 


	
   

  	
  First Reserve Fund XI,
  L.P.

  
	
   

  	
  By:

  	
  First
  Reserve GP XI, L.P.,

  
	
   

  	
  its
  general partner

  
	
   

  	
  By:  First Reserve GP XI, Inc.,

  
	
   

  	
  its
  general partner

  
	
   

  	
   

  
	
   

  	
   

  
	
   

  	
  By:

  	
   

  
	
   

  	
  Name:

  
	
   

  	
  Title:

  
	
   

  	
   

  
	
   

  	
   

  
	
   

  	
  FR XI Onshore AIV, L.P.

  
	
   

  	
  By:

  	
  First
  Reserve GP XI, L.P.,

  
	
   

  	
  its
  general partner

  
	
   

  	
  By:  First Reserve GP XI, Inc.,

  
	
   

  	
  its
  general partner

  
	
   

  	
   

  
	
   

  	
   

  
	
   

  	
  By:

  	
   

  
	
   

  	
  Name:

  
	
   

  	
  Title:

  



 


[Signature
Page to Termination and Release of Irrevocable Contract Guarantee]


 

















 


	
   

  	
  KERN Energy Partners I LP

  
	
   

  	
  By:

  	
  KERN
  Energy Partners Management Ltd.,

  
	
   

  	
  its general partner

  
	
   

  	
   

  
	
   

  	
   

  
	
   

  	
  By:

  	
   

  
	
   

  	
  Name:

  
	
   

  	
  Title:

  
	
   

  	
   

  
	
   

  	
   

  
	
   

  	
  KERN Energy Partners I U.S., LP

  
	
   

  	
  By:

  	
  KERN Energy Partners Management Ltd.,

  
	
   

  	
  its general partner

  
	
   

  	
   

  
	
   

  	
   

  
	
   

  	
  By:

  	
   

  
	
   

  	
  Name:

  
	
   

  	
  Title:

  
	
   

  	
   

  
	
   

  	
   

  
	
   

  	
  KERN Energy Partners II U.S., LP

  
	
   

  	
  By:

  	
  KERN Energy Partners Management Ltd.,

  
	
   

  	
  its
  general partner

  
	
   

  	
   

  
	
   

  	
   

  
	
   

  	
  By:

  	
   

  
	
   

  	
  Name:

  
	
   

  	
  Title:

  
	
   

  	
   

  
	
   

  	
   

  
	
   

  	
  KERN Energy Partners II LP

  
	
   

  	
  By:

  	
  KERN Energy Partners Management Ltd.,

  
	
   

  	
  its
  general partner

  
	
   

  	
   

  
	
   

  	
   

  
	
   

  	
  By:

  	
   

  
	
   

  	
  Name:

  
	
   

  	
  Title:

  



 


[Signature
Page to Termination and Release of Irrevocable Contract Guarantee]


 

















 


	
   

  	
  Caisse de Dépôt et Placement du Québec

  
	
   

  	
   

  
	
   

  	
  By:

  	
   

  
	
   

  	
  Name:

  
	
   

  	
  Title:

  
	
   

  	
   

  
	
   

  	
   

  
	
   

  	
  By:

  	
   

  
	
   

  	
  Name:

  
	
   

  	
  Title:

  
	
   

  	
   

  
	
   

  	
   

  
	
   

  	
  The
  Board of Trustees of the Leland Stanford Junior University

  
	
   

  	
   

  
	
   

  	
  By:

  	
  Stanford
  Management Company, a division

  
	
   

  	
   

  
	
   

  	
   

  
	
   

  	
  By:

  	
   

  
	
   

  	
  Name:

  
	
   

  	
  Title:

  



 


[Signature
Page to Termination and Release of Irrevocable Contract Guarantee]