| 501 | United Resources LP | Austin, TX 78746 | Oil & Gas Operator | Oct 2011 |
| 502 | Unitex Oil & Gas, L.L.C. | Midland, TX 79701 | Oil & Gas Operator | Sep 2026 |
| 503 | Uplands Resources Inc | Tulsa, OK 74103-4141 | Oil & Gas Operator | May 2026 |
| 504 | Uptex Operating Inc. | Dallas, TX 75201 | Oil & Gas Operator | May 2011 |
| 505 | Uptex Operating, L.P. | Dallas, TX 75201 | Oil & Gas Operator | May 2010 |
| 506 | V-F Petroleum Inc. | Midland, TX 79702 | Oil & Gas Operator | Sep 2026 |
| 507 | Valence Operating Company | Kingwood, TX 77339 | Oil & Gas Operator | Sep 2026 |
| 508 | Vanguard Operating, LLC | Houston, TX 77057 | Oil & Gas Operator | Jan 2021 |
| 509 | Vanguard Permian, LLC | Houston, TX 77057 | Oil & Gas Operator | Nov 2018 |
| 510 | Vantage Point Operating Co. | Houston, TX 77057 | Oil & Gas Operator | Dec 2014 |
| 511 | Verado Energy, Inc. | Allen, TX 75013 | Oil & Gas Operator | Oct 2025 |
| 512 | Vess Oil Corporation | Dallas, TX 75201 | Oil & Gas Operator | Sep 2026 |
| 513 | Victory Oil & Gas Inc | Gun Barrel Cy, TX 75156 | Oil & Gas Operator | Sep 2026 |
| 514 | Viola Production Inc | Dallas, TX 75251 | Oil & Gas Operator | Sep 2026 |
| 515 | Vision Minerals, LLC | Midland, TX 79701 | Oil & Gas Operator | Sep 2026 |
| 516 | Vista Resources, Inc. (A) | Midland, TX 79701 | Oil & Gas Operator | Feb 2000 |
| 517 | Viva Oil Company, Inc. | Kermit, TX 79745 | Oil & Gas Operator | Oct 2015 |
| 518 | Vogel, A. J., Inc. | Midland, TX 79702 | Oil & Gas Operator | Aug 1994 |
| 519 | W.H.D., Inc. | Euless, TX 76039 | Oil & Gas Operator | Aug 1998 |
| 520 | Wagner Oil Company | Fort Worth, TX 76102 | Oil & Gas Operator | Sep 2026 |
| 521 | Walker Oil And Gas LTD | Snyder, TX 79550 | Oil Operator | Sep 2026 |
| 522 | Walsh & Watts Inc | Aledo, TX 76008 | Oil & Gas Operator | Sep 2026 |
| 523 | Walton Producing Company | Breckenridge, TX 76424 | Oil & Gas Operator | Jul 2005 |
| 524 | Walton Properties LTD. | Midland, TX 79702 | Oil & Gas Operator | Feb 2004 |
| 525 | Wapiti Energy, LLC | Houston, TX 77024 | Oil & Gas Operator | Jul 2006 |
| 526 | Wash, Robert C. | Forsan, TX 79733 | Oil & Gas Operator | Nov 2000 |
| 527 | Wash, Robert C. Inc. | Forsan, TX 79733 | Oil & Gas Operator | Sep 2026 |
| 528 | Watusi Energy LLC | Midland, TX 79710 | Oil & Gas Operator | Sep 2026 |
| 529 | Wes-Tex Drilling Company | Abilene, TX 79604 | Oil & Gas Operator | Jan 2000 |
| 530 | West Inland Energy, Inc. | Fort Worth, TX 76179 | Oil & Gas Operator | Jan 2026 |
| 531 | Western Chief Operating, L.L.C. | Graham, TX 76450 | Oil & Gas Operator | Sep 2026 |
| 532 | Western Reserves Oil Co Inc | Midland, TX 79705 | Oil & Gas Operator | Oct 2020 |
| 533 | Westland Oil Development Corp. | Conroe, TX 77305 | Oil & Gas Operator | Mar 2008 |
| 534 | Whitt Investments, Inc. | Graham, TX 76450 | Oil Operator | Dec 2019 |
| 535 | Wilco Properties, Inc. | Dallas, TX 75205 | Oil & Gas Operator | Jan 2004 |
| 536 | Wind River Resources Inc | Tulsa, OK 74136-6381 | Oil & Gas Operator | Jun 2010 |
| 537 | Windham, L. E. | Rankin, TX 79778 | Oil & Gas Operator | Dec 1996 |
| 538 | Windham, L.E. Estate Of | Midland, TX 79702 | Oil & Gas Operator | Mar 2012 |
| 539 | Wiser Oil Co | Denver, CO 80202 | Oil & Gas Operator | Dec 2023 |
| 540 | WJC, Inc. | Post, TX 79356 | Oil & Gas Operator | Sep 2026 |
| 541 | WTP Energy, Inc. | Snyder, TX 79549 | Oil & Gas Operator | Sep 2026 |
| 542 | Xeric Oil & Gas Corporation | Midland, TX 79702 | Oil & Gas Operator | Apr 2014 |
| 543 | XTO Energy Inc. | Spring, TX 77389 | Oil & Gas Operator | Sep 2026 |
| 544 | Yale Oil Association, Inc. | Oklahoma City, OK 73105 | Oil & Gas Operator | Jun 2026 |
| 545 | Young, Marshall R., Oil Co. | Fort Worth, TX 76107 | Oil & Gas Operator | Mar 2011 |
| 546 | Yucca Energy, Inc. | Midland, TX 79702 | Oil & Gas Operator | Sep 2026 |