EXHIBIT
        10.5

      


      


      


      April
        1,
        2005

      


      


      Mr.
        Robert S. Beall

      1903
        Central Drive, Suite 102

      Bedford,
        Texas 76021

      


      Dr.
        Glenn
        S. Penny

      1004
        South Plainsman Road

      Marlow,
        OK 73055

      


      


      Gentlemen:

      


      The
        purpose of this letter agreement is to set forth our agreement as
        follows:

      


      	1.  	
              On
                the date hereof, Flotek Industries, Inc. (“Flotek”) has paid to Robert S.
                Beall (“Beall”) $225,511.20.

            


      


      	2.  	
              On
                the date hereof, Flotek has paid Glenn S. Penny (“Penny”) $4,062.67 and
                deliveed to Penny a promissory note in the original principal amount
                of
                $128,721.65.

            


      


      	3.  	
              The
                performance by Flotek of its obligations pursuant to Sections 1 and
                2 of
                this letter agreement shall constitute full performance of the obligations
                by Flotek and Chemical & Equipment Specialties, Inc. (“CESI”) of their
                obligations to Stimulation Chemicals, LLC (“StimChem”) and its members and
                affiliates in connection with the transactions entered into pursuant
                to
                (i) that certain agreement between CESI and StimChem dated January
                30,
                2003 (the “January Agreement”), and (ii) that certain agreement between
                CESI and StimChem dated August 25, 2003 (the “August
                Agreement”).

            


      


      	4.  	
              The
                January Agreement and the August Agreement have been and are hereby
                terminated.

            


      


      	5.  	
              Flotek
                and CESI hereby release each of Beall, Penny and StimChem, and the
                affiliates, managers, officers and representatives of StimChem, from
                any
                and all claims, liabilities, obligations, and causes of action whatsoever,
                known or unknown, including but not limited to obligations arising
                pursuant to (i) the January Agreement, (ii) the August Agreement,
                and/or
                (iii) previous negotiations or undertakings with respect to the
                same.

            


      


      
        
           

        

        
           

          
            

          

        

        
          
            Mr.
              Robert S. Beall

            Dr.
              Glenn
              S. Penny

            April
              1,
              2005

            Page
              2

          

        

         

         

      

      	6.  	
              Beall,
                Penny and StimChem hereby release each of Flotek and CESI, and their
                affiliates, and their respective directors, managers, officers and
                representatives, from any and all claims, liabilities, obligations
                and
                causes of action whatsoever, known or unknown, including but not
                limited
                to obligations arising pursuant to (i) the January Agreement, (ii)
                the
                August Agreement, and/or (iii) previous negotiations or undertakings
                with
                respect to the same.

            


      


      	7.  	
              An
                “affiliate” of a person shall be any person controlling, controlled by, or
                under common control with, that person. Each person who has released
                a
                claim hereunder on behalf of any of its affiliates shall indemnify
                the
                released party with respect to any claim asserted by its affiliate
                which
                is purported to be released hereunder.

            


      


      If
        the
        foregoing sets forth the terms of our agreement, please execute this letter
        where indicated below in order to establish a binding agreement under the
        laws
        of the State of Texas.

      
        	 	 	 
	 	Sincerely,
	 	 
	 	FLOTEK
                INDUSTRIES, INC.
	 
 	 
 	 
 
	 	By:  	/s/ Jerry
                D. Dumas, Sr.
	 	
                
Jerry
                D. Dumas, Sr., Chief Executive Officer




       

      
        	 	 	 
	 	CHEMICAL
                & EQUIPMENT SPECIALTIES, INC.
	 
 	 
 	 
 
	 	By:  	/s/ Jerry
                D. Dumas, Sr.
	 	
                
Jerry
                D. Dumas, Sr., Chief Executive Officer




      



      
        
           

        

        
           

          
            

          

        

        
           

          
            Mr.
              Robert S. Beall

            Dr.
              Glenn
              S. Penny

            April
              1,
              2005

            Page
              3

          

        

      


      


      ACCEPTED
        AND AGREED TO:

      


      


      /s/
        Robert S. Beall    

      Robert
        S.
        Beall

      


      


      /s/
        Glenn S. Penny    

      Glenn
        S.
        Penny

      


      STIMULATION
        CHEMICALS, LLC