<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>

                             
<PERIOD-TYPE>                   6-MOS
<FISCAL-YEAR-END>                          DEC-31-1999
<PERIOD-END>                               JUN-30-1999
<CASH>                                          95,623
<SECURITIES>                                   585,601
<RECEIVABLES>                                  160,582
<ALLOWANCES>                                         0
<INVENTORY>                                     37,155
<CURRENT-ASSETS>                               923,674
<PP&E>                                       2,200,225
<DEPRECIATION>                                 562,475
<TOTAL-ASSETS>                               2,660,361
<CURRENT-LIABILITIES>                          149,234
<BONDS>                                        400,000
<PREFERRED-MANDATORY>                                0
<PREFERRED>                                          0
<COMMON>                                         1,393
<OTHER-SE>                                   1,820,688
<TOTAL-LIABILITY-AND-EQUITY>                 1,822,081
<SALES>                                              0
<TOTAL-REVENUES>                               443,374
<CGS>                                                0
<TOTAL-COSTS>                                  209,519<F1>
<OTHER-EXPENSES>                                83,141<F2>
<LOSS-PROVISION>                                     0
<INTEREST-EXPENSE>                               5,322
<INCOME-PRETAX>                                161,575
<INCOME-TAX>                                    56,530
<INCOME-CONTINUING>                            105,045
<DISCONTINUED>                                       0
<EXTRAORDINARY>                                      0
<CHANGES>                                            0
<NET-INCOME>                                   105,045
<EPS-BASIC>                                       0.77
<EPS-DILUTED>                                     0.74
<FN>
<F1>(1) INCLUDES CONTRACT DRILLING EXPENSES ONLY.
<F2>(2) INCLUDES OTHER OPERATING EXPENSES.
</FN>