<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>
<MULTIPLIER> 1,000

                             
<PERIOD-TYPE>                   9-MOS
<FISCAL-YEAR-END>                          DEC-31-1999
<PERIOD-END>                               SEP-30-1999
<CASH>                                          97,981
<SECURITIES>                                   582,466
<RECEIVABLES>                                  153,036
<ALLOWANCES>                                         0
<INVENTORY>                                     38,093
<CURRENT-ASSETS>                               916,572
<PP&E>                                       2,277,554
<DEPRECIATION>                                 597,306
<TOTAL-ASSETS>                               2,694,313
<CURRENT-LIABILITIES>                          157,295
<BONDS>                                        400,000
<PREFERRED-MANDATORY>                                0
<PREFERRED>                                          0
<COMMON>                                         1,393
<OTHER-SE>                                   1,840,837
<TOTAL-LIABILITY-AND-EQUITY>                 2,694,313
<SALES>                                              0
<TOTAL-REVENUES>                               650,114
<CGS>                                                0
<TOTAL-COSTS>                                  324,642<F1>
<OTHER-EXPENSES>                               124,552<F2>
<LOSS-PROVISION>                                     0
<INTEREST-EXPENSE>                               7,474
<INCOME-PRETAX>                                219,788
<INCOME-TAX>                                    76,897
<INCOME-CONTINUING>                            142,891
<DISCONTINUED>                                       0
<EXTRAORDINARY>                                      0
<CHANGES>                                            0
<NET-INCOME>                                   142,891
<EPS-BASIC>                                       1.05
<EPS-DILUTED>                                     1.01
<FN>
<F1>Includes contract drilling expenses only.
<F2>Includes other operating expenses.
</FN>