EXHIBIT 99.1


                               APACHE CORPORATION

                    CERTIFICATION OF CHIEF EXECUTIVE OFFICER
                           AND CHIEF FINANCIAL OFFICER


         I, G. Steven Farris, certify that the Quarterly Report of Apache
Corporation on Form 10-Q for the quarterly period ending June 30, 2002, fully
complies with the requirements of Section 13(a) or 15(d) of the Securities
Exchange Act of 1934 (15 U.S.C. Section 78m or Section 78o (d)) and that
information contained in such report fairly represents, in all material
respects, the financial condition and results of operations of Apache
Corporation.


/s/ G. Steven Farris
-------------------------------------------
By:      G. Steven Farris
Title:   President, Chief Executive Officer
         and Chief Operating Officer



         I, Roger B. Plank, certify that the Quarterly Report of Apache
Corporation on Form 10-Q for the quarterly period ending June 30, 2002, fully
complies with the requirements of Section 13(a) or 15(d) of the Securities
Exchange Act of 1934 (15 U.S.C. Section 78m or Section 78o (d)) and that
information contained in such report fairly represents, in all material
respects, the financial condition and results of operations of Apache
Corporation.


/s/ Roger B. Plank
------------------------------------
By:      Roger B. Plank
Title:   Executive Vice President
         and Chief Financial Officer