petro_8k-ex1001.htm


    EXHIBIT
      10.1

     

    
       

    

    D.B.
      ZWIRN SPECIAL OPPORTUNITIES FUND, L.P.

    745
      5th
      Avenue, 18th Floor

    New
      York,
      New York 10151

     

    October
      29, 2007

     

    PRC
      Williston LLC

    777
      Post
      Oak Blvd.

    Suite
      910

    Houston,
      Texas 77056

    Attention:
      Wayne P. Hall, Chief Executive Officer

    


    


    
      	
              Re:

            	
              Credit
                Agreement dated as of February 16, 2007 (as amended, supplemented
                or
                otherwise modified from time to time, the "Credit Agreement"), by
                and among PRC Williston LLC (the “Borrower”) D. B. Zwirn Special
                Opportunities Fund, L.P., as Administrative Agent ("Administrative
                Agent") and the financial institutions that are or may become lenders
                thereunder ("Lenders").

            


    

    


    Ladies
      and. Gentlemen:


     

    Reference
      is hereby made to the Credit Agreement for all purposes.  Any
      capitalized term used herein that is not defined herein shall have the meaning
      attributed to it in the Credit Agreement.  Unless otherwise noted
      herein, all references to sections herein shall refer to sections in the Credit
      Agreement.  You have requested that the Lenders and the Administrative
      Agent waive the requirements of Section 10.01 with respect to the financial
      covenants provided for therein for the fiscal quarter ending September 30,
      2007.  Administrative Agent and the Lenders agree that Borrower is not
      required to comply with Section 10.01 with respect to meeting the financial
      covenant ratios provided for therein for the fiscal quarter ending September
      30,
      2007.

     

    Except
      for the waivers as specifically
      provided for herein or in the letter agreements dated August 27, 2007 and
      September 19, 2007 between Administrative Agent and Borrower, Borrower
      acknowledges and agrees that there are no other amendments, modifications or
      waivers with respect to the Credit Agreement and that the Credit Agreement
      remains in full force and effect as originally entered into.  This
      Letter Agreement shall be deemed a Loan Document for all purposes.

     

    


     

    [Remainder
      of Page Intentionally Left Blank.]

     


    
      
         

      

      
         

        
          

        

      

      
         

      

    

     

    If
      the
      foregoing is acceptable to you please indicate your acknowledgement and
      agreement to the terms and provisions of this Letter Agreement by executing
      this
      Letter Agreement in the space provided below.

    


    
      
        	 	
                Sincerely,

              	 
	 	 	 
	 	 	 
	 	
                D.H.
                  ZWIRN SPECIAL OPPORTUNITIES FUND, L.P., as Administrative
                  Agent

              
	 	 	 
	 	
                By:

              	
                D.B.
                  Zwirn Partners, LLC, its general partner

              
	 	 	 
	 	 	 
	 	
                By:

              	
                /s/
                  Lawrence D.
                  Cutler                                       

              
	 	
                Name:

              	
                Lawrence
                  D. Cutler

              
	 	
                Title:

              	
                Authorized
                  Signatory

              


      



    


    


    AGREED
      TO
      AND ACCEPTED

    THIS
      __TH
      DAY OF OCTOBER, 2007:

    


    PRC
      WILLISTON LLC

    


    By:           /s/
      Wayne P.
      Hall                              


    Name:      Wayne
      P. Hall

    Title:        CEO