| 1 | Wagner Oil Company | Fort Worth, TX 76102 | Oil & Gas Operator | Oct 2025 |
| 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 | Wapiti Operating, LLC | Houston, TX 77043 | Oil & Gas Operator | Oct 2025 |
| 6 | Ward, E. B. | Alice, TX 78333 | Oil & Gas Operator | Jun 2001 |
| 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 | West Tuleta Operating Corp. | Tuleta, TX 78162 | Oil & Gas Operator | May 2019 |
| 11 | Westridge Oil & Gas Properties | Mineral Wells, TX 76068 | Oil & Gas Operator | Oct 2025 |
| 12 | White Marlin Operating Company, LLC | Houston, TX 77002 | Oil & Gas Operator | Oct 2025 |
| 13 | Whiting Oil And Gas Corporation | Houston, TX 77002 | Oil & Gas Operator | Oct 2025 |
| 14 | Whiting Petroleum Corporation | Denver, CO 80290 | Oil & Gas Operator | Jan 2025 |
| 15 | Whittington Operating Company | Houston, TX 77069 | Oil & Gas Operator | Oct 2025 |
| 16 | Wild Cat Operating Company | Victoria, TX 77903 | Oil & Gas Operator | Mar 2008 |
| 17 | Winn Exploration Co., Inc. | Corpus Chrsti, TX 78401 | Oil & Gas Operator | Oct 2025 |
| 18 | Wiser Oil Co | Denver, CO 80202 | Oil & Gas Operator | Dec 2023 |
| 19 | Wofford, C. J. | El Campo, TX 77437 | Oil & Gas Operator | Oct 2025 |
| 20 | Wynn-Crosby Energy, Inc. | Houston, TX 77002 | Oil & Gas Operator | May 2005 |
| 21 | Wynn-Crosby Operating, LTD. | Dallas, TX 75201 | Oil & Gas Operator | Oct 2025 |