| 1 | W B Powers Production Serv. | | Oil Operator | Feb 1991 |
| 2 | W. L. Estis | | Oil & Gas Operator | Dec 1999 |
| 3 | W. L. Puls & T. D. Rush | | Oil & Gas Operator | Dec 1980 |
| 4 | W. T. Waggoner Estate | | Oil & Gas Operator | Dec 1995 |
| 5 | Wagner & Brown | Midland, TX 79702 | Oil & Gas Operator | Aug 2014 |
| 6 | Wagner Oil Company | Fort Worth, TX 76102 | Oil & Gas Operator | Oct 2025 |
| 7 | Wainoco Oil & Gas Company | Houston, TX 77024 | Oil & Gas Operator | Dec 2005 |
| 8 | Walker La. Properties | | Oil & Gas Operator | Oct 1990 |
| 9 | Warwick Oil & Gas, Inc. | Houston, TX 77098 | Oil & Gas Operator | Feb 1993 |
| 10 | Westport Oil & Gas Company LP | The Woodlands, TX 77380 | Oil & Gas Operator | Feb 2007 |
| 11 | Westport Oil And Gas Company Inc | Denver, CO 80202 | Oil & Gas Operator | Feb 2002 |
| 12 | White Marlin Operating Company, LLC | Houston, TX 77002 | Oil & Gas Operator | Oct 2025 |
| 13 | White Oak Operating Company LLC | Houston, TX 77077 | Oil & Gas Operator | Oct 2025 |
| 14 | Whitton Company, Inc. | | Oil & Gas Operator | Jul 2020 |
| 15 | Windrush Operating Company | | Oil & Gas Operator | Jan 2009 |
| 16 | Wiser Oil Co | Denver, CO 80202 | Oil & Gas Operator | Dec 2023 |
| 17 | Wle, Inc. | | Oil & Gas Operator | Feb 2012 |
| 18 | WM. H. Kenny Consultants, LTD. | | Oil & Gas Operator | Nov 1991 |
| 19 | Woodbine Petroleum, Inc. | Dallas, TX 75204 | Oil & Gas Operator | Aug 2003 |
| 20 | Woolf & Magee, Inc. | | Oil & Gas Operator | Oct 1991 |