| 401 | W.D. Oil Company | Pampa, TX 79066 | Oil & Gas Operator | Oct 2001 |
| 402 | Wagner, Duer & Co. | Fort Worth, TX 76102 | Oil & Gas Operator | Jan 1999 |
| 403 | Wallis Energy, Inc. | Austin, TX 78746 | Oil & Gas Operator | Feb 2026 |
| 404 | Ward Oil Co. | Kilgore, TX 75663 | Oil & Gas Operator | Feb 2026 |
| 405 | WCS Oil & Gas Corporation | Dallas, TX 75209 | Oil & Gas Operator | Aug 2021 |
| 406 | Weatherly Oil & Gas, LLC | Dallas, TX 75206 | Oil & Gas Operator | Feb 2026 |
| 407 | Weathers Exploration, Inc. | Tyler, TX 75702 | Oil & Gas Operator | Feb 2026 |
| 408 | Weldon Corporation | Houston, TX 77056 | Oil Operator | Feb 2020 |
| 409 | West Mountain Operating Co, Inc. | Longview, TX 75604 | Oil & Gas Operator | Feb 2019 |
| 410 | Western Chief Operating, L.L.C. | Graham, TX 76450 | Oil & Gas Operator | Feb 2026 |
| 411 | Weststar Oil & Gas Inc | Edmond, OK 73013 | Oil & Gas Operator | Nov 2025 |
| 412 | White Rock Oil & Gas, LLC | Plano, TX 75024 | Oil & Gas Operator | Feb 2026 |
| 413 | Whiting Oil And Gas Corporation | Houston, TX 77002 | Oil & Gas Operator | Feb 2026 |
| 414 | Whiting Petroleum Corporation | Denver, CO 80290 | Oil & Gas Operator | Jan 2025 |
| 415 | Will-Drill Operating, L.L.C. | Shreveport, LA 71105 | Oil & Gas Operator | Feb 2026 |
| 416 | Williamson, Don B. | Athens, TX 75751 | Oil & Gas Operator | Mar 2002 |
| 417 | Wilson Operating Service Inc | Brownfield, TX 79316 | Oil & Gas Operator | Aug 2003 |
| 418 | Wilson, Don H., Inc. | Elkhart, TX 75839 | Oil & Gas Operator | May 2019 |
| 419 | Wing Corporation | Houston, TX 77002 | Oil & Gas Operator | Jun 2000 |
| 420 | Wisenbaker Production Company | Tyler, TX 75702 | Oil & Gas Operator | Oct 2011 |
| 421 | WJW Operating Co.,LLC | Austin, TX 78738 | Oil & Gas Operator | May 2002 |
| 422 | Wolverine Exploration Company | Houston, TX 77002 | Oil & Gas Operator | May 2019 |
| 423 | Woodbine Petroleum, Inc. | Dallas, TX 75204 | Oil & Gas Operator | Aug 2003 |
| 424 | Worldwide Exploration, Inc | Kilgore, TX 75663 | Oil & Gas Operator | Mar 2002 |
| 425 | WTR Operating LLC | Kilgore, TX 75663 | Oil & Gas Operator | Feb 2026 |
| 426 | XTO Energy Inc. | Spring, TX 77389 | Oil & Gas Operator | Feb 2026 |
| 427 | Yep, LLC | Palestine, TX 75802 | Oil Operator | Jan 2017 |
| 428 | Young Marshall R Oil Co | Fort Worth, TX 76107 | Oil & Gas Operator | Mar 2011 |
| 429 | Yuma E & P Company, Inc. | Houston, TX 77027 | Oil & Gas Operator | Feb 2026 |