| 1 | W & W Services, Inc. | Palestine, TX 75802 | Oil & Gas Operator | Mar 2008 |
| 2 | Wagner & Brown, LTD. | Midland, TX 79702 | Oil & Gas Operator | Aug 2014 |
| 3 | Wagner, Duer & Co. | Fort Worth, TX 76102 | Oil & Gas Operator | Jan 1999 |
| 4 | Wainoco Oil & Gas Company | Houston, TX 77024 | Oil & Gas Operator | Dec 2005 |
| 5 | Wallis Energy, Inc. | Austin, TX 78746 | Oil & Gas Operator | Oct 2025 |
| 6 | Wentworth Energy, Inc. | Palestine, TX 75801 | Oil & Gas Operator | Jun 2009 |
| 7 | Westoil LLC | Austin, TX 78747 | Oil & Gas Operator | Oct 2025 |
| 8 | Whiting Petroleum Corporation | Denver, CO 80290 | Oil & Gas Operator | Jan 2025 |
| 9 | Whittington Operating Company | Houston, TX 77069 | Oil & Gas Operator | Oct 2025 |
| 10 | Will-Drill Production Co., Inc. | Shreveport, LA 71105 | Oil & Gas Operator | Oct 2025 |
| 11 | Williams Prod. Gulf Coast, L.P. | Benbrook, TX 76126 | Oil & Gas Operator | Jan 2012 |
| 12 | Williams, Clayton Energy, Inc. | Houston, TX 77070 | Oil & Gas Operator | Oct 2025 |
| 13 | Windrush Operating Co., L.L.C. | Longville, LA 70652 | Oil & Gas Operator | Oct 2025 |
| 14 | Wisenbaker Production Company | Tyler, TX 75702 | Oil & Gas Operator | Oct 2011 |
| 15 | Wiser Oil Co | Denver, CO 80202 | Oil & Gas Operator | Dec 2023 |