| 1 | T & T Production Co. | Victoria, TX 77902 | Oil & Gas Operator | Feb 1995 |
| 2 | T&T Energy LLC | Wooster, OH 44691 | Oil & Gas Operator | Dec 2024 |
| 3 | Tandem Energy Corporation | Houston, TX 77056 | Oil & Gas Operator | Feb 2026 |
| 4 | Taos Resources Operating Co LLC | Houston, TX 77037 | Oil & Gas Operator | Dec 2019 |
| 5 | TDC Engineering, Inc. | Abilene, TX 79604 | Oil & Gas Operator | Feb 2026 |
| 6 | Technical Energy Services, Inc. | Norman, OK 73070 | Oil & Gas Operator | Nov 2025 |
| 7 | Tex-Lee Operating Company | Giddings, TX 78942 | Oil & Gas Operator | Feb 2026 |
| 8 | Texaco E & P Inc. | Houston, TX 77099 | Oil & Gas Operator | Feb 2026 |
| 9 | Texakoma Oil & Gas Corp | Dallas, TX 75240 | Oil & Gas Operator | Sep 2014 |
| 10 | Texas American Resources Company | Austin, TX 78701 | Oil & Gas Operator | Feb 2026 |
| 11 | Texas Gulf Gas Corporation | Fayetteville, TX 78940 | Oil & Gas Operator | Jun 2005 |
| 12 | Texas Independent Explor., Inc. | Houston, TX 77002 | Oil & Gas Operator | Oct 2002 |
| 13 | Texas Land & Trading Co, Inc. | Austin, TX 78734 | Oil & Gas Operator | Mar 2008 |
| 14 | Texas Onshore Energy, Inc. | Austin, TX 78704 | Oil & Gas Operator | Feb 2026 |
| 15 | Texas Vanguard Oil Company | Austin, TX 78720 | Oil & Gas Operator | Jan 2014 |
| 16 | Tgo Operating, LLC | Midland, TX 79705 | Oil & Gas Operator | Dec 2008 |
| 17 | Three Forks Operating Co, LLC | Flatonia, TX 78941 | Oil & Gas Operator | Feb 2026 |
| 18 | Tomlinson, Thomas K. Inc. | Port Lavaca, TX 77979 | Oil & Gas Operator | Jul 2003 |
| 19 | Tor Energy, LLC | Temple, TX 76501 | Oil & Gas Operator | Feb 2026 |
| 20 | Torch Operating Company | Houston, TX 77010 | Oil & Gas Operator | Mar 2015 |
| 21 | Total Minatome Corporation | Houston, TX 77210 | Oil & Gas Operator | Dec 1998 |
| 22 | Tracy Co. | Rockdale, TX 76567 | Oil & Gas Operator | Mar 2022 |
| 23 | Tracy Operating Co., LLC | Rockdale, TX 76567 | Oil & Gas Operator | Feb 2026 |
| 24 | Tradition Resources Oper, LLC | Houston, TX 77002 | Oil & Gas Operator | Jul 2017 |
| 25 | Trailblazer Energy Resources, LLC | Tulsa, OK 74136 | Oil & Gas Operator | Feb 2026 |
| 26 | Trans-Tex Operating LLC | Dallas, TX 75367 | Oil & Gas Operator | Feb 2026 |
| 27 | Treadstone Energy PRTNR Op, LLC | Katy, TX 77494 | Oil & Gas Operator | Feb 2026 |
| 28 | Trek Resources, Inc. | Dallas, TX 75207 | Oil & Gas Operator | Feb 2026 |
| 29 | Tri-C Resources, Inc. | Houston, TX 77024 | Oil & Gas Operator | Aug 2009 |
| 30 | Trinity Resources, Inc. | Houston, TX 77277 | Oil & Gas Operator | May 2020 |
| 31 | Triple "S" Resources Inc | Sapulpa, OK 74066 | Oil & Gas Operator | Jun 1995 |
| 32 | Trivista Operating LLC | Giddings, TX 78942 | Oil & Gas Operator | Feb 2026 |
| 33 | TT Operating, LLC | Kilgore, TX 75663 | Oil & Gas Operator | Feb 2026 |