| 401 | Thomas, R. W. Inc. | Norman, OK 73070 | Oil & Gas Operator | Apr 2015 |
| 402 | Thomas, T. N. Oil Company | Aiken, SC 29801 | Oil & Gas Operator | Dec 2025 |
| 403 | Thompson Oil Co. | Corsicana, TX 75151 | Oil & Gas Operator | Sep 2025 |
| 404 | Thompson Operating Co. | Abernathy, TX 79311 | Oil & Gas Operator | Aug 1994 |
| 405 | Thompson, J. Cleo | Dallas, TX 75201 | Oil & Gas Operator | May 2024 |
| 406 | Thompson, Joe L., Inc. | Oklahoma City, OK 73132 | Oil & Gas Operator | Oct 2005 |
| 407 | Thompson, Mark P. | Graham, TX 76450 | Oil & Gas Operator | Dec 2025 |
| 408 | Thompson, Richard W. Inc. | Plano, TX 75024 | Oil & Gas Operator | Dec 2025 |
| 409 | Thor Operating Company | Tyler, TX 75710 | Oil & Gas Operator | Dec 1995 |
| 410 | Thor-Max Operating, Inc. | Plano, TX 75025 | Oil & Gas Operator | Dec 2025 |
| 411 | Thornberry Oilfield Service, Inc | Conroe, TX 77302 | Oil & Gas Operator | Aug 2003 |
| 412 | Thornton Oil Co. | Abilene, TX 79603 | Oil & Gas Operator | Aug 2003 |
| 413 | Thornton, Michael D. | Breckenridge, TX 76424 | Oil & Gas Operator | Nov 1995 |
| 414 | Thorp Petroleum Corporation | Houston, TX 77002 | Oil & Gas Operator | Feb 2014 |
| 415 | THP Operating LLC | Santa Anna, TX 76878 | Oil & Gas Operator | Dec 2025 |
| 416 | Thrall Operating Company, Inc. | Dallas, TX 75240 | Oil & Gas Operator | Dec 2025 |
| 417 | Thrash, Afton | Kilgore, TX 75663 | Oil & Gas Operator | Apr 1996 |
| 418 | Three Arrow Operating Company | Midland, TX 79705 | Oil & Gas Operator | Feb 2018 |
| 419 | Three B Corporation | Fort Worth, TX 76179 | Gas Operator | Jun 2009 |
| 420 | Three B Operating, Inc. | Graham, TX 76450 | Oil & Gas Operator | Dec 2025 |
| 421 | Three B, LP | Fort Worth, TX 76179 | Gas Operator | Dec 2025 |
| 422 | Three C Consulting, Inc. | Magnolia, TX 77355 | Oil & Gas Operator | Aug 1995 |
| 423 | Three C Exploration, LLC | Hebbronville, TX 78361 | Oil & Gas Operator | Dec 2025 |
| 424 | Three D Submersible Pumps, Inc. | Heavener, OK 74937 | Oil & Gas Operator | Aug 2003 |
| 425 | Three Forks Operating Co, LLC | Flatonia, TX 78941 | Oil & Gas Operator | Dec 2025 |
| 426 | Three Forks Resources, LLC | Wheat Ridge, CO 80033 | Oil & Gas Operator | Dec 2025 |
| 427 | Three G Oil Co | Baird, TX 79504 | Oil & Gas Operator | Jun 2004 |
| 428 | Three J Energy, Inc. | Seguin, TX 78155 | Oil & Gas Operator | Dec 2025 |
| 429 | Three J Operating Company, Inc. | Jacksboro, TX 76458 | Oil & Gas Operator | Dec 2025 |
| 430 | Three J'S Petroleum, Inc. | Lubbock, TX 79423 | Oil & Gas Operator | Dec 2025 |
| 431 | Three Mile Joint Venture | Houston, TX 77027 | Oil & Gas Operator | Jul 1995 |
| 432 | Three P Operating Co.,GP, L.L.C. | Newcastle, TX 76372 | Oil & Gas Operator | Dec 2025 |
| 433 | Three P Operating Company | Newcastle, TX 76372 | Oil & Gas Operator | Nov 2007 |
| 434 | Three Point Energy L.L.C. | Atlanta, TX 75551 | Oil Operator | Dec 2025 |
| 435 | Three R Oil Company | Post, TX 79356 | Oil & Gas Operator | Dec 2025 |
| 436 | Three Rivers Oper Co III LLC | Austin, TX 78735 | Oil & Gas Operator | Nov 2017 |
| 437 | Three Rivers Operating Co II LLC | Austin, TX 78735 | Oil & Gas Operator | Mar 2017 |
| 438 | Three Rivers Operating Co LLC | Austin, TX 78735 | Oil & Gas Operator | Mar 2017 |
| 439 | Three Sisters Petroleum, Inc. | Oil City, LA 71061 | Oil & Gas Operator | Jan 2025 |
| 440 | Three Span Oil & Gas, Inc. | Midland, TX 79710 | Oil & Gas Operator | Dec 2025 |
| 441 | Three Summits Operating LLC | Grapevine, TX 76051 | Oil & Gas Operator | Dec 2025 |
| 442 | Three-B Oil Company, The | Monahans, TX 79756 | Oil & Gas Operator | Dec 2025 |
| 443 | Three-C Oil And Gas | Hebbronville, TX 78361 | Oil & Gas Operator | Dec 2025 |
| 444 | Three-C Production Company | Temple, TX 76502 | Oil Operator | Dec 2025 |
| 445 | Threeway Drilling Company | Midland, TX 79701 | Oil & Gas Operator | Jun 2025 |
| 446 | Thresher Energy, Inc. | Houston, TX 77060 | Oil & Gas Operator | Dec 2025 |
| 447 | Threshold Development Company | Fort Worth, TX 76109 | Oil & Gas Operator | Aug 2016 |
| 448 | Threshold Exploration, Inc. | College Sta, TX 77842 | Oil & Gas Operator | Oct 2015 |
| 449 | Thrifty Well Service | Rice, TX 75155 | Oil & Gas Operator | Jun 2009 |
| 450 | Throckmorton Oil, Inc. | Throckmorton, TX 76483 | Oil & Gas Operator | Mar 2008 |
| 451 | Throne Delaware Resources, LLC | McKinney, TX 75072 | Oil & Gas Operator | Dec 2021 |
| 452 | Throne Petroleum Resources LLC | Houston, TX 77006 | Oil & Gas Operator | Aug 2021 |
| 453 | THT Covenant Holdings, LLC | Wichita Falls, TX 76307 | Oil Operator | Dec 2025 |
| 454 | Thunder Oil & Gas, LLC | Ardmore, OK 73402 | Oil & Gas Operator | Sep 2025 |
| 455 | Thunder Resources LLC | Graham, TX 76450 | Oil Operator | Dec 2025 |
| 456 | Thunderbird (Texas) Resources LP | Edmond, OK 73025 | Oil & Gas Operator | Apr 2019 |
| 457 | Thunderbird Drilling, Inc. | Wichita, KS 67207 | Oil Operator | Oct 2008 |
| 458 | Thunderbird Energy, Inc. | Norman, OK 73069 | Oil & Gas Operator | Dec 2025 |
| 459 | Thunderbird Operating, L.L.C. | Graham, TX 76450 | Oil & Gas Operator | Dec 2025 |
| 460 | Thunderbolt Oil & Gas, Inc. | Abilene, TX 79605 | Oil & Gas Operator | Feb 2004 |
| 461 | Thunderbolt Petroleum Co. LLC | Midland, TX 79702 | Oil & Gas Operator | Apr 2011 |
| 462 | Thurston Texas Operating Co LLC | Dallas, TX 75219 | Oil Operator | Dec 2025 |
| 463 | Tiara Resources, Inc. | Fort Worth, TX 76179 | Oil & Gas Operator | Apr 1998 |
| 464 | Tiburon Oil & Gas, Inc. | Midland, TX 79701 | Oil & Gas Operator | Aug 2000 |
| 465 | Tice, Robin Alejandrina | Gordon, TX 76453 | Gas Operator | Dec 2025 |
| 466 | Tidal Petroleum, Inc. | Schertz, TX 78154 | Oil & Gas Operator | Dec 2025 |
| 467 | Tide Energy, Inc. | Dallas, TX 75206 | Gas Operator | Oct 1994 |
| 468 | Tide West Oil Company | Tulsa, OK 74136 | Oil & Gas Operator | Mar 2021 |
| 469 | Tidelands Gas Corporation | Flower Mound, TX 75028 | Oil & Gas Operator | Sep 2000 |
| 470 | Tidelands Oil Corporation | Crystal City, TX 78839 | Oil & Gas Operator | Aug 2003 |
| 471 | Tidemark Exploration Inc | Tulsa, OK 74120 | Oil & Gas Operator | Apr 2019 |
| 472 | Tidemark Petroleum, Inc. | San Antonio, TX 78209 | Oil & Gas Operator | Jul 2002 |
| 473 | Tidewater Minerals Corporation | Orange Grove, TX 78372 | Oil & Gas Operator | Dec 2025 |
| 474 | Tidewater Resources Corporation | Memphis, TN 38138 | Gas Operator | Feb 2025 |
| 475 | Tidlow | Santa Fe, NM 87508 | Oil & Gas Operator | Dec 2007 |
| 476 | Tidmore, Ann | Albany, TX 76430 | Oil & Gas Operator | Dec 2025 |
| 477 | Tidwell Production Company | Sonora, TX 76950 | Oil & Gas Operator | Dec 2025 |
| 478 | Tierra Mineral Development, L.C. | Dallas, TX 75244 | Oil & Gas Operator | Oct 1994 |
| 479 | Tiger Resources, L.L.C. | Houston, TX 77070 | Oil & Gas Operator | Feb 2004 |
| 480 | Tightrock Enterprises, Inc. | Trinidad, TX 75163 | Oil Operator | Dec 2025 |
| 481 | Tigrett, Robert L. Oil & Gas Co. | Pampa, TX 79065 | Oil & Gas Operator | Dec 2013 |
| 482 | Tiki Oil & Gas, LLC | Cisco, TX 76437 | Oil Operator | Dec 2025 |
| 483 | Tilley Oil & Gas, Inc. | Oklahoma City, OK 73172 | Oil & Gas Operator | Dec 2025 |
| 484 | Tillman, Jack Equipment Co. | Holliday, TX 76366 | Oil & Gas Operator | Sep 2004 |
| 485 | Tilmon Oil Co. | Luling, TX 78648 | Oil & Gas Operator | Sep 2012 |
| 486 | Timberwolf Energy, Inc. | Houston, TX 77042 | Oil & Gas Operator | Dec 2025 |
| 487 | Timn Oil Co. | Lubbock, TX 79424 | Oil & Gas Operator | Aug 1997 |
| 488 | Tindle Petroleum LLC | Midland, TX 79701 | Oil & Gas Operator | Jan 2023 |
| 489 | Tipco Operating Co. | Marshall, TX 75671 | Oil & Gas Operator | Dec 2025 |
| 490 | Tipperary Oil & Gas Corporation | Denver, CO 80202 | Oil & Gas Operator | May 2014 |
| 491 | Titan Allen Dome LLC | Houston, TX 77056 | Oil Operator | Feb 2015 |
| 492 | Titan Energy Operating LLC | Houston, TX 77056 | Oil Operator | Jan 2016 |
| 493 | Titan Energy, Inc. | Austin, TX 78703 | Oil & Gas Operator | Dec 2025 |
| 494 | Titan Exploration LLC | Denver, CO 80202 | Oil & Gas Operator | Oct 2025 |
| 495 | Titan Operating, LLC | Fort Worth, TX 76102 | Oil & Gas Operator | Jun 2012 |
| 496 | Titan Petroleum, Inc. | Tomball, TX 77375 | Oil & Gas Operator | Nov 2004 |
| 497 | Titan Resources I, Inc. | Midland, TX 79701 | Oil & Gas Operator | Jun 2000 |
| 498 | Titan Rock E&P, LLC | Kilgore, TX 75663 | Oil & Gas Operator | Jan 2024 |
| 499 | Titus Liberty Multi Well 2, LLC | Irving, TX 75063 | Oil & Gas Operator | Dec 2025 |
| 500 | Titus Oil & Gas Production, LLC | Fort Worth, TX 76102 | Oil & Gas Operator | Sep 2022 |