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                                                                   EXHIBIT 4.19

                       AMENDMENT TO STOCK OPTION PROGRAMS


         WHEREAS, the Board of Directors of Weatherford International, Inc. (the
"Company") has approved of the distribution to the Company's stockholders of all
of the stock of Grant Prideco, Inc. (the "Spin-Off") pursuant to the terms and
conditions set forth in the Distribution Agreement by and between the Company
and Grant Prideco, Inc. (the "Distribution Agreement");

         NOW, THEREFORE, the Company agrees as follows: (1) Effective as of the
Distribution Date as defined in the Distribution Agreement (the "Distribution
Date"), the Energy Ventures, Inc. Employees' Stock Option Plan, the Energy
Ventures, Inc. 1992 Employee Stock Option Plan, the Weatherford Enterra, Inc.
1991 Stock Option Plan, Taro Industries Limited Stock Option Plan and the
Weatherford International, Inc. 1998 Employee Stock Option Plan are hereby
amended by adding to each the following provisions:

         Notwithstanding any other provision of the Plan, the per-share exercise
price of each option granted under the Plan prior to September of 1998 shall be
adjusted pursuant to the application of the following formula: E (W-G)/W where E
is the original exercise price of the option; W is the market value per share of
Weatherford International, Inc.'s common stock, $1.00 par value ("WII Common
Stock"), as of the close of market on the last trading day before
"when-distributed" trading begins as reported by the New York Stock Exchange
("NYSE"); and G is the market value of a share of Grant Prideco, Inc. common
stock, $.01 par value ("GP Common Stock") determined initially by taking the
average of the high and low trading prices on the NYSE on the first full trading
date after "when-distributed" trading begins; and, following 30 consecutive
trading days after "when-distributed" trading begins, for options outstanding on
such date, the average of the last sales price per share of GP Common Stock on
the NYSE for each of the 30 consecutive trading days beginning on the date
"when-distributed" trading begins. Notwithstanding any other provision of the
Plan, if an optionee continues to be an employee of Grant Prideco, Inc. or any
of its affiliates (a "Grant Company") after the date as of which the
distribution by Weatherford International, Inc. to its stockholders of the stock
of Grant Prideco, Inc. is effective (the "Distribution Date"), he shall not be
deemed to terminate employment with Weatherford International, Inc. or its
subsidiaries within the meaning of the Plan until he is no longer an employee of
any Grant Company.

         Further, notwithstanding any other provision of the Plan, each option
granted under the Plan after August 31, 1998 to an optionee who continues to be
an employee of a Grant Company after the Distribution Date shall be canceled
upon the Distribution Date.

         Further, notwithstanding any other provision of the Plan, any option
granted under the Plan after August 31, 1998 to an optionee who remains an
employee of Weatherford International, Inc.

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or any of its subsidiaries or other affiliates, other than a Grant Company,
after the Distribution Date shall be adjusted as follows. The number of shares
of WII Common Stock for which such an option will be exercisable and the
exercise price for such option will be determined as provided in the following
formula:

     The adjusted exercise price for the option will equal         E (W-G)/W

     The number of shares of WII Common Stock subject to
     the adjusted option will equal                                NE/Pw

     Where      E =      The original exercise price of the option;

                N =      The original number of shares of WII Common Stock
                         subject to the option;

                G =      The market value of a share of GP Common
                         Stock (a) initially based on the average of
                         the high and low trading prices on the NYSE
                         on the first full trading date after
                         "when-distributed" trading begins, and (b)
                         following 30 consecutive trading days after
                         "when-distributed" trading begins, for
                         options remaining outstanding on such date,
                         the average of the last sales price per
                         share of GP Common Stock on the NYSE for
                         each of the 30 consecutive trading days
                         beginning on the date "when-distributed"
                         trading begins; and

                W =      The market value per share of WII Common
                         Stock as of the close of market on the last
                         trading day before "when-distributed"
                         trading begins as reported by the NYSE; and

                Pw =     The adjusted exercise price of the option
                         determined in accordance with the formula
                         set forth above.

     (2) Effective as of the Distribution Date, the Energy Ventures, Inc.
Amended and Restated Non-Employee Director Stock Option Plan and the Energy
Ventures, Inc. 1991 Non-Employee Director Stock Option Plan are hereby amended
by adding thereto the following provisions:

     Notwithstanding any other provision of the Plan, the per-share exercise
price of each option granted under the Plan shall be adjusted pursuant to the
application of the following formula: E (W-G)/W where E is the original exercise
price of the option; W is the market value per share of Weatherford
International, Inc. common stock, $1.00 par value, as of the close of market on
the last trading day before "when-distributed" trading begins as reported by the
New York Stock Exchange ("NYSE"); and G is the market value of a share of Grant
Prideco, Inc. common stock, $.01 par value ("GP Common Stock") determined
initially by taking the average of the high and low trading prices on the NYSE
on the first full trading date after "when-distributed" trading begins; and,
following 30 consecutive trading days after "when-distributed" trading begins,
for options outstanding on such date, the average of the last sales price per
share of GP Common Stock on the NYSE for each of the 30 consecutive trading days
beginning on the date "when-distributed" trading begins.


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         (3) Effective as of the Distribution Date, each option agreement and
warrant agreement entered into by the Company after August 31, 1998 with respect
to an optionee who remains an employee of the Company or any of its subsidiaries
or other affiliates other than Grant Prideco, Inc. or any of its subsidiaries or
other affiliates after the Distribution Date or who remains a non-employee
director of Weatherford International, Inc. after the Distribution Date is
hereby amended by adding thereto the following provisions:

     Further, notwithstanding any other provision of this Agreement, the option
granted hereunder shall be adjusted as follows: The number of shares of
Weatherford International, Inc. common stock, $1.00 par value ("WII Common
Stock"), for which such an option will be exercisable and the exercise price for
such option will be determinated as provided in the following formula:

     The adjusted exercise price for the option will equal           E (W-G)/W

     The number of shares of WII Common Stock subject to the
     adjusted option will equal                                      NE/Pw

     Where    E =        The original exercise price of the option;

              N =        The original number of shares of WII Common Stock
                         subject to the option;

              G =        The market value of a share of GP Common
                         Stock (a) initially based on the average of
                         the high and low trading prices on the NYSE
                         on the first full trading date after
                         "when-distributed" trading begins, and (b)
                         following 30 consecutive trading days after
                         "when-distributed" trading begins, for
                         options remaining outstanding on such date,
                         the average of the last sales price per
                         share of GP Common Stock on the NYSE for
                         each of the 30 consecutive trading days
                         beginning on the date "when-distributed"
                         trading begins; and

              W =        The market value per share of WII Common
                         Stock as of the close of market on the last
                         trading day before "when-distributed"
                         trading begins as reported by the NYSE; and

              Pw =       The adjusted exercise price of the option
                         determined in accordance with the formula
                         set forth above.

         (4) Effective as of the Distribution Date, each option agreement
entered into by the Company before September 1, 1998 with respect to an optionee
who remains an employee of the Company or any of its subsidiaries or other
affiliates other than Grant Prideco, Inc. or any of its


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subsidiaries or other affiliates after the Distribution Date is hereby amended
by adding thereto the following provisions:

         Notwithstanding any other provision of this Agreement, the per-share
exercise price of the option granted hereunder shall be adjusted pursuant to the
application of the following formula: E (W-G)/W where E is the original exercise
price of the option; W is the market value per share of Weatherford
International, Inc.'s common stock, $1.00 par value ("WII Common Stock"), as of
the close of market on the last trading day before "when-issued" trading begins
as reported by the New York Stock Exchange ("NYSE"); and G is the market value
of a share of Grant Prideco, Inc. common stock, $.01 par value ("GP Common
Stock") determined initially by taking the average of the high and low trading
prices on the NYSE on the first full trading date after "when-distributed"
trading begins; and, following 30 consecutive trading days after
"when-distributed" trading begins, for options outstanding on such date, the
average of the last sales price per share of GP Common Stock on the NYSE for
each of the 30 consecutive trading days beginning on the date "when-distributed"
trading begins.

         IN WITNESS WHEREOF, the Company has caused this Amendment to Stock
Option Programs to be executed by its duly authorized officer.


                                   WEATHERFORD INTERNATIONAL, INC.


DATE:                              BY:
    --------------------              -----------------------------------------
                                                  Curtis W. Huff
                                      Executive Vice President, Chief Financial
                                        Officer, General Counsel and Secretary


















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