| 601 | T.O.I. | Midland, TX 79710 | Oil & Gas Operator | Mar 2001 |
| 602 | Tall City Operations III LLC | Midland, TX 79701 | Oil & Gas Operator | Jun 2023 |
| 603 | Targa Midstream Services LLC | Houston, TX 77002 | Oil Operator | Mar 2023 |
| 604 | Taurus Exploration U.S.A., Inc. | Midland, TX 79705 | Oil & Gas Operator | Nov 1998 |
| 605 | Taurus Operating, Inc. | Midland, TX 79710 | Oil & Gas Operator | Apr 2026 |
| 606 | Team Operating, L.L.C. | Pinehurst, TX 77362 | Oil & Gas Operator | Apr 2026 |
| 607 | Teke Production LLC | Houston, TX 77269 | Oil Operator | Apr 2026 |
| 608 | Telesis Operating Co. | Fort Worth, TX 76116 | Oil & Gas Operator | Apr 2026 |
| 609 | Tempo Energy, Inc. | Midland, TX 79702 | Oil & Gas Operator | Apr 2026 |
| 610 | Texaco E & P Inc. | Houston, TX 77099 | Oil & Gas Operator | Apr 2026 |
| 611 | Texas Reexploration Operating LC | Fredericksbrg, TX 78624 | Oil & Gas Operator | Apr 2026 |
| 612 | Texas Vanguard Oil Company | Austin, TX 78720 | Oil & Gas Operator | Jan 2014 |
| 613 | Texland Petroleum Inc. | Fort Worth, TX 76102 | Oil & Gas Operator | Mar 2003 |
| 614 | Texland Petroleum, L.P. | Fort Worth, TX 76107 | Oil & Gas Operator | Apr 2026 |
| 615 | Three Rivers Operating Co LLC | Austin, TX 78735 | Oil & Gas Operator | Mar 2017 |
| 616 | Three Span Oil & Gas, Inc. | Midland, TX 79710 | Oil & Gas Operator | Apr 2026 |
| 617 | Three-B Oil Company, The | Monahans, TX 79756 | Oil & Gas Operator | Apr 2026 |
| 618 | Tiburon Oil & Gas, Inc. | Midland, TX 79701 | Oil & Gas Operator | Aug 2000 |
| 619 | Titan Resources I, Inc. | Midland, TX 79701 | Oil & Gas Operator | Jun 2000 |
| 620 | TMBR/Sharp Drilling, Inc. | Midland, TX 79703 | Oil & Gas Operator | Feb 2004 |
| 621 | Topat Oil Corporation | Midland, TX 79701 | Oil & Gas Operator | Sep 2017 |
| 622 | Torch Energy Services, Inc. | Houston, TX 77010 | Oil & Gas Operator | Sep 2011 |
| 623 | Tradition Resources LLC | Houston, TX 77002 | Oil & Gas Operator | Jan 2014 |
| 624 | Tradition Resources Oper, LLC | Houston, TX 77002 | Oil & Gas Operator | Jul 2017 |
| 625 | Traton Operating Company | Kingwood, TX 77339 | Oil & Gas Operator | Mar 2019 |
| 626 | Trek Petroleum Company, Inc. | Midland, TX 79707 | Oil & Gas Operator | Apr 2026 |
| 627 | Triag Energy Operating, Inc. | Midland, TX 79701 | Oil & Gas Operator | Jun 2014 |
| 628 | Trilogy Operating, Inc. | Midland, TX 79708 | Oil & Gas Operator | Apr 2026 |
| 629 | Trinity Bay Oil & Gas, Inc. | Lubbock, TX 79416 | Oil & Gas Operator | Apr 2026 |
| 630 | Triple "N" Services, Inc. | Midland, TX 79702 | Oil & Gas Operator | Apr 2026 |
| 631 | TS Oil, LLC | River Oaks, TX 76114 | Oil & Gas Operator | Apr 2026 |
| 632 | Tumbleweed Energy Limited | Midland, TX 79704 | Oil & Gas Operator | Dec 2022 |
| 633 | Two Black Bears Oil, Inc. | Midland, TX 79710 | Oil & Gas Operator | Sep 2003 |
| 634 | Two P Partners, LLC | Houston, TX 77056 | Oil & Gas Operator | Apr 2026 |
| 635 | TX Heat Of The Permian Basin Inc | Odessa, TX 79768 | Oil & Gas Operator | Dec 2021 |
| 636 | U S Energy Corp. Of Amer. Inc. | Cisco, TX 76437 | Oil & Gas Operator | Apr 2026 |
| 637 | Umc Petroleum Corporation | Houston, TX 77002 | Oil & Gas Operator | Mar 2015 |
| 638 | Union Oil Co Of California | Midland, TX 79706 | Oil & Gas Operator | Jan 2022 |
| 639 | Unit Petroleum Company | Tulsa, OK 74170 | Oil & Gas Operator | Apr 2026 |
| 640 | Unitex Oil & Gas, L.L.C. | Midland, TX 79701 | Oil & Gas Operator | Apr 2026 |
| 641 | Universal Resources Corp. | Salt Lake Cty, UT 84145 | Oil & Gas Operator | Jan 2000 |
| 642 | V-F Petroleum Inc. | Midland, TX 79702 | Oil & Gas Operator | Apr 2026 |
| 643 | Vanguard Operating, LLC | Houston, TX 77057 | Oil & Gas Operator | Aug 2019 |
| 644 | Vaquero Operating | FT Stockton, TX 79735 | Oil & Gas Operator | Apr 2026 |
| 645 | Vintage Petroleum, Inc. | Houston, TX 77046 | Oil & Gas Operator | Jan 2026 |
| 646 | Viola Production Inc | Dallas, TX 75251 | Oil & Gas Operator | Apr 2026 |
| 647 | Vista Resources, Inc. (A) | Midland, TX 79701 | Oil & Gas Operator | Feb 2000 |
| 648 | Vital Energy, Inc. | Houston, TX 77002 | Oil & Gas Operator | Apr 2026 |
| 649 | Viva Oil Company, Inc. | Kermit, TX 79745 | Oil & Gas Operator | Oct 2015 |
| 650 | Voyager Gas Corporation | Spring, TX 77379 | Oil & Gas Operator | Feb 2012 |
| 651 | Walbet | Monahans, TX 79756 | Oil & Gas Operator | Dec 1993 |
| 652 | Walbet, Inc. | Monahans, TX 79756 | Oil & Gas Operator | Apr 2026 |
| 653 | Wallace Operating Company LLC | Metairie, LA 70003 | Gas Operator | Apr 2026 |
| 654 | Walsh & Watts Inc | Aledo, TX 76008 | Oil & Gas Operator | Apr 2026 |
| 655 | Walton Properties LTD. | Midland, TX 79702 | Oil & Gas Operator | Feb 2004 |
| 656 | Warren Production Services | Caldwell, TX 77836 | Oil & Gas Operator | Apr 2026 |
| 657 | Waterbridge Texas Operating LLC | Houston, TX 77056 | Oil & Gas Operator | Apr 2026 |
| 658 | Watusi Energy LLC | Midland, TX 79710 | Oil & Gas Operator | Apr 2026 |
| 659 | West Inland Energy, Inc. | Fort Worth, TX 76179 | Oil & Gas Operator | Jan 2026 |
| 660 | Western Oil Company | Midland, TX 79702 | Oil & Gas Operator | Jul 2014 |
| 661 | Westport Oil & Gas Company LP | The Woodlands, TX 77380 | Oil & Gas Operator | Feb 2007 |
| 662 | Weststar Oil & Gas Inc | Edmond, OK 73013 | Oil & Gas Operator | Feb 2026 |
| 663 | White Oak Operating Company LLC | Houston, TX 77077 | Oil & Gas Operator | Apr 2026 |
| 664 | White Rock Oil & Gas, LLC | Plano, TX 75024 | Oil & Gas Operator | Apr 2026 |
| 665 | White Sail Resources LLC | Austin, TX 78731 | Oil Operator | Apr 2026 |
| 666 | White, Cecil | Monahans, TX 79756 | Oil & Gas Operator | Mar 2017 |
| 667 | Whiting Oil And Gas Corporation | Houston, TX 77002 | Oil & Gas Operator | Apr 2026 |
| 668 | Wilco Operating | Monahans, TX 79756 | Oil & Gas Operator | Apr 2026 |
| 669 | Williams Oil Company | Midland, TX 79710 | Oil & Gas Operator | Apr 2026 |
| 670 | Williams, Clayton Energy, Inc. | Houston, TX 77070 | Oil & Gas Operator | Apr 2026 |
| 671 | Wind River Energy, Inc. | Midland, TX 79710 | Oil & Gas Operator | Apr 2026 |
| 672 | WJC, Inc. | Post, TX 79356 | Oil & Gas Operator | Apr 2026 |
| 673 | Wood, McShane & Thams | Midland, TX 79702 | Oil & Gas Operator | Oct 1995 |
| 674 | Wortham, E. H. | Holliday, TX 76366 | Oil & Gas Operator | Mar 2008 |
| 675 | WPX Energy Permian, LLC | Oklahoma City, OK 73102 | Oil & Gas Operator | Apr 2026 |
| 676 | WTG Exploration | Midland, TX 79705 | Oil & Gas Operator | Apr 2026 |
| 677 | Wyco Oil & Gas LLC | Odessa, TX 79766 | Oil & Gas Operator | Jan 2024 |
| 678 | Xeric Oil & Gas Corporation | Midland, TX 79702 | Oil & Gas Operator | Apr 2014 |
| 679 | Xog Operating LLC | Midland, TX 79702 | Oil & Gas Operator | Apr 2026 |
| 680 | XTO Energy Inc. | Spring, TX 77389 | Oil & Gas Operator | Apr 2026 |
| 681 | Xtra Energy, LLC | Fort Worth, TX 76161 | Oil & Gas Operator | Apr 2026 |
| 682 | Yucca Energy, Inc. | Midland, TX 79702 | Oil & Gas Operator | Apr 2026 |