| 501 | Union Pacific Resources Co. | Fort Worth, TX 76101 | Oil & Gas Operator | Jan 2001 |
| 502 | Urban Oil & Gas Group, LLC | Plano, TX 75074 | Oil & Gas Operator | Feb 2026 |
| 503 | V-F Petroleum Inc. | Midland, TX 79702 | Oil & Gas Operator | Feb 2026 |
| 504 | Vanguard Operating, LLC | Houston, TX 77057 | Oil & Gas Operator | Aug 2019 |
| 505 | Vanguard Permian, LLC | Houston, TX 77057 | Oil & Gas Operator | Nov 2018 |
| 506 | Verdad Oil & Gas Corporation | Dallas, TX 75235 | Oil & Gas Operator | Feb 2026 |
| 507 | Viola Production Inc | Dallas, TX 75251 | Oil & Gas Operator | Feb 2026 |
| 508 | Vista Petroleum Corp | Houston, TX 77277 | Oil & Gas Operator | Dec 1996 |
| 509 | Vista Resources, Inc. (A) | Midland, TX 79701 | Oil & Gas Operator | Feb 2000 |
| 510 | Vital Energy, Inc. | Tulsa, OK 74120 | Oil & Gas Operator | Feb 2026 |
| 511 | Wadi Petroleum Inc | Houston, TX 77014 | Oil & Gas Operator | May 2018 |
| 512 | Wagner, Duer & Co. | Fort Worth, TX 76102 | Oil & Gas Operator | Jan 1999 |
| 513 | Walter Exploration Inc | Dallas, TX 75206 | Oil & Gas Operator | May 2009 |
| 514 | Warrior Exploration LLC | Sapulpa, OK 74067-1912 | Oil & Gas Operator | Aug 2025 |
| 515 | Watusi Energy LLC | Midland, TX 79710 | Oil & Gas Operator | Feb 2026 |
| 516 | Wes-Tex Drilling Company | Abilene, TX 79604 | Oil & Gas Operator | Jan 2000 |
| 517 | West Texas Oil And Gas Oper.,Inc | Houston, TX 77046 | Oil & Gas Operator | Jul 2024 |
| 518 | Westerly Exploration, Inc. | Houston, TX 77256 | Oil & Gas Operator | Feb 2026 |
| 519 | Western Reserves Oil Co Inc | Midland, TX 79705 | Oil & Gas Operator | Oct 2020 |
| 520 | Westland Oil Development Corp. | Conroe, TX 77305 | Oil & Gas Operator | Mar 2008 |
| 521 | Weststar Oil & Gas Inc | Edmond, OK 73013 | Oil & Gas Operator | Dec 2025 |
| 522 | Williams, Clayton Energy, Inc. | Houston, TX 77070 | Oil & Gas Operator | Feb 2026 |
| 523 | Willow Bend Oil LLC | Dallas, TX 75206 | Oil & Gas Operator | Feb 2026 |
| 524 | Willow Creek Resources, Inc. | Midland, TX 79702 | Oil & Gas Operator | Feb 2009 |
| 525 | Winchester Operating, Inc. | Bryan, TX 77808 | Oil & Gas Operator | Aug 2001 |
| 526 | Wind River Energy, Inc. | Midland, TX 79710 | Oil & Gas Operator | Feb 2026 |
| 527 | Wind River Resources Inc | Tulsa, OK 74136-6381 | Oil & Gas Operator | Jun 2010 |
| 528 | Winn Operating, LLC | Kilgore, TX 75663 | Oil & Gas Operator | Feb 2026 |
| 529 | Wiseman, B. W., Jr. | Midland, TX 79702 | Oil & Gas Operator | Dec 2002 |
| 530 | Wiser Oil Co | Denver, CO 80202 | Oil & Gas Operator | Dec 2023 |
| 531 | Wood, McShane & Thams | Midland, TX 79702 | Oil & Gas Operator | Oct 1995 |
| 532 | Woodbine Petroleum, Inc. | Dallas, TX 75204 | Oil & Gas Operator | Aug 2003 |
| 533 | World Producers, Inc. | Dallas, TX 75201 | Oil & Gas Operator | Nov 1994 |
| 534 | Wynne Petroleum Co. | Fort Worth, TX 76116 | Oil & Gas Operator | Nov 1997 |
| 535 | Xeric Oil & Gas Company | Midland, TX 79702 | Oil & Gas Operator | Jul 1997 |
| 536 | Xeric Oil & Gas Corporation | Midland, TX 79702 | Oil & Gas Operator | Apr 2014 |
| 537 | Xog Operating LLC | Midland, TX 79702 | Oil & Gas Operator | Feb 2026 |
| 538 | Yates, Harvey E. Company | Roswell, NM 88201 | Oil & Gas Operator | Dec 2002 |
| 539 | Young Marshall R Oil Co | Fort Worth, TX 76107 | Oil & Gas Operator | Mar 2011 |
| 540 | Yukon Exploration Operating, LLC | Dallas, TX 75219 | Oil & Gas Operator | Feb 2026 |