| 1 | Tandem Energy Corporation | Houston, TX 77056 | Oil & Gas Operator | May 2025 |
| 2 | Targa Midstream Services LLC | Houston, TX 77002 | Oil Operator | Mar 2023 |
| 3 | TBM Catarina, LLC | Fort Worth, TX 76102 | Oil & Gas Operator | May 2025 |
| 4 | Teal Operating, LLC | Dallas, TX 75225 | Oil & Gas Operator | Oct 2021 |
| 5 | Tech Resources, Inc. | Georgetown, TX 78628 | Oil & Gas Operator | Dec 2001 |
| 6 | Texas American Resources Company | Austin, TX 78701 | Oil & Gas Operator | May 2025 |
| 7 | Texas Royalty Corp. | Austin, TX 78746 | Oil & Gas Operator | May 2025 |
| 8 | Texas Secondary Oil Corporation | Devine, TX 78016 | Oil & Gas Operator | May 2025 |
| 9 | Texas Southern Petroleum Corp. | Corpus Chrsti, TX 78410 | Oil & Gas Operator | May 2025 |
| 10 | Texas-Ohio Producing Company | Spring, TX 77383 | Oil & Gas Operator | Jul 1995 |
| 11 | Texican Crude & Hydrocarbons LLC | Houston, TX 77002 | Oil Operator | Sep 2023 |
| 12 | Thalmann Oilfield | Carrizo SPGS, TX 78834 | Oil Operator | May 2025 |
| 13 | Thomas Exploration & Devel., Inc | Jourdanton, TX 78026 | Oil & Gas Operator | May 2025 |
| 14 | Three Forks Operating Co, LLC | Flatonia, TX 78941 | Oil & Gas Operator | May 2025 |
| 15 | Three J Energy, Inc. | Seguin, TX 78155 | Oil & Gas Operator | May 2025 |
| 16 | Tidal Petroleum, Inc. | Schertz, TX 78154 | Oil & Gas Operator | May 2025 |
| 17 | Tide West Oil Company | Tulsa, OK 74136 | Oil & Gas Operator | Mar 2021 |
| 18 | Tidelands Oil Corporation | Crystal City, TX 78839 | Oil & Gas Operator | Aug 2003 |
| 19 | Tiki Oil & Gas, LLC | Cisco, TX 76437 | Oil Operator | May 2025 |
| 20 | TKL Oil Properties Inc | Konawa, OK 74849 | Oil & Gas Operator | Dec 2024 |
| 21 | Townsend Company | Abilene, TX 79608 | Oil & Gas Operator | Dec 2021 |
| 22 | Trailblazer Energy Resources, LLC | Tulsa, OK 74136 | Oil & Gas Operator | May 2025 |
| 23 | Transamerica Energy Corp. | Atlanta, GA 30356 | Oil & Gas Operator | May 2025 |
| 24 | Trek Resources, Inc. | Dallas, TX 75207 | Oil & Gas Operator | May 2025 |
| 25 | Triad Energy Corporation | Houston, TX 77057 | Oil & Gas Operator | Oct 2011 |
| 26 | Trident Corporation | Woodsboro, TX 78393 | Oil & Gas Operator | May 2025 |
| 27 | Trinity Operating (Usg), LLC | Houston, TX 77002 | Oil & Gas Operator | May 2025 |
| 28 | Tristar Oil & Gas | Freer, TX 78357 | Oil & Gas Operator | May 2025 |
| 29 | Tug Hill Operating, LLC | Fort Worth, TX 76107 | Oil & Gas Operator | Dec 2021 |
| 30 | Tundra Operating LLC | Spring, TX 77386 | Oil Operator | May 2017 |
| 31 | Turner, M. O. | San Antonio, TX 78278 | Oil & Gas Operator | Apr 2003 |
| 32 | TX Petroleum Company | Corpus Chrsti, TX 78412 | Oil & Gas Operator | Apr 1996 |