| 401 | Westar Energy, Inc. | Midland, TX 79705 | Oil & Gas Operator | Mar 2008 |
| 402 | Westlands Resources Corporation | Monrovia, CA 91016 | Oil & Gas Operator | Apr 2026 |
| 403 | Westpark Petroleum, Inc. | Austin, TX 78755 | Oil & Gas Operator | Apr 2026 |
| 404 | Westport Oil & Gas Company LP | The Woodlands, TX 77380 | Oil & Gas Operator | Feb 2007 |
| 405 | White Oak Operating Company LLC | Houston, TX 77077 | Oil & Gas Operator | Apr 2026 |
| 406 | Wildfire Energy Operating LLC | Houston, TX 77224 | Oil & Gas Operator | Apr 2026 |
| 407 | Wildhorse Resources MNGT Co, LLC | Oklahoma City, OK 73154 | Oil & Gas Operator | May 2019 |
| 408 | Williams, Clayton Energy, Inc. | Houston, TX 77070 | Oil & Gas Operator | Apr 2026 |
| 409 | Williams, Clayton Energy, L.L.C | Midland, TX 79705 | Oil & Gas Operator | May 1993 |
| 410 | Williams, Clayton W., Jr., Inc. | Midland, TX 79705 | Oil & Gas Operator | Mar 2008 |
| 411 | Williams-Cody, Inc. | Houston, TX 77060 | Oil & Gas Operator | May 1994 |
| 412 | Woodbine Acquisition LLC | Fort Worth, TX 76102 | Oil & Gas Operator | Nov 2014 |
| 413 | Wortham Oil & Gas | Conroe, TX 77301 | Oil & Gas Operator | Apr 2026 |
| 414 | Wright Brothers Energy, Inc. | Boerne, TX 78006 | Oil & Gas Operator | Apr 2026 |
| 415 | Yeti Exploration, LLC | Fort Worth, TX 76107 | Oil & Gas Operator | Apr 2026 |