| 401 | Tej Ventures | | Oil & Gas Operator | Dec 2002 |
| 402 | Tejas Gas Corp | | Oil & Gas Operator | Dec 1974 |
| 403 | Tejas Gas Pipeline Company | Houston, TX 77010 | Oil & Gas Operator | Apr 1998 |
| 404 | Tejas Gas Pipeline, L.P. | Houston, TX 77002 | Oil & Gas Operator | Feb 2002 |
| 405 | Tejas Jack Sales, Inc. | Big Lake, TX 76932 | Oil & Gas Operator | Jul 2025 |
| 406 | Tejas Operating Company, Inc. | Houston, TX 77257 | Oil & Gas Operator | May 1995 |
| 407 | Tejas Operating LLC | Houston, TX 77056 | Oil & Gas Operator | Jul 2025 |
| 408 | Tejas Operators, Inc. | Midland, TX 79702 | Oil & Gas Operator | Aug 2003 |
| 409 | Tejas Permian Operating, LLC | Midland, TX 79702 | Oil & Gas Operator | Jul 2025 |
| 410 | Tejas Petroleum Resources, LLC | Aubrey, TX 76227 | Oil & Gas Operator | Jul 2025 |
| 411 | Tejas Production Company | | Oil Operator | Nov 1979 |
| 412 | Tejas Trucking, Inc. | Andrews, TX 79714 | Oil & Gas Operator | Jul 2025 |
| 413 | Tejas Western Corp. | Granbury, TX 76048 | Oil & Gas Operator | Jul 2018 |
| 414 | Tejones Operating Corporation | San Antonio, TX 78217 | Oil & Gas Operator | Jul 2025 |
| 415 | Teke Production LLC | Houston, TX 77269 | Oil Operator | Jul 2025 |
| 416 | Tekenergy, Inc. | Oklahoma City, OK 73112 | Oil & Gas Operator | Mar 2015 |
| 417 | Tekna Synergy Corporation | Midland, TX 79702 | Oil & Gas Operator | Jul 2025 |
| 418 | Teko Oil & Gas I | | Oil Operator | Aug 1992 |
| 419 | Teleo Operating, LLC | Dallas, TX 75219 | Oil & Gas Operator | Apr 2009 |
| 420 | Telesis Operating Co. | Fort Worth, TX 76116 | Oil & Gas Operator | Jul 2025 |
| 421 | Telico Minerals, L.L.C. | | Oil & Gas Operator | Oct 2019 |
| 422 | Tellurian Operating LLC | | Oil & Gas Operator | Jun 2024 |
| 423 | Tellus Energy, LLC | | Oil & Gas Operator | Dec 2024 |
| 424 | Tellus Operating Group, LLC | | Oil & Gas Operator | Apr 2025 |
| 425 | Tema Oil And Gas Company | Houston, TX 77084 | Oil & Gas Operator | Jul 2025 |
| 426 | Tema Oil And Gas, LLC | Houston, TX 77040 | Oil & Gas Operator | Apr 2000 |
| 427 | Tema Oil Company | Amarillo, TX 79101 | Oil & Gas Operator | Jun 2009 |
| 428 | Temagami Oil & Gas LTD | | Oil & Gas Operator | May 2007 |
| 429 | Tember Oil Company | Holliday, TX 76366 | Oil & Gas Operator | Jul 2025 |
| 430 | Temblor Petroleum Co. LLC | | Oil & Gas Operator | Apr 2025 |
| 431 | Temescal Resources LLC | | Oil & Gas Operator | May 2025 |
| 432 | Temex Energy, Inc. | Oklahoma City, OK 73101 | Oil & Gas Operator | Feb 2002 |
| 433 | Tempel Contracting, Inc. | Joplin, MT 59531 | Gas Operator | Feb 2025 |
| 434 | Tempest Energy Resources, LP | Houston, TX 77251 | Oil & Gas Operator | Jun 2013 |
| 435 | Tempest Oil Company, Inc. | | Oil & Gas Operator | Jul 1978 |
| 436 | Templar Operating LLC | Oklahoma City, OK 73142 | Oil & Gas Operator | Apr 2025 |
| 437 | Temple Oil & Gas Co | Crooksville, OH 43731 | Oil & Gas Operator | Dec 2024 |
| 438 | Temple Oil Co | | Oil & Gas Operator | Oct 1992 |
| 439 | Temple Resources LLC | | Oil Operator | Apr 2025 |
| 440 | Templeton Energy Inc | | Oil & Gas Operator | Jul 1987 |
| 441 | Templeton Oil, Inc. | Houston, TX 77002 | Oil & Gas Operator | Nov 1994 |
| 442 | Tempo Energy, Inc. | Midland, TX 79702 | Oil & Gas Operator | Jul 2025 |
| 443 | Tempo Resources GP, LLC | Mineral Wells, TX 76068 | Oil & Gas Operator | Apr 2013 |
| 444 | Ten A Coal Company | Bridgeport, WV 26330 | Oil & Gas Operator | Dec 2020 |
| 445 | Ten Grand Energy Company Inc | Nachogdoches, TX 75963-1880 | Oil Operator | Mar 2011 |
| 446 | Tenaska Res LLC | Canonsburg, PA 15317 | Gas Operator | May 2020 |
| 447 | Tend Oil Inc. | Tyler, TX 75703 | Oil & Gas Operator | Jul 1995 |
| 448 | Tender Equity Corporation | Marietta, OH 45750 | Oil & Gas Operator | Dec 2007 |
| 449 | Tenex Corporation | Houston, TX 77227 | Oil & Gas Operator | Dec 2007 |
| 450 | Tenex Oil Corpor | | Oil Operator | May 1991 |
| 451 | Tenexco Inc | Oakbrook Terrace, IL 60181 | Gas Operator | Dec 1998 |
| 452 | Tengasco, Inc. | Houston, TX 77063 | Oil & Gas Operator | Apr 2024 |
| 453 | Tenison Oil Comp | | Oil Operator | Jan 1993 |
| 454 | Tenison Oil Company | Abilene, TX 79605 | Oil & Gas Operator | Jul 2025 |
| 455 | Tenk, Lawrence O. | Ottawa, KS 66067 | Oil & Gas Operator | Oct 1998 |
| 456 | Tenmile Land Limited Liability Company | Bridgeport, WV 26330 | Oil & Gas Operator | Dec 2021 |
| 457 | Tenneco Inc. | | Oil & Gas Operator | Jun 1989 |
| 458 | Tenneco Oil Comp | | Oil & Gas Operator | Aug 1995 |
| 459 | Tenneco Oil Company | Oklahoma City, OK 73125 | Oil & Gas Operator | Apr 2025 |
| 460 | Tenneco Ventures Corporation | | Oil & Gas Operator | Feb 1996 |
| 461 | Tenneco West, Inc. | | Oil & Gas Operator | Dec 1983 |
| 462 | Tennessee Gas Pipeline Company | | Oil & Gas Operator | Dec 2011 |
| 463 | Tennessee Gas Pipeline Company, LLC | Houston, TX 77002 | Oil Operator | Dec 2024 |
| 464 | Tennessee Properties, Inc | | Oil Operator | Dec 2014 |
| 465 | Tennyson Oil & Gas | Muskogee, OK 74401 | Oil Operator | Apr 2025 |
| 466 | Tenpas, Bruce | Clymer, NY 14724 | Gas Operator | Dec 2024 |
| 467 | Tensas Delta Expl Co., LLC | Shreveport, LA 71101-5323 | Oil & Gas Operator | Jul 2021 |
| 468 | Tensas Delta Explo. Co., LLC | Shreveport, LA 71101 | Oil & Gas Operator | Dec 2011 |
| 469 | Tensas Delta Land Company | | Oil & Gas Operator | Apr 2002 |
| 470 | Tensas Exploraton & Production Co LLC | | Oil & Gas Operator | Nov 2009 |
| 471 | Teocali Energy LLC | Denver, CO 80202 | Oil & Gas Operator | Jun 2025 |
| 472 | Teocalli Exploration LLC | Oklahoma City, OK 73118 | Oil & Gas Operator | May 2025 |
| 473 | Teon Management, LLC | Midland, TX 79704 | Oil & Gas Operator | Mar 2020 |
| 474 | Tep Barnett USA, LLC | Fort Worth, TX 76102 | Oil & Gas Operator | Jul 2025 |
| 475 | Tepco Resources, Inc. | Houston, TX 77027 | Oil & Gas Operator | Sep 2004 |
| 476 | Tepco, Inc. | Houston, TX 77002 | Oil & Gas Operator | Oct 1999 |
| 477 | Tepee Petroleum Company, Inc. | Houston, TX 77098 | Oil & Gas Operator | Feb 2014 |
| 478 | Ter Ex Inc | Butler, PA 16002-8638 | Gas Operator | Dec 1994 |
| 479 | Terex Energy Corporation | Casper, WY 82602 | Oil & Gas Operator | Aug 2019 |
| 480 | Terhune Harry C | Bartlesville, OK 74003 | Oil Operator | Feb 1997 |
| 481 | Terhune Opal S | Bartlesville, OK 74006-0472 | Oil Operator | Apr 2025 |
| 482 | Term Energy Corp. | Harrisville, WV 26362-0000 | Oil & Gas Operator | Dec 2021 |
| 483 | Termo Co. Of Texas | | Oil & Gas Operator | Dec 1986 |
| 484 | Terra Energy Co LLC | | Oil & Gas Operator | Apr 2018 |
| 485 | Terra Energy LTD | | Oil & Gas Operator | Apr 2018 |
| 486 | Terra Energy LTD And Miller Energy Inc And Mille | | Gas Operator | Dec 1998 |
| 487 | Terra Exploration & Production Co. Inc. | | Oil & Gas Operator | Dec 2009 |
| 488 | Terra Locus Services | Seguin, TX 78155 | Oil & Gas Operator | Jun 2000 |
| 489 | Terra Max Energy | | Oil Operator | Mar 1986 |
| 490 | Terra Production Company | Okemah, OK 74859-5924 | Oil & Gas Operator | Apr 2020 |
| 491 | Terra Resc Incor | | Oil Operator | Mar 1986 |
| 492 | Terra Resources, Inc. | Casper, WY 82601 | Oil & Gas Operator | Jun 1990 |
| 493 | Terrace Petroleum Corporation | Midland, TX 79701 | Oil & Gas Operator | Jul 2013 |
| 494 | Terrafina Energy, LLC | San Antonio, TX 78280 | Oil & Gas Operator | Jul 2025 |
| 495 | Terral D Hinds | | Oil Operator | Mar 2012 |
| 496 | Terrapet Corporation | | Oil & Gas Operator | Jun 2011 |
| 497 | Terrapin Energy LLC | Okmulgee, OK 74447 | Oil Operator | May 2025 |
| 498 | Terraquest Corporation | Edmond, OK 73034 | Oil & Gas Operator | Jul 1997 |
| 499 | Terrascan Drilling Corp | Dublin, OH 43017 | Oil Operator | Dec 2005 |
| 500 | Terrel Production Co | | Oil & Gas Operator | May 2025 |