| 1 | Wagner Oil Company | Fort Worth, TX 76102 | Oil & Gas Operator | Nov 2024 |
| 2 | Wainoco Oil & Gas Company | Houston, TX 77024 | Oil & Gas Operator | Dec 2005 |
| 3 | Walter Oil & Gas Corporation | Houston, TX 77002 | Oil & Gas Operator | Nov 2024 |
| 4 | Warhorse Oil & Gas, LLC | | Oil & Gas Operator | Dec 2018 |
| 5 | Watson Energy, L.L.C. | | Oil & Gas Operator | Jun 2005 |
| 6 | WCC Energy Group LLC | | Oil & Gas Operator | Jul 2024 |
| 7 | Weaver Expl & Brock Pet Corp | | Oil & Gas Operator | Apr 1983 |
| 8 | Weaver Exploration Company | | Oil & Gas Operator | Jun 1991 |
| 9 | Westland Oil Development Corp. | Conroe, TX 77305 | Oil & Gas Operator | Mar 2008 |
| 10 | White Marlin Operating Company, LLC | Houston, TX 77002 | Oil & Gas Operator | Nov 2024 |
| 11 | White Oak Operating Company LLC | Houston, TX 77077 | Oil & Gas Operator | Nov 2024 |
| 12 | Whiting Petroleum Corporation | Denver, CO 80290 | Oil & Gas Operator | Jul 2024 |
| 13 | Whitton Company, Inc. | | Oil & Gas Operator | Jul 2020 |
| 14 | WHK, Inc. | | Oil & Gas Operator | Oct 1993 |
| 15 | Williams-Cody, Inc. | Houston, TX 77060 | Oil & Gas Operator | May 1994 |
| 16 | Wintershall Corporation | | Oil & Gas Operator | Oct 1989 |
| 17 | Wintershall Oil & Gas Corp | Houston, TX 77027 | Oil & Gas Operator | Jul 1989 |
| 18 | Wolverine Exploration Company | Houston, TX 77002 | Oil & Gas Operator | May 2019 |
| 19 | WRT Energy Corporation | Oklahoma City, OK 73118 | Oil & Gas Operator | May 1998 |