<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-31-1998
<PERIOD-END>                               SEP-30-1998
<CASH>                                         122,647
<SECURITIES>                                   443,187
<RECEIVABLES>                                  235,881
<ALLOWANCES>                                         0
<INVENTORY>                                     35,257
<CURRENT-ASSETS>                               865,887
<PP&E>                                       1,953,906
<DEPRECIATION>                                 463,357
<TOTAL-ASSETS>                               2,505,470
<CURRENT-LIABILITIES>                          142,478
<BONDS>                                        400,000
<PREFERRED-MANDATORY>                                0
<PREFERRED>                                          0
<COMMON>                                         1,393
<OTHER-SE>                                   1,690,911
<TOTAL-LIABILITY-AND-EQUITY>                 2,505,470
<SALES>                                              0
<TOTAL-REVENUES>                               925,372
<CGS>                                                0
<TOTAL-COSTS>                                  357,939<F1>
<OTHER-EXPENSES>                               116,689<F2>
<LOSS-PROVISION>                                     0
<INTEREST-EXPENSE>                              11,239
<INCOME-PRETAX>                                464,298
<INCOME-TAX>                                   163,209
<INCOME-CONTINUING>                            301,089
<DISCONTINUED>                                       0
<EXTRAORDINARY>                                      0
<CHANGES>                                            0
<NET-INCOME>                                   301,089
<EPS-PRIMARY>                                     2.17
<EPS-DILUTED>                                     2.07
<FN>
<F1>Includes contract drilling expenses only.
<F2>Includes other operating expenses.
</FN>