| 601 | Ward Petroleum Corporation | Enid, OK 73702 | Oil & Gas Operator | Feb 2026 |
| 602 | Washita Production Company | Tulsa, OK 74136 | Oil & Gas Operator | May 2006 |
| 603 | Waterford Energy Inc | Oklahoma City, OK 73102 | Oil & Gas Operator | Nov 1998 |
| 604 | Weatherly Oil & Gas, LLC | Dallas, TX 75206 | Oil & Gas Operator | Jun 2026 |
| 605 | Weiser-Brown Operating Company | Magnolia, AR 71754 | Oil & Gas Operator | Jun 2026 |
| 606 | Western Oil And Gas Development Corp | Oklahoma City, OK 73103-3735 | Oil & Gas Operator | Mar 2026 |
| 607 | Weststar Oil & Gas Inc | Edmond, OK 73013 | Oil & Gas Operator | Mar 2026 |
| 608 | Whitaker Energy Inc | Humble, TX 77346-1798 | Oil & Gas Operator | Mar 2026 |
| 609 | White Goat Resources LLC | Yukon, OK 73099 | Oil & Gas Operator | Feb 2026 |
| 610 | White Stone LLC | Waynoka, OK 73860-4801 | Oil & Gas Operator | Mar 2026 |
| 611 | Whitehorse Inc | Saint Charles, MO 63303-4204 | Oil & Gas Operator | Sep 2015 |
| 612 | Whiting Oil And Gas Corporation | Houston, TX 77002 | Oil & Gas Operator | Jun 2026 |
| 613 | Whitmar Exploration Company | Denver, CO 80202 | Oil & Gas Operator | Feb 2026 |
| 614 | Whitmar Operating Company | Tulsa, OK 74103-3515 | Oil & Gas Operator | Apr 2009 |
| 615 | Wil-MC Oil Corporation The | Irving, TX 75015-2510 | Oil & Gas Operator | Mar 1999 |
| 616 | Wildhorse Operating Company | Ardmore, OK 73402 | Oil & Gas Operator | Jun 2026 |
| 617 | Will Energy Corporation | Dallas, TX 75201 | Oil & Gas Operator | Feb 2026 |
| 618 | Williford Energy Company | Tulsa, OK 74135 | Oil & Gas Operator | Jun 2026 |
| 619 | Williford Resources LLC | Tulsa, OK 74136-1020 | Oil & Gas Operator | Mar 2026 |
| 620 | WM Energy LLC | Asher, OK 74826 | Oil & Gas Operator | Mar 2026 |
| 621 | Woods Petroleum Corporation | Oklahoma City, OK 73112 | Oil & Gas Operator | Mar 2015 |
| 622 | Wynn-Crosby Operating LP | Dallas, TX 75201 | Oil & Gas Operator | Feb 2026 |
| 623 | Xanadu Exploration Company | Broken Arrow, OK 74014 | Oil & Gas Operator | Mar 2026 |
| 624 | Xeric Oil & Gas Corporation | Midland, TX 79702 | Oil & Gas Operator | Apr 2014 |
| 625 | XTO Energy Inc. | Spring, TX 77389 | Oil & Gas Operator | Jun 2026 |
| 626 | Yale Oil Association, Inc. | Oklahoma City, OK 73105 | Oil & Gas Operator | Mar 2026 |
| 627 | Zeal Production Company | Sperry, OK 74073-4714 | Oil & Gas Operator | Mar 2026 |