| 401 | Targa Midstream Services LLC | Houston, TX 77002 | Oil Operator | Mar 2023 |
| 402 | Taubert & Steed | Wichita Falls, TX 76301 | Oil & Gas Operator | Aug 2001 |
| 403 | TC Oil And Gas, LLC | Denton, TX 76205 | Oil Operator | Apr 2024 |
| 404 | TCS Petroleum Co., LLC | Abilene, TX 79608 | Oil & Gas Operator | Apr 2024 |
| 405 | TDC Engineering, Inc. | Abilene, TX 79604 | Oil & Gas Operator | Apr 2024 |
| 406 | Tech Resources, Inc. | Georgetown, TX 78628 | Oil & Gas Operator | Dec 2001 |
| 407 | Telesis Operating Co. | Fort Worth, TX 76116 | Oil & Gas Operator | Apr 2024 |
| 408 | Tex-Ann Oil & Gas Services, Inc. | Abilene, TX 79608 | Oil & Gas Operator | Apr 2024 |
| 409 | Thomas Oil And Gas Inc. | San Angelo, TX 76906 | Oil & Gas Operator | May 2019 |
| 410 | Thorp Petroleum Corporation | Houston, TX 77002 | Oil & Gas Operator | Feb 2014 |
| 411 | THP Operating LLC | Santa Anna, TX 76878 | Oil & Gas Operator | Apr 2024 |
| 412 | Tiki Oil & Gas, LLC | Midland, TX 79704 | Oil Operator | Apr 2024 |
| 413 | Tipperary Oil & Gas Corp | Denver, CO 80202 | Oil & Gas Operator | May 2014 |
| 414 | TKP Petroleum, Inc. | Lubbock, TX 79464 | Oil & Gas Operator | Apr 2024 |
| 415 | Toc Energy Resources, LLC | Fort Worth, TX 76107 | Oil & Gas Operator | Apr 2024 |
| 416 | Topat Oil Corporation | Midland, TX 79701 | Oil & Gas Operator | Sep 2017 |
| 417 | Trans Oil Marketing LLC | Abilene, TX 79602 | Oil Operator | Aug 2023 |
| 418 | Trek Resources, Inc. | Dallas, TX 75207 | Oil & Gas Operator | Apr 2024 |
| 419 | Trend Exploration I LLC | Midland, TX 79701 | Oil & Gas Operator | May 2011 |
| 420 | Trey Exploration, Inc. | San Angelo, TX 76901 | Oil & Gas Operator | Dec 2020 |
| 421 | Trilogy Operating, Inc. | Midland, TX 79708 | Oil & Gas Operator | Apr 2024 |
| 422 | Tucker Drilling Company, Inc. | San Angelo, TX 76903 | Oil & Gas Operator | Jul 1996 |
| 423 | Twin Oaks Construction Company | Irving, TX 75063 | Oil & Gas Operator | Apr 2024 |
| 424 | TX Lone Star Operating Co, LLC | Sulphur SPGS, TX 75483 | Oil & Gas Operator | Apr 2024 |
| 425 | TXP, Incorporated | San Angelo, TX 76906 | Oil & Gas Operator | Apr 2024 |
| 426 | Txu Gas Company | Dallas, TX 75201 | Oil & Gas Operator | Sep 2004 |
| 427 | Txu Lone Star Pipeline | Dallas, TX 75201 | Oil & Gas Operator | Oct 2003 |
| 428 | Union Pacific Resources Co. | Fort Worth, TX 76101 | Oil & Gas Operator | Sep 2002 |
| 429 | Union Seaboard Corporation | Houston, TX 77024 | Oil & Gas Operator | Mar 2008 |
| 430 | Unit Petroleum Company | Tulsa, OK 74170 | Oil & Gas Operator | Apr 2024 |
| 431 | Upstream Properties, LLC | Southlake, TX 76092 | Oil & Gas Operator | Apr 2024 |
| 432 | V-F Petroleum Inc. | Midland, TX 79702 | Oil & Gas Operator | Apr 2024 |
| 433 | Vaca Operating Company LLC | Pacific PLSDS, CA 90272 | Oil & Gas Operator | Aug 2017 |
| 434 | Valley Resources, Inc. | Abilene, TX 79608 | Oil & Gas Operator | Aug 2003 |
| 435 | Vanguard Operating, LLC | Houston, TX 77057 | Oil & Gas Operator | Feb 2021 |
| 436 | Vanguard Permian LLC | Houston, TX 77057 | Oil & Gas Operator | Nov 2018 |
| 437 | Vaquero Operating | FT Stockton, TX 79735 | Oil & Gas Operator | Apr 2024 |
| 438 | Vaughn Petroleum, Inc. | Dallas, TX 75219 | Oil & Gas Operator | May 2004 |
| 439 | Verdad Oil & Gas Corporation | Dallas, TX 75235 | Oil & Gas Operator | Apr 2024 |
| 440 | Vista Resources, Inc. (A) | Midland, TX 79701 | Oil & Gas Operator | Feb 2000 |
| 441 | W.O.G., Inc. | Midland, TX 79702 | Oil & Gas Operator | Mar 2008 |
| 442 | Walbet | Monahans, TX 79756 | Oil & Gas Operator | Dec 1993 |
| 443 | Walbet, Inc. | Monahans, TX 79756 | Oil & Gas Operator | Apr 2024 |
| 444 | Walsh Resources, Inc. | Tyler, TX 75713 | Oil & Gas Operator | Apr 2024 |
| 445 | Watco Energy, Inc. | Tyler, TX 75713 | Oil & Gas Operator | Apr 1996 |
| 446 | Wes-Tex Drilling Company | Abilene, TX 79604 | Oil & Gas Operator | Jan 2000 |
| 447 | West Bay Exploration Company | Muenster, TX 76252 | Oil & Gas Operator | Feb 2024 |
| 448 | Western Pride Resources, Inc. | Jacksboro, TX 76458 | Oil & Gas Operator | Jan 2011 |
| 449 | Western Reserves Oil Co Inc | Midland, TX 79705 | Oil & Gas Operator | Oct 2020 |
| 450 | Westland Oil Development Corp. | Conroe, TX 77305 | Oil & Gas Operator | Mar 2008 |
| 451 | Wetwick DRLG. & Prod. | Carlsbad, TX 76934 | Oil Operator | Apr 2024 |
| 452 | Whitehawk Production Company | Midland, TX 79710 | Oil & Gas Operator | Apr 2024 |
| 453 | Wilbanks, Bruce A. | Midland, TX 79701 | Oil & Gas Operator | Aug 1996 |
| 454 | Wilbanks, Bruce A. Company | Midland, TX 79702 | Oil & Gas Operator | Apr 2024 |
| 455 | Wilshire Oil Co. Of Texas | Oklahoma City, OK 73102 | Oil & Gas Operator | Mar 2004 |
| 456 | Wilson, WM. B. Exploration Inc. | Midland, TX 79701 | Oil & Gas Operator | Jan 1996 |
| 457 | Wiser Oil Co | Denver, CO 80202 | Oil & Gas Operator | Dec 2019 |
| 458 | Yuma E & P Company, Inc. | Houston, TX 77027 | Oil & Gas Operator | Apr 2024 |
| 459 | Zachry Oil And Gas Properties | Midland, TX 79708 | Oil & Gas Operator | Apr 2024 |