| 501 | Whitecap Energy L.L.C. | | Oil & Gas Operator | Sep 2018 |
| 502 | Whitehead Ross E | Lamont, OK 74643-0326 | Oil & Gas Operator | Nov 2014 |
| 503 | Whiting Oil And Gas Corporation | Houston, TX 77002 | Oil & Gas Operator | Jul 2025 |
| 504 | Wil-MC Oil Corporation The | Irving, TX 75015-2510 | Oil & Gas Operator | Mar 1999 |
| 505 | Wilco Oil & Gas Corporation | Oklahoma City, OK 73159-6229 | Oil & Gas Operator | Dec 2023 |
| 506 | Willa Mae Overman LLC | Ponca City, OK 74601-9451 | Oil & Gas Operator | Aug 2023 |
| 507 | Williams Doyle Dba BCF Gas | Tulsa, OK 74114-7099 | Oil & Gas Operator | Jul 2023 |
| 508 | Williams M H | Red Rock, OK 74651-0311 | Oil & Gas Operator | May 2023 |
| 509 | Winney Construction Company | Forks, WA 98331-0801 | Oil & Gas Operator | Jan 2013 |
| 510 | Withrow Oil Company Inc | Yukon, OK 73099-7712 | Oil & Gas Operator | Apr 2021 |
| 511 | Xanadu Exploration Company | Broken Arrow, OK 74014 | Oil & Gas Operator | May 2025 |
| 512 | Yale Oil Association, Inc. | Oklahoma City, OK 73105 | Oil & Gas Operator | May 2025 |
| 513 | Zenergy Inc | Tulsa, OK 74136 | Oil & Gas Operator | May 2025 |
| 514 | Zuhone William H | Mattoon, IL 61938-4019 | Oil & Gas Operator | Jan 2015 |