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                                                                    EXHIBIT 3.16

                           ARTICLES OF INCORPORATION
                            OF POOL-AUSTRALIA, INC.

         We, the undersigned natural persons of the age of twenty-one years or
more, all of whom are citizens of the State of Texas, acting as incorporators of
a corporation under the Texas Business Corporation Act, do hereby adopt the
following Articles of Incorporation for such corporation:

                                 ARTICLE ONE

         The name of the corporation is Pool-Australia, Inc.

                                 ARTICLE TWO

         The period of its duration is perpetual.

                                ARTICLE THREE

         The purposes for which the corporation is organized are:

(1)      To engage in all phases of the oil and gas and mining business and
         related business activities, including, but not by way of limitation,
         the leasing, exploration of, development, production, and mining of
         oil and gas and mining properties.

(2)      To explore for, produce, mine, purchase and sell, store, process and
         manufacture, transport and distribute oil, gas, and all other minerals
         of whatsoever kind and nature, whether similar or dissimilar, except
         that the
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         corporation shall not engage directly in the oil pipe line business
         within the State of Texas.

(3)      To operate a business furnishing services and supplies to the oil, gas
         and mineral industry and for other surface and sub-surface
         exploration, development and production.

(4)      To manufacture, produce, purchase, or otherwise acquire, sell, or
         dispose of, distribute, mortgage, pledge, lease, repair, install,
         operate, deal in and with, whether as principal or agent, products,
         goods, appliances, wares, merchandise, fixtures, plants, structures,
         machinery, and materials of every kind and description; and to lend
         money for the carrying out of such purposes and to take and hold real
         and personal property for the payment of such funds so loaned.

(5)      To own all or any part of the stock of other corporations including
         but not limited to one or more corporations engaged in the oil and
         gas producing business and one or more corporations engaged in the oil
         pipe line business.

(6)      To engage in all phases of practical and scientific research.

(7)      To carry out all or any part of the foregoing purposes, either alone
         or in association with any individuals,

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         associations, partnerships or corporations, and in any state,
         territory, district, or possession of the United States, or in any
         foreign country, to the extent that such purposes are not forbidden by
         the law of such state, territory, district or possession of the United
         States, or by such foreign country.

(8)      In connection with the doing of all and everything or of anything
         necessary, suitable or proper for the accomplishment of any of the
         purposes or the attainment of any of the objects hereinabove set
         forth, to exercise all or any and to exercise each of the powers
         granted to corporations by the Texas Business Corporation Act or by
         any other statute or laws of the State of Texas.

                                  ARTICLE FOUR

         The aggregate number of shares which the corporation shall have
authority to issue is Four Thousand (4,000) of the par value of One Hundred
Dollars ($100) each. Each shareholder shall have preemptive rights.

                                  ARTICLE FIVE

         The corporation will not commence business until it has received for
the issuance of its shares consideration of the value of One Thousand Dollars
($1,000) consisting of money,

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labor done, or property actually received, which sum is not less than One
Thousand Dollars ($1,000).

                                  ARTICLE SIX

         The power to alter, amend or repeal the Bylaws or to adopt new Bylaws
shall be vested in the Board of Directors; provided, however, that any Bylaw or
Amendment thereto as adopted by the Board of Directors may be altered, amended
or repealed by vote of the shareholders entitled to vote for the election of
Directors or a new Bylaw in lieu thereof may be adopted by vote of such
shareholders. No Bylaw which has been altered, amended or adopted by such vote
of the shareholders may be altered, amended or repealed by vote of the Directors
until two years shall have expired since such action by vote of such
shareholders.

                                 ARTICLE SEVEN

         Each holder of stock of the corporation entitled to vote shall be
entitled to one vote for each share held. At each election of Directors each
shareholder entitled to vote at such election shall have the right to vote, in
accordance with the provisions of the Texas Business Corporation Act, the
number of shares owned by him for as many persons as there are Directors to be
elected and for whose election he has the right to vote; provided that
cumulative voting is expressly prohibited.


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                                 ARTICLE EIGHT

         The Post office address of its initial registered office is 301 South
Harwood Street, Dallas, Texas 75201, and the name of its initial registered
agent at such address is Michael G. Fortado.

                                  ARTICLE NINE

         The number of Directors constituting the initial Board of Directors is
seven, and the names and addresses of the persons who are to serve as Directors
until the first annual meeting of the shareholders or until their successors
are elected and qualified are:

         Roy E. Pitts . . . . . . .        301 S. Harwood Street
                                           Dallas, Texas  75201

         W. C. McCord . . . . . . .        301 S. Harwood Street
                                           Dallas, Texas  75201

         S. R. Singer . . . . . . .        301 S. Harwood Street
                                           Dallas, Texas  75201

         R. B. Williams . . . . . .        301 S. Harwood Street
                                           Dallas, Texas  75201

         W. T. Satterwhite  . . . .        301 S. Harwood Street
                                           Dallas, Texas  75201

         Frank M. Pool  . . . . . .        301 S. Harwood Street
                                           Dallas, Texas  75201

         R. G. Fowler . . . . . . .        301 S. Harwood Street
                                           Dallas, Texas  75201

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                                 ARTICLE TEN

        The names and addresses of the incorporators are:

        Roy E. Pitts      . . . . . .  301 S. Harwood Street
                                       Dallas, Texas  75201

        W. C. McCord      . . . . . .  301 S. Harwood Street
                                       Dallas, Texas  75201

        V. T. Satterwhite.  . . . . .  301 S. Harwood Street
                                       Dallas, Texas  75201

         IN WITNESS WHEREOF, we have hereunto set our hands, this 13th day of
September, 1972.

                                                /s/ ROY E. PITTS
                                                -----------------------------
                                                Roy E. Pitts


                                                /s/ W. C. MCCORD
                                                -----------------------------
                                                W. C. McCord


                                                /s/ W. T. SATTERWHITE
                                                -----------------------------
                                                W. T. Satterwhite

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THE STATE OF TEXAS             )
                               )
COUNTY OF DALLAS               )


         I, Lena J. Wicks, a Notary Public, do hereby certify that on this the
13th day of September, 1972, personally appeared before me ROY E. PITTS, W. C.
McCORD, and W. T. SATTERWHITE, who each being by me first duly sworn, severally
declared that they are the persons who signed the foregoing document as
incorporators, and that the statements contained therein are true.

                                        /s/ LENA J. WICKS
                                        ----------------------------
                                          Notary Public in and for 
                                            Dallas County, Texas

                                        LENA J. WICKS, NOTARY PUBLIC IN AND FOR
                                        DALLAS COUNTY, TEXAS