| 4601 | Trade & Development Corp | | Oil & Gas Operator | Nov 1996 |
| 4602 | Tradestar Energy, Inc. | Hot Springs, AR 71913 | Oil Operator | Feb 2021 |
| 4603 | Tradition Resources Oper, LLC | Houston, TX 77002 | Oil & Gas Operator | Jul 2017 |
| 4604 | Trafalgar House Oil & Gas Inc | Houston, TX 77002-7346 | Oil & Gas Operator | Jan 1992 |
| 4605 | Traillour Oil Co. | | Oil & Gas Operator | Mar 1990 |
| 4606 | Trans Ocean Oil, Inc. | | Oil & Gas Operator | Sep 1980 |
| 4607 | Trans-Gulf Petroleum Corp | | Oil & Gas Operator | Sep 1999 |
| 4608 | Trans-Pacific Oil & Gas Inc. | | Oil & Gas Operator | Mar 1982 |
| 4609 | Trans-Sabine Pipeline Corp | | Oil Operator | Mar 2009 |
| 4610 | Trans-Western Exploration Inc | Dallas, TX 75240 | Oil & Gas Operator | Mar 1993 |
| 4611 | Transamerican Energy/Toce Oil | | Oil & Gas Operator | Dec 1994 |
| 4612 | Transamerican-Swepi-Toce Oil | | Oil & Gas Operator | Apr 1990 |
| 4613 | Transco Exploration Company | | Oil & Gas Operator | Jul 1989 |
| 4614 | Transcontinental Gas P/L Corp. | | Oil & Gas Operator | Dec 2009 |
| 4615 | Transcontinental Gas Pipeline Co LLC | | Oil Operator | Jan 2025 |
| 4616 | Transcontinental Oil Corp. | | Oil & Gas Operator | Sep 1985 |
| 4617 | Transfuel Resources Co | Houston, TX 77215 | Oil & Gas Operator | Aug 2013 |
| 4618 | Transtexas Gas Corporation | Houston, TX 77265 | Oil & Gas Operator | Aug 2005 |
| 4619 | Transworld Expl. & Prod., Inc. | | Oil & Gas Operator | Mar 2004 |
| 4620 | Traver Oil & Gas Corporation | | Oil & Gas Operator | Sep 2000 |
| 4621 | Traver Oil Company | | Oil & Gas Operator | Sep 2000 |
| 4622 | Traver-Patterson Petroleum Inc | | Oil & Gas Operator | May 1990 |
| 4623 | Travis E. Duren | | Oil Operator | Jul 1995 |
| 4624 | Trebole Operating Company | | Oil Operator | Jul 1979 |
| 4625 | Tredegar Properties, Inc. | | Oil Operator | Jun 1990 |
| 4626 | Trek Resources, Inc. | Dallas, TX 75207 | Oil & Gas Operator | May 2026 |
| 4627 | Trendsetter Production Co, Inc | | Oil & Gas Operator | Jul 2008 |
| 4628 | Tri Investment Company | | Oil Operator | Mar 1980 |
| 4629 | Tri-C Resources, Inc. | Houston, TX 77024 | Oil & Gas Operator | Aug 2009 |
| 4630 | Tri-C Resources, LLC | Houston, TX 77024 | Oil & Gas Operator | May 2026 |
| 4631 | Tri-Par Exploration, Inc. | | Oil Operator | Oct 2001 |
| 4632 | Tri-Production Company | | Oil Operator | Apr 1994 |
| 4633 | Tri-State Exploration & Prod Inc | Marshall, TX 75671 | Oil & Gas Operator | Aug 2003 |
| 4634 | Tri-State Sales & Production | Rodessa, LA 71069 | Oil & Gas Operator | Dec 2008 |
| 4635 | Tri-Union Development Corp. | Houston, TX 77002 | Oil & Gas Operator | May 2026 |
| 4636 | Triad Energy Corp Of Texas | Houston, TX 77057-2696 | Oil & Gas Operator | Sep 2014 |
| 4637 | Triad Resources Inc | Spring, TX 77389 | Oil & Gas Operator | Dec 2020 |
| 4638 | Triangle Oil & G G Cornwell | | Oil & Gas Operator | Nov 1981 |
| 4639 | Triangle Oil Of Hosston | | Oil Operator | Jul 2014 |
| 4640 | Triangle Oil Producers Inc | | Oil & Gas Operator | Jun 1998 |
| 4641 | Tribal Oil Company | | Oil & Gas Operator | Dec 1981 |
| 4642 | Tricentrol Resources Inc | Englewood, CO 80111 | Oil & Gas Operator | Jun 1984 |
| 4643 | Trich Production, Inc. | Longview, TX 75606 | Oil & Gas Operator | Jan 2025 |
| 4644 | Trichel Contracting Company | | Oil & Gas Operator | Sep 1987 |
| 4645 | Trickle Down Oil, Inc. | | Oil & Gas Operator | Feb 2016 |
| 4646 | Trico Energy Corporation | | Oil Operator | May 1984 |
| 4647 | Trico Oil & Gas Inc. | Kilgore, TX 75662 | Oil & Gas Operator | May 2026 |
| 4648 | Trident Oil & Gas Corp. | | Oil & Gas Operator | Sep 2000 |
| 4649 | Trigon Exploration, Inc. | | Oil & Gas Operator | Jan 1999 |
| 4650 | Trinidad Petroleum Corporation | | Oil & Gas Operator | Apr 1990 |
| 4651 | Trinity Operating (Usg), LLC | Houston, TX 77002 | Oil & Gas Operator | May 2026 |
| 4652 | Trinity Resources, Inc. | Houston, TX 77277 | Oil & Gas Operator | May 2020 |
| 4653 | Trinity River Energy Oper, LLC | Houston, TX 77008 | Oil & Gas Operator | May 2018 |
| 4654 | Triple J Investments Inc | Longview, TX 75606 | Oil & Gas Operator | Feb 2023 |
| 4655 | Triple J Oil Co. | Pampa, TX 79065 | Oil & Gas Operator | Aug 1996 |
| 4656 | Triple L Oil Company | Corpus Christ, TX 78469 | Oil & Gas Operator | Jan 1998 |
| 4657 | Triple L Operating Company LLC | Kilgore, TX 75663 | Oil Operator | May 2026 |
| 4658 | Triple S Oil Company | | Oil & Gas Operator | Feb 1979 |
| 4659 | Tripower Resources, Inc. | Ardmore, OK 73402 | Oil & Gas Operator | Mar 2020 |
| 4660 | Tristar Energy 1 | | Oil Operator | Sep 1987 |
| 4661 | Tristate Nla, LLC | | Oil Operator | Dec 2024 |
| 4662 | Triton Oil & Gas Corp. | Houston, TX 77002 | Oil & Gas Operator | Nov 2014 |
| 4663 | Triumph Energy Inc | Lafayette, LA 70505 | Oil & Gas Operator | Nov 2015 |
| 4664 | Triumph Energy Inc-P B Berry | | Oil & Gas Operator | Jun 1986 |
| 4665 | Troy E. Boyd | | Oil Operator | Oct 1998 |
| 4666 | Trunkline Gas Company | | Oil Operator | Mar 2008 |
| 4667 | Tryvest, Inc. | | Oil & Gas Operator | Sep 1991 |
| 4668 | Tucker Operating Co., Inc. | Victoria, TX 77903 | Oil & Gas Operator | May 2026 |
| 4669 | Tulip Industries, Inc. | | Oil & Gas Operator | Feb 2024 |
| 4670 | Tundra Energy | | Oil Operator | Jan 2025 |
| 4671 | Tundra Operating LLC | Spring, TX 77386 | Oil Operator | May 2017 |
| 4672 | Turnkey E&P Corporation | | Oil & Gas Operator | Dec 2010 |
| 4673 | TWC Oil Company, Inc. | | Oil Operator | Jan 2025 |
| 4674 | Twin City Gas | | Gas Operator | Nov 1997 |
| 4675 | Twiner Oil & Gas Corporation | | Oil & Gas Operator | Oct 1988 |
| 4676 | Two Bayous, Inc. | | Oil & Gas Operator | Dec 2024 |
| 4677 | Txla Energy, Inc. | Houston, TX 77018 | Oil & Gas Operator | May 2026 |
| 4678 | Txo Prod Corp.-Arkla Expl. Co. | | Oil & Gas Operator | Dec 1990 |
| 4679 | Txo Production Corp. | Ganado, TX 77962 | Oil & Gas Operator | Aug 2022 |
| 4680 | Txo Production Corp/Amh O&G Co | | Oil & Gas Operator | Dec 1990 |
| 4681 | TXP Operating Co. | | Oil & Gas Operator | Jul 1992 |
| 4682 | TXX Operating LLC | Shreveport, LA 71133 | Oil & Gas Operator | May 2026 |
| 4683 | Ty-Tex Exploration, Inc. | Tyler, TX 75711 | Oil Operator | Dec 2000 |
| 4684 | Tygr Operating Company, LLC | | Oil & Gas Operator | Nov 2024 |
| 4685 | Tyler Production, LLC | | Oil & Gas Operator | Jul 2013 |
| 4686 | Tysco Oil And Gas Corp. | | Oil & Gas Operator | Dec 2024 |
| 4687 | Tyson Oil Co. | | Oil Operator | Jan 2025 |
| 4688 | U R C C | | Oil & Gas Operator | Jun 1991 |
| 4689 | U S Exploraton Liq Trust | | Oil & Gas Operator | Oct 1994 |
| 4690 | U S Liquids Of La., L.P. | | Oil Operator | Apr 2014 |
| 4691 | U. D. Man, Inc. | San Antonio, TX 78212 | Oil & Gas Operator | May 2026 |
| 4692 | U. O. C., Inc. | | Oil Operator | Jun 2019 |
| 4693 | U. S. Operating, Inc. | Dallas, TX 75252 | Oil & Gas Operator | Jul 2025 |
| 4694 | U.S. Capital Corp Of Am, Inc. | | Oil & Gas Operator | Aug 1998 |
| 4695 | U.S. Exploration Company | Houston, TX 77002 | Oil & Gas Operator | Aug 2003 |
| 4696 | Ultramar Oil & Gas LTD | Houston, TX 77060 | Oil & Gas Operator | Jul 1995 |
| 4697 | Ultramar Production Company | | Oil & Gas Operator | Dec 1991 |
| 4698 | Umc Petroleum Corporation | Houston, TX 77002 | Oil & Gas Operator | Mar 2015 |
| 4699 | Uni Production Company, Inc. | | Oil & Gas Operator | Apr 1988 |
| 4700 | Unifid Oil & Gas Corp. | | Oil & Gas Operator | Mar 1994 |