| 1 | Wacker Oil Inc | Houston, TX 77002 | Oil & Gas Operator | Aug 1996 |
| 2 | Wadi Petroleum Inc | Houston, TX 77014 | Oil & Gas Operator | May 2018 |
| 3 | Wagner & Brown, LTD. | Midland, TX 79702 | Oil & Gas Operator | Aug 2014 |
| 4 | Wagner Oil Company | Fort Worth, TX 76102 | Oil & Gas Operator | Oct 2025 |
| 5 | Wagner, Duer & Co. | Fort Worth, TX 76102 | Oil & Gas Operator | Jan 1999 |
| 6 | Walter Oil & Gas Corporation | Houston, TX 77002 | Oil & Gas Operator | Oct 2025 |
| 7 | Warbonnet Exploration Company | Houston, TX 77056 | Oil & Gas Operator | Apr 2016 |
| 8 | Weber Energy Corporation | Dallas, TX 75219 | Oil & Gas Operator | Feb 2017 |
| 9 | Welder Exploration & Prod., Inc. | San Antonio, TX 78212 | Oil & Gas Operator | Dec 2022 |
| 10 | Wheeler Operating Corporation | Fort Worth, TX 76109 | Oil & Gas Operator | Oct 2025 |
| 11 | White Marlin Operating Company, LLC | Houston, TX 77002 | Oil & Gas Operator | Oct 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 | Whitson, James A., Jr. | Houston, TX 77063 | Oil & Gas Operator | Nov 2011 |
| 17 | Wild Cat Operating Company | Victoria, TX 77903 | Oil & Gas Operator | Mar 2008 |
| 18 | Williams, Clayton Energy, Inc. | Houston, TX 77070 | Oil & Gas Operator | Oct 2025 |
| 19 | Williams, Clayton Energy, L.L.C | Midland, TX 79705 | Oil & Gas Operator | May 1993 |
| 20 | Williams, Clayton W., Jr., Inc. | Midland, TX 79705 | Oil & Gas Operator | Mar 2008 |
| 21 | Williams-Cody, Inc. | Houston, TX 77060 | Oil & Gas Operator | May 1994 |
| 22 | Wimco | Dallas, TX 75229 | Oil & Gas Operator | Jul 2008 |
| 23 | Wing Corporation | Houston, TX 77002 | Oil & Gas Operator | Jun 2000 |
| 24 | Winn Exploration Co., Inc. | Corpus Chrsti, TX 78401 | Oil & Gas Operator | Oct 2025 |
| 25 | Wiser Oil Co | Denver, CO 80202 | Oil & Gas Operator | Dec 2023 |
| 26 | Wolverine Exploration Company | Houston, TX 77002 | Oil & Gas Operator | May 2019 |
| 27 | Woodard Energy Company | Houston, TX 77042 | Oil & Gas Operator | Mar 2010 |
| 28 | WRT Energy Corporation | Oklahoma City, OK 73118 | Oil & Gas Operator | May 1998 |
| 29 | Wynn-Crosby Operating, LTD. | Dallas, TX 75201 | Oil & Gas Operator | Oct 2025 |