<ARTICLE> 5 <LEGEND> THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM THE COMPANY'S FINANCIAL STATEMENTS AND IS QUALIFIED IN ITS ENTIRETY BY REFERENCE TO SUCH FINANCIAL STATEMENTS. </LEGEND> <RESTATED> <PERIOD-TYPE> 3-MOS 6-MOS 9-MOS YEAR <FISCAL-YEAR-END> DEC-31-1997 DEC-31-1997 DEC-31-1997 DEC-31-1997 <PERIOD-END> MAR-31-1997 JUN-30-1997 SEP-30-1997 DEC-31-1997 <CASH> 39,258 41,145 70,860 102,958 <SECURITIES> 213,465 196,624 312,305 363,137 <RECEIVABLES> 180,318 197,092 217,236 205,589 <ALLOWANCES> 0 0 0 0 <INVENTORY> 30,754 31,282 32,314 33,714 <CURRENT-ASSETS> 480,668 482,128 654,435 718,775 <PP&E> 1,544,633 1,705,878 1,764,091 1,821,906 <DEPRECIATION> 297,072 322,485 349,381 370,165 <TOTAL-ASSETS> 1,963,759 2,124,664 2,201,527 2,298,561 <CURRENT-LIABILITIES> 108,532 115,672 113,123 131,145 <BONDS> 400,000 400,000 400,000 400,000 <PREFERRED-MANDATORY> 0 0 0 0 <PREFERRED> 0 0 0 0 <COMMON> 684 696 1,393 1,393 <OTHER-SE> 1,249,900 1,398,374 1,464,198 1,534,134 <TOTAL-LIABILITY-AND-EQUITY> 1,963,759 2,124,664 2,201,527 2,298,561 <SALES> 0 0 0 0 <TOTAL-REVENUES> 204,733 433,267 683,764 956,093 <CGS> 0 0 0 0 <TOTAL-COSTS> 89,739<F1> 187,960<F1> 287,867<F1> 406,343<F1> <OTHER-EXPENSES> 30,688<F2> 62,772<F2> 96,349<F2> 129,877<F2> <LOSS-PROVISION> 0 0 0 0 <INTEREST-EXPENSE> 0 3,349 6,940 10,270 <INCOME-PRETAX> 87,014 187,403 306,741 430,061 <INCOME-TAX> 30,784 65,939 107,446 151,456 <INCOME-CONTINUING> 56,230 121,464 199,295 278,605 <DISCONTINUED> 0 0 0 0 <EXTRAORDINARY> 0 0 0 0 <CHANGES> 0 0 0 0 <NET-INCOME> 56,230 121,464 199,295 278,605 <EPS-PRIMARY> 0.41<F3> 0.88<F3> 1.44<F3> 2.01<F3> <EPS-DILUTED> 0.39<F3> 0.85<F3> 1.39<F3> 1.93<F3> <FN> <F1>Includes contract drilling expenses only. <F2>Includes other operating expenses. <F3>Per share amounts reflect the retroactive effect of the two-for-one stock split in the form of a stock dividend to stockholders of record on July 24, 1997. </FN>