| 601 | Westwood Energy, Inc. | Abilene, TX 79608 | Oil & Gas Operator | May 2013 |
| 602 | WG Operating, Inc. | Tulsa, OK 74153 | Oil & Gas Operator | May 2012 |
| 603 | White, Frank | Abilene, TX 79604 | Oil & Gas Operator | Apr 2024 |
| 604 | Whiteside, H. W. | Abilene, TX 79604 | Oil & Gas Operator | Nov 1998 |
| 605 | Wilbanks, Bruce A. Company | Midland, TX 79702 | Oil & Gas Operator | Apr 2024 |
| 606 | Willowbend Investments, Inc. | Wichita Falls, TX 76307 | Oil & Gas Operator | Apr 2024 |
| 607 | Wilson, WM. B. Exploration Inc. | Midland, TX 79701 | Oil & Gas Operator | Jan 1996 |
| 608 | Winchester Energy Operating Co. | Austin, TX 78746 | Oil & Gas Operator | Apr 2024 |
| 609 | Winchester Production Co., LTD. | Shreveport, LA 71129 | Oil & Gas Operator | Sep 2008 |
| 610 | Windham Resources | Abilene, TX 79608 | Oil & Gas Operator | Apr 2024 |
| 611 | Windham Resources, Inc. | Tuscola, TX 79562 | Oil & Gas Operator | Feb 2004 |
| 612 | Window Operating Co., The | Coleman, TX 76834 | Oil & Gas Operator | Apr 2024 |
| 613 | Wishbone Texas Operating Co LLC | Houston, TX 77064 | Oil & Gas Operator | Jul 2019 |
| 614 | WJC, Inc. | Post, TX 79356 | Oil & Gas Operator | Apr 2024 |
| 615 | Wolcott, Ed Operating | Dallas, TX 75205 | Oil & Gas Operator | Oct 2000 |
| 616 | Woodbine Petroleum, Inc. | Dallas, TX 75204 | Oil & Gas Operator | Aug 2003 |
| 617 | Woodygreen Resources, LLC | Plano, TX 75093 | Oil & Gas Operator | Apr 2024 |
| 618 | Woodygreen Resources, LP | Abilene, TX 79608 | Oil & Gas Operator | Mar 2012 |
| 619 | World Producers, Inc. | Dallas, TX 75201 | Oil & Gas Operator | Nov 1994 |
| 620 | Xeric Oil & Gas Corporation | Midland, TX 79702 | Oil & Gas Operator | Apr 2014 |
| 621 | Xophi Energy, LLC | Arlington, TX 76006 | Oil & Gas Operator | Apr 2024 |
| 622 | Ziegler-Peru, Inc. | Houston, TX 77027 | Oil & Gas Operator | Dec 2019 |
| 623 | Zzron Inc. | Midland, TX 79704 | Oil & Gas Operator | Aug 2003 |