| 1 | T-Square Petroleum Co. | Rising Star, TX 76471 | Oil & Gas Operator | Mar 2025 |
| 2 | T. L. J. Incorporated | Big Lake, TX 76932 | Oil & Gas Operator | Dec 1998 |
| 3 | T.L.S. Oil Co. | Hawley, TX 79525 | Oil & Gas Operator | Mar 2025 |
| 4 | Tamarack Petroleum Company, Inc. | Midland, TX 79701 | Oil & Gas Operator | Mar 2025 |
| 5 | Tandem Energy Corporation | Houston, TX 77056 | Oil & Gas Operator | Mar 2025 |
| 6 | Targo Oil & Gas, Inc. | Abilene, TX 79608 | Oil & Gas Operator | Mar 2025 |
| 7 | TCF Energy, Inc. | Midland, TX 79704 | Oil & Gas Operator | Dec 2004 |
| 8 | Teaco | Snyder, TX 79550 | Oil & Gas Operator | Jan 1998 |
| 9 | Telesis Operating Co. | Fort Worth, TX 76116 | Oil & Gas Operator | Mar 2025 |
| 10 | Terrick Resources | Midland, TX 79708 | Oil & Gas Operator | Jul 2005 |
| 11 | Tex-Am Petroleum Corp. | Eastland, TX 76448 | Oil & Gas Operator | Mar 2025 |
| 12 | Tex-Ann Oil & Gas Services, Inc. | Abilene, TX 79608 | Oil & Gas Operator | Mar 2025 |
| 13 | Texas State Oil Co. | Irving, TX 75062 | Oil & Gas Operator | Mar 2017 |
| 14 | Texas United Geoproduction, Inc. | Abilene, TX 79606 | Oil & Gas Operator | Mar 2025 |
| 15 | Texdon Operating | Breckenridge, TX 76424 | Oil & Gas Operator | Jun 2005 |
| 16 | Texokan Operating, Inc. | Dallas, TX 75206 | Oil & Gas Operator | Mar 2025 |
| 17 | Texxol Operating Company, Inc. | Fort Worth, TX 76108 | Oil & Gas Operator | Mar 2025 |
| 18 | Thrifty Well Service | Rice, TX 75155 | Oil & Gas Operator | Jun 2009 |
| 19 | THT Covenant Holdings, LLC | Wichita Falls, TX 76307 | Oil Operator | Mar 2025 |
| 20 | Tidwell Production Company | Sonora, TX 76950 | Oil & Gas Operator | Mar 2025 |
| 21 | TK Drilling Corp. | Tulsa, OK 74133 | Oil & Gas Operator | Dec 2024 |
| 22 | TK Operating | Cross Plains, TX 76443 | Oil & Gas Operator | Mar 2025 |
| 23 | Todd, J R Oil & Investments, Inc | Dallas, TX 75206 | Oil & Gas Operator | Jun 2002 |
| 24 | Toklan Oil And Gas Corporation | Tulsa, OK 74136 | Oil & Gas Operator | Jan 2025 |
| 25 | Torch Operating LLC | Fort Worth, TX 76135 | Oil & Gas Operator | Oct 2020 |
| 26 | Trace Energy Management Inc | Weatherford, TX 76086 | Oil & Gas Operator | Mar 2025 |
| 27 | Tracer Operating, Inc. | Graham, TX 76450 | Oil & Gas Operator | Mar 2025 |
| 28 | Trans Oil Marketing LLC | Abilene, TX 79608 | Oil Operator | Aug 2023 |
| 29 | Transcontinental Shale L.L.C. | Austin, TX 78717 | Oil & Gas Operator | Feb 2016 |
| 30 | Trek Resources, Inc. | Dallas, TX 75207 | Oil & Gas Operator | Mar 2025 |
| 31 | Tri Sportsmen Energy, Inc. | Austin, TX 78746 | Oil & Gas Operator | Mar 2025 |
| 32 | Triple Singleton, Inc. | Santa Fe, TX 77510 | Oil & Gas Operator | Dec 2020 |
| 33 | Trumter Petroleum Corporation | Fort Worth, TX 76185 | Oil & Gas Operator | Aug 1998 |
| 34 | Tuckco Petroleum Corporation | Andrews, TX 79714 | Oil & Gas Operator | Mar 2025 |
| 35 | Turning Point Oil, Inc. | Eastland, TX 76448 | Oil & Gas Operator | Jan 2021 |
| 36 | Txu Lone Star Pipeline | Dallas, TX 75201 | Oil & Gas Operator | Oct 2003 |