X0508 4 2026-02-03 0001423902 Western Midstream Partners, LP WES 0000797468 OCCIDENTAL PETROLEUM CORP /DE/ 5 GREENWAY PLAZA SUITE 110 HOUSTON TX 77046 true 0000856716 WESTERN GAS RESOURCES INC 1099 18TH STREET, SUITE 1200 DENVER CO 80202-1955 true 0001601306 APC Midstream Holdings, LLC 5 GREENWAY PLAZA SUITE 110 HOUSTON TX 77046 true 0001699285 Kerr-McGee Worldwide Corp 5 GREENWAY PLAZA SUITE 110 HOUSTON TX 77046 true 0001824936 Anadarko USH1 Corp 5 GREENWAY PLAZA SUITE 110 HOUSTON TX 77046 true 0001141185 KERR MCGEE CORP /DE 5 GREENWAY PLAZA SUITE 110 HOUSTON TX 77046 true false COMMON UNITS (LIMITED PARTNER INTERESTS) 2026-02-03 4 J 0 15307402 D 150374176 I See Footnotes On January 16, 2026, Western Gas Resources, Inc. ("WGRI") entered into a Unit Redemption Agreement with the Issuer and the other parties thereto, pursuant to which WGRI transferred and surrendered on February 3, 2026 an aggregate of 15,307,402 common units representing limited partner interests in the Issuer (the "Common Units") to the Issuer in connection with certain amendments to existing operating agreements, as described in the Unit Redemption Agreement. Following the transaction reported herein, WGRI holds 140,912,118 Common Units, APC Midstream Holdings, LLC ("APCMH") holds 457,849 Common Units and Anadarko USH1 Corporation ("AUSHI") holds 9,004,209 Common Units. WGRI also is the sole member of Western Midstream Holdings, LLC, the 2% economic general partner of the Issuer. OXY USA Inc. ("OXY USA") is a wholly owned subsidiary of Occidental Petroleum Corporation ("Occidental"). OXY USA owns 100% of the outstanding common stock of OXY Oil Partners, Inc. ("OOP"). OOP owns 100% of the outstanding common stock of Baseball Merger Sub 2, Inc. ("BMS"). Anadarko Petroleum Corporation ("APC") is a wholly owned subsidiary of BMS. APC owns (i) 100% of Anadarko Holding Company ("AHC") and (ii) indirectly, 100% of the common stock of WGRI and Kerr-McGee Corporation ("KMG"). WGRI is the sole member of APCMH. KMG and AHC together own 100% of the common stock of Kerr-McGee Worldwide Corporation ("KMWW"), and APC and KMWW together indirectly own 100% of the common stock of AUSH1. Accordingly, OXY USA, OOP, BMS, APC, AHC, WGRI, AUSH1, KMG, APCMH and KMWW are all direct or indirect wholly owned subsidiaries of Occidental. Due to the limitations of the U.S. Securities and Exchange Commission's electronic filing system, each of Occidental, OXY USA, OOP, BMS, APC and AHC are concurrently filing a Form 4 to report the transaction disclosed herein. /s/ Nicole E. Clark of Western Gas Resources, Inc. 2026-02-05 /s/ Nicole E. Clark of APC Midstream Holdings, LLC 2026-02-05 /s/ Nicole E. Clark of Kerr-McGee Worldwide Corporation 2026-02-05 /s/ Nicole E. Clark of Anadarko USH1 Corporation 2026-02-05 /s/ Nicole E. Clark of Kerr-McGee Corporation 2026-02-05