| 501 | Terrel Production Co | | Oil & Gas Operator | Dec 2024 |
| 502 | Terreland Corporation | Sunray, TX 79086 | Oil & Gas Operator | Oct 2004 |
| 503 | Terrell Oil & Gas Production Co. | Hamlin, TX 79520 | Oil & Gas Operator | Jun 2025 |
| 504 | Terrgin Oil & Gas LLC | Frazeysburg, OH 43822 | Oil & Gas Operator | Dec 2021 |
| 505 | Terrick Resources | Midland, TX 79708 | Oil & Gas Operator | Jul 2005 |
| 506 | Terrier Oil Company | | Oil & Gas Operator | Feb 2015 |
| 507 | Territory Resources LLC | Stillwater, OK 74074-1869 | Oil & Gas Operator | Apr 2025 |
| 508 | Terrol Energy In | | Oil Operator | Feb 1993 |
| 509 | Terrol Energy, Inc. | Hygiene, CO 80533 | Oil & Gas Operator | Dec 2006 |
| 510 | Terronne Petroleum Corporation | | Oil & Gas Operator | Nov 2024 |
| 511 | Terry D Coan | Youngsville, PA 16371-3608 | Oil & Gas Operator | Dec 2021 |
| 512 | Terry Development, Inc. | | Oil & Gas Operator | Aug 1992 |
| 513 | Terry Enterprises, Inc. | West Columbia, TX 77486 | Oil & Gas Operator | Jun 2025 |
| 514 | Terry Jack | Konawa, OK 74849-0337 | Oil Operator | Feb 2012 |
| 515 | Terry John Trust | Aurora, CO 80012-5112 | Oil & Gas Operator | May 2016 |
| 516 | Terry Oil Company LLC | | Oil Operator | Dec 2024 |
| 517 | Terry Pate | Hobbs, NM 88240 | Oil & Gas Operator | Jun 2006 |
| 518 | Terry Petroleum Company | Houston, TX 77270 | Oil & Gas Operator | Dec 1997 |
| 519 | Terry Production Co | Stroud, OK 74079-0475 | Oil & Gas Operator | Aug 2008 |
| 520 | Terry Sims & Associates, Inc. | | Oil Operator | Sep 2009 |
| 521 | Terry'S Roustabout Service, Inc. | Throckmorton, TX 76483 | Oil & Gas Operator | Oct 2002 |
| 522 | Terry, Lewis D. | Olney, TX 76374 | Oil & Gas Operator | Sep 1995 |
| 523 | Terry, R. K. | West Columbia, TX 77486 | Oil & Gas Operator | Jun 2025 |
| 524 | Tervita, LLC | | Oil Operator | May 2021 |
| 525 | Terzan Energy II LLC | Chandler, OK 74834 | Oil & Gas Operator | Feb 2025 |
| 526 | Tesla Resources, Inc. | | Oil & Gas Operator | Aug 1996 |
| 527 | Tesoro E&P Company, L.P. | San Antonio, TX 78216 | Oil & Gas Operator | Jan 2000 |
| 528 | Tesoro Expl. & Prod. Company | San Antonio, TX 78216 | Gas Operator | Sep 2010 |
| 529 | Tesoro Petroleum | | Oil Operator | Mar 1982 |
| 530 | Tesoro Petroleum Corporation | | Oil & Gas Operator | May 1982 |
| 531 | Tess Oil Company | Borger, TX 79008 | Oil & Gas Operator | Mar 2008 |
| 532 | Tessara Petroleum Resources, LLC | Houston, TX 77086 | Oil & Gas Operator | Apr 2020 |
| 533 | Tessera Energy LLC | Oklahoma City, OK 73120 | Oil & Gas Operator | Feb 2025 |
| 534 | Testco Production Company | Watonga, OK 73772-0589 | Oil & Gas Operator | Aug 2013 |
| 535 | Tesuque Oil & Gas LLC | Rockdale, TX 76567 | Oil Operator | Jun 2025 |
| 536 | Tet Energy | | Oil Operator | Feb 2025 |
| 537 | Teton Energy Co Inc | Denver, CO 80239 | Oil Operator | Dec 1983 |
| 538 | Teton Petroleum Corporation | Kerrville, TX 78028 | Oil & Gas Operator | Jun 2025 |
| 539 | Tetra Oil Company | | Oil & Gas Operator | Mar 2025 |
| 540 | Tetragon Investments, LLC | Abilene, TX 79604 | Oil Operator | Jul 2014 |
| 541 | Tettleton, Jon Otis | Nocona, TX 76255 | Oil & Gas Operator | Aug 2003 |
| 542 | Tettleton, Steven B. | Nocona, TX 76255 | Oil Operator | Jun 2025 |
| 543 | Tevebaugh MGMT Co | Baden, PA 15005-0123 | Oil & Gas Operator | Dec 2002 |
| 544 | Tex-Am Petroleum Corp. | Eastland, TX 76448 | Oil & Gas Operator | Jun 2025 |
| 545 | Tex-Am-Energy Inc. | Dallas, TX 75205 | Oil & Gas Operator | Mar 2008 |
| 546 | Tex-Ann Oil & Gas Services, Inc. | Abilene, TX 79608 | Oil & Gas Operator | Jun 2025 |
| 547 | Tex-Atic Resources, Inc. | S. Lake Tahoe, CA 96150 | Oil & Gas Operator | Jun 2025 |
| 548 | Tex-Con-Brehm-Basin Expl. | | Oil & Gas Operator | May 1990 |
| 549 | Tex-Hio Energy | Terrell, TX 75156 | Oil & Gas Operator | Dec 1997 |
| 550 | Tex-Lee Operating Company | Giddings, TX 78942 | Oil & Gas Operator | Jun 2025 |
| 551 | Tex-Oak, Inc. | Oklahoma City, OK 73155 | Oil & Gas Operator | Dec 1995 |
| 552 | Tex-Ok Energy LP | Cody, WY 82414 | Oil & Gas Operator | Mar 2025 |
| 553 | Tex-Ok Energy, LTD Partnership | Cody, WY 82414 | Oil & Gas Operator | Jun 2025 |
| 554 | Tex-R Energy, Inc. | Abilene, TX 79608 | Oil & Gas Operator | Feb 2021 |
| 555 | Tex-Star Production | Dallas, TX 75206 | Oil & Gas Operator | Mar 2025 |
| 556 | Tex-Well Oil & Gas Corp. | Pampa, TX 79066 | Oil & Gas Operator | Aug 2003 |
| 557 | Tex/Con Oil & Gas Company | Houston, TX 77074 | Oil & Gas Operator | Feb 2001 |
| 558 | Texacal, Inc. | Newport Beach, CA 92660 | Oil & Gas Operator | Jun 2025 |
| 559 | Texaco E & P Inc | Houston, TX 77099 | Oil & Gas Operator | Jun 2025 |
| 560 | Texaco Expl. And Prod. Inc. | Houston, TX 77236 | Oil & Gas Operator | Mar 2025 |
| 561 | Texaco Explorati | | Oil & Gas Operator | Dec 1996 |
| 562 | Texaco Exploration & Prod | Midland, TX 79702 | Oil & Gas Operator | Aug 2002 |
| 563 | Texaco Exploration & Production Inc N W | Farmington, NM 87401 | Oil & Gas Operator | Aug 1995 |
| 564 | Texaco Inc | Kingfisher, OK 73750 | Oil & Gas Operator | Dec 2017 |
| 565 | Texaco Inc & A.C. Glassell Jr | | Oil & Gas Operator | Aug 1980 |
| 566 | Texaco Oils, Inc. | Tulsa, OK 74102-2420 | Oil & Gas Operator | Jan 2003 |
| 567 | Texaco Producing Inc. | Rock Springs, WY 82901 | Oil & Gas Operator | Dec 2000 |
| 568 | Texaco Seaboard, Inc. | | Gas Operator | Sep 1980 |
| 569 | Texaco USA - Mor | | Oil Operator | Aug 1988 |
| 570 | Texada Resources, Inc. | | Oil & Gas Operator | Dec 1992 |
| 571 | Texakoma E & P, LLC | Plano, TX 75024 | Oil & Gas Operator | Jun 2025 |
| 572 | Texakoma Exploration & Production LLC | Plano, TX 75024 | Oil & Gas Operator | Mar 2025 |
| 573 | Texakoma Oil & Gas Corp | Dallas, TX 75240 | Oil & Gas Operator | Sep 2014 |
| 574 | Texakoma Operating, L.P. | Plano, TX 75024 | Oil & Gas Operator | Jan 2025 |
| 575 | Texakoma Opr LP | Plano, TX 75024-6679 | Oil & Gas Operator | Dec 2012 |
| 576 | Texakota | | Oil & Gas Operator | Mar 1995 |
| 577 | Texakota, Inc. | Houston, TX 77098 | Oil & Gas Operator | Mar 2021 |
| 578 | Texalta Oil And Gas Inc. | | Gas Operator | Dec 1990 |
| 579 | Texan Petroleum Corporation | Dallas, TX 75204 | Oil & Gas Operator | Oct 2004 |
| 580 | Texan Production | Pearsall, TX 78061 | Oil & Gas Operator | Aug 2003 |
| 581 | Texan Production Company, Inc. | Canyon Lake, TX 78133 | Oil & Gas Operator | Jun 2025 |
| 582 | Texana Operating Company | Houston, TX 77090 | Oil & Gas Operator | Jun 2025 |
| 583 | Texas American Oil Corporation | Midland, TX 79701 | Oil & Gas Operator | Jan 2001 |
| 584 | Texas American Resources Company | Austin, TX 78701 | Oil & Gas Operator | Jun 2025 |
| 585 | Texas City Refining, Inc. | | Oil & Gas Operator | Nov 1988 |
| 586 | Texas Coastal Resources LLC | Fairhope, AL 36532 | Oil Operator | Jun 2025 |
| 587 | Texas Concho Operating Co. | Eldorado, TX 76936 | Oil & Gas Operator | Mar 1999 |
| 588 | Texas Consolidated Pet. Corp. | Fort Worth, TX 76109 | Oil & Gas Operator | Jun 2025 |
| 589 | Texas Crude & Dale Gas Expl | | Oil & Gas Operator | Dec 1984 |
| 590 | Texas Crude Energy, Inc. | Houston, TX 77256 | Oil & Gas Operator | Oct 2012 |
| 591 | Texas Crude Exploration, Inc. | Fort Worth, TX 76116 | Oil & Gas Operator | Aug 1992 |
| 592 | Texas Crude Oil Co. | | Oil & Gas Operator | Dec 1984 |
| 593 | Texas Crude Oil Co. Et Al | | Oil & Gas Operator | May 1992 |
| 594 | Texas Crude Oil, Inc. | | Oil & Gas Operator | Dec 1984 |
| 595 | Texas Crude Operator, Inc. | Houston, TX 77098 | Oil & Gas Operator | Aug 2017 |
| 596 | Texas Crude, Inc. | Houston, TX 77256 | Oil & Gas Operator | Oct 1995 |
| 597 | Texas Crude-Rebstock & Reeves | | Oil & Gas Operator | Feb 1980 |
| 598 | Texas Crude-Wainoco-Hilliard | | Oil & Gas Operator | Jul 1978 |
| 599 | Texas Eastern Skyline Oil | Houston, TX 77252 | Oil & Gas Operator | Jan 1987 |
| 600 | Texas Eastern Transm. Corp. | | Oil & Gas Operator | Dec 2002 |