EXHIBIT 7.1 [BAKER HUGHES LETTERHEAD] December 1, 1999 Tuboscope Inc. VIA FACSIMILE 2835 Holmes Road (713) 799-5183 Houston, Texas 77051 Attention: General Counsel Re: Agreement for the Purchase and Sale of the Baker Hughes Tubular Services Eastern...

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                                                                     EXHIBIT 7.1


                            [XXXXX XXXXXX LETTERHEAD]


                                                                December 1, 1999





Tuboscope Inc.                                                     VIA FACSIMILE
0000 Xxxxxx Xxxx                                                  (000) 000-0000
Houston, Texas 77051
Attention: General Counsel

         Re:      Agreement for the Purchase and Sale of the Xxxxx Xxxxxx
                  Tubular Services Eastern Hemisphere Division of Xxxxx Xxxxxx
                  Incorporated dated as of October 1, 1991

Gentlemen:

                  Xxxxx Xxxxxx Incorporated hereby terminates and irrevocably
waives its right contained in the last sentence of Section 8.12 of the
above-referenced Agreement to request the nomination of a person to your Board
of Directors.

                                         Very truly yours,

                                         XXXXX XXXXXX INCORPORATED


                                         By: /s/ XXX X. XXXXXX
                                         ---------------------------------------
                                                Xxx X. Xxxxxx
                                                Chairman of the Board, President
                                                and Chief Executive Officer


cc:      X. Xxxxx Xxxxxxxx, Xx.
         Xxxxx & Xxxxx, L.L.P.
         (facsimile: (000) 000-0000)

         Xxxxxxx Xxxxxx
         Xxxxxx & Xxxxxxx
         (facsimile: (000) 000-0000)