| 601 | Williams, Clayton Energy, Inc. | Houston, TX 77070 | Oil & Gas Operator | Mar 2025 |
| 602 | Williams-Cody, Inc. | Houston, TX 77060 | Oil & Gas Operator | May 1994 |
| 603 | Williamson Oil & Gas, Inc. | Shreveport, LA 71166 | Oil & Gas Operator | Dec 2024 |
| 604 | Wilson - Owens Production Co. | Longview, TX 75601 | Oil & Gas Operator | Nov 1998 |
| 605 | Winchester Production Co., LTD. | Shreveport, LA 71129 | Oil & Gas Operator | Sep 2008 |
| 606 | Winchester Production Company | Shreveport, LA 71129 | Oil & Gas Operator | Nov 2008 |
| 607 | Wind River Resources Inc | Tulsa, OK 74136-6381 | Oil & Gas Operator | Jun 2010 |
| 608 | Wisenbaker Production Company | Tyler, TX 75702 | Oil & Gas Operator | Oct 2011 |
| 609 | Woodbine Production Corporation | Kilgore, TX 75663 | Oil & Gas Operator | Mar 2025 |
| 610 | Wynn-Crosby Energy, Inc. | Houston, TX 77002 | Oil & Gas Operator | May 2005 |
| 611 | XTO Energy Inc. | Spring, TX 77389 | Oil & Gas Operator | Mar 2025 |
| 612 | Yep, LLC | Palestine, TX 75802 | Oil Operator | Jan 2017 |
| 613 | Young, Clint Inc. | Graham, TX 76450 | Oil & Gas Operator | Mar 2025 |