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                                                                    EXHIBIT 10.3
 
                FIRST AMENDMENT TO LOAN AND SECURITY AGREEMENT
                                [July 30, 1991]

     This First Amendment to LOAN and Security Agreement (the "Amendment") is
made and entered into as of July 30, 1991, by and between RED MAN PIPE & SUPPLY
co., an oklahoma corporation ("Borrower"), and BARCLAYS BUSINESS CREDIT, INC., a
Connecticut corporation ("Lender").

                            PRELIMINARY STATEMENTS:

     1.  Borrower and Lender entered into that certain LOAN and Security
Agreement dated as of May 3, 1991, governing the terms of up to $25,000,000 in
revolving credit loans (the "Agreement").

     2.  Borrower and Lender desire to amend the Agreement to make certain
revisions more particularly described herein.

                                  AGREEMENTS:

     NOW, THEREFORE, in consideration of the agreements herein contained,
subject to the terms and conditions set forth herein, Borrower and Lender hereby
agree as follows, and agree that the amendments specified below shall be
effective from and after the date hereof and shall be incorporated into the
Agreement and shall supersede those provisions in the Agreement referenced as
follows:

     1.  Definitions. Terms used herein and defined in the Agreement shall have
the meanings set forth in the Agreement except as otherwise provided herein.

     2.  Interest and Charges.

         (a) Section 3.1(H)(i)(A) of the Agreement is hereby deleted, and in
     place thereof shall be the following:

             "(A) The Average Daily Availability for the six months ending
         October 31, 1991 shall equal or exceed twenty percent (20%) of the
         Average Daily Loan Balance for such period;"

         (b) Section 3.1(H)(ii)(A) of the Agreement is hereby deleted, and in
     place thereof shall be the following:

             "(A) The Average Daily Availability for the twelve months ending
         October 31, 1992 shall equal or exceed twenty percent (20%) of the
         Average Daily Loan Balance for such period;"



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         (c) Section 3.1(H)(iii)(A) of the Agreement is hereby deleted, and in
     place thereof shall be the following:

             "(A) The Average Daily Availability for the six months ending April
         3O, 1993 shall equal or exceed twenty percent (20%) of the Average
         Daily Loan Balance for such period;"

     3.  Conditions. The obligation of Lender to be bound by the provisions
hereof shall be subject to the fulfillment of the following conditions precedent
on or before the date hereof:

         (a) Lender shall have received the following, duly executed by each
     party thereto, other than Lender:

             (i)    this Amendment; and

             (ii)   all other documents Lender may reasonably request with
         respect to any matter relevant to this Amendment or the transactions
         contemplated hereby.

         (b) As of the date hereof, there shall exist no Default or Event of
     Default.

         (c) Borrower and Guarantor shall have performed and complied with all
     agreements and conditions contained in the Agreement and the other
     Agreements which are required to be performed or complied with by Borrower
     or Guarantor before or on the date hereof.

         (d) The representations and warranties contained in the Agreement, as
     amended hereby, and the other Agreements shall be true and correct in all
     material respects as of the date hereof, with the same force and effect as
     though made on and as of this date.

         (e) No material adverse change shall have occurred in the business
     operations, financial condition or prospects of Borrower or Guarantor, and
     no material adverse litigation shall be pending or, to the knowledge of
     Borrower or Guarantor, threatened, against Borrower or Guarantor.

         (f) All corporate and legal proceedings and all documents required to
     be completed and executed by the provisions of, and all instruments to be
     executed in connection with the transactions contemplated by, this
     Amendment and any related agreements shall be satisfactory in form and
     substance to Lender.

     4.  Expenses. Borrower shall pay all out-of-pocket expenses arising in
connection with the preparation, execution, delivery and

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administration of this Amendment, including, but not limited to, all reasonable
legal fees and expenses incurred by Lender.

     5.   Continued Effect. Except to the extent amended hereby, all terms,
provisions and conditions of the Agreement and all of the other Agreements shall
continue in full force and effect and shall remain enforceable and binding in
accordance with their respective terms. The Agreement, as amended hereby, shall
continue to secure the obligations described therein, and the other Agreements
shall continue to secure the obligations and indebtedness described therein,
whether or not such other Agreements shall be expressly supplemented or amended
in connection with this Amendment.

     6.   Counterparts. This Amendment may be executed in any number cf
counterparts, each of which shall for all purposes be deemed an original and
all of which are identical. All parties need not execute the same counterpart.

     EXECUTED as of the date first above written.

                              RED MAN PIPE & SUPPLY CO.

                              By: /s/ DEE PAIGE
                              Name: DEE PAIGE
                              Title: V.P. - FINANCE

                              BARCLAYS BUSINESS CREDIT, INC.

                              By: /s/ MICHAEL A.  PARKER
                              Name: MICHAEL A.  PARKER
                              Title: S.V.P.

The undersigned Guarantor, having guaranteed to Lender the payment of the
Obligations as such term is defined in the Unconditional Limited Guaranty (the
"Guaranty") executed by Guarantor on May 3, 1991, hereby acknowledges, confirms,
and agrees that (i) the execution and delivery of this Amendment does not alter,
affect, diminish, release or reduce his liability under the Guaranty, and (ii)
the Guaranty is in full force and effect to secure the obligations described
therein.

                              /s/ LEWIS B.  KETCHUM
                              LEWIS B. KETCHUM



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