| 1 | Wagner & Brown, LTD. | Midland, TX 79702 | Oil & Gas Operator | Aug 2014 |
| 2 | Wagner, Duer & Co. | Fort Worth, TX 76102 | Oil & Gas Operator | Jan 1999 |
| 3 | Wainoco Oil & Gas Company | Houston, TX 77024 | Oil & Gas Operator | Dec 2005 |
| 4 | Wallis Energy, Inc. | Austin, TX 78746 | Oil & Gas Operator | Oct 2025 |
| 5 | Walter Oil & Gas Corporation | Houston, TX 77002 | Oil & Gas Operator | Oct 2025 |
| 6 | Wapiti Operating, LLC | Houston, TX 77043 | Oil & Gas Operator | Oct 2025 |
| 7 | Waters Eng. & Operating, Inc. | Corpus Chrsti, TX 78471 | Oil & Gas Operator | Sep 2013 |
| 8 | Welder Exploration & Prod., Inc. | San Antonio, TX 78212 | Oil & Gas Operator | Dec 2022 |
| 9 | Welderxp LTD. | San Antonio, TX 78212 | Oil & Gas Operator | Oct 2025 |
| 10 | Westland Oil Development Corp. | Conroe, TX 77305 | Oil & Gas Operator | Mar 2008 |
| 11 | Weststar Oil & Gas Inc | Edmond, OK 73013 | Oil & Gas Operator | Jul 2025 |
| 12 | White Oak Operating Company LLC | Houston, TX 77077 | Oil & Gas Operator | Oct 2025 |
| 13 | Whitehead Prod. Co., Inc. | Humble, TX 77338 | Oil & Gas Operator | Jun 2025 |
| 14 | Whiting Oil And Gas Corporation | Houston, TX 77002 | Oil & Gas Operator | Oct 2025 |
| 15 | Whiting Petroleum Corporation | Denver, CO 80290 | Oil & Gas Operator | Jan 2025 |
| 16 | Whitmar Exploration Company | Denver, CO 80202 | Oil & Gas Operator | Apr 2025 |
| 17 | Wilmoth Interests, Inc. | Marion Center, PA 15759 | Oil & Gas Operator | Mar 2025 |
| 18 | Wing Corporation | Houston, TX 77002 | Oil & Gas Operator | Jun 2000 |
| 19 | Wofford, C. J. | El Campo, TX 77437 | Oil & Gas Operator | Oct 2025 |
| 20 | Wood Energy Corporation | Baytown, TX 77520 | Oil & Gas Operator | Jun 1999 |
| 21 | Woodard Energy Company | Houston, TX 77042 | Oil & Gas Operator | Mar 2010 |
| 22 | Wynn-Crosby Operating, LTD. | Dallas, TX 75201 | Oil & Gas Operator | Oct 2025 |