| 1 | Talley Resources, Inc. | Houma, LA 70360 | Oil & Gas Operator | Apr 1993 |
| 2 | Tandem Energy Corporation | Houston, TX 77056 | Oil & Gas Operator | Jun 2025 |
| 3 | TDC Engineering, Inc. | Abilene, TX 79604 | Oil & Gas Operator | Jun 2025 |
| 4 | Texaco E & P Inc | Houston, TX 77099 | Oil & Gas Operator | Jun 2025 |
| 5 | Texas Consolidated Pet. Corp. | Fort Worth, TX 76109 | Oil & Gas Operator | Jun 2025 |
| 6 | Texas Secondary Oil Corporation | Devine, TX 78016 | Oil & Gas Operator | Jun 2025 |
| 7 | Thompson, J. Cleo | Dallas, TX 75201 | Oil & Gas Operator | May 2024 |
| 8 | Three J'S Petroleum, Inc. | Lubbock, TX 79423 | Oil & Gas Operator | Jun 2025 |
| 9 | Three R Oil Company | Post, TX 79356 | Oil & Gas Operator | Jun 2025 |
| 10 | Three Span Oil & Gas, Inc. | Midland, TX 79710 | Oil & Gas Operator | Jun 2025 |
| 11 | Three Summits Operating LLC | Grapevine, TX 76051 | Oil & Gas Operator | Jun 2025 |
| 12 | Titan Resources I, Inc. | Midland, TX 79701 | Oil & Gas Operator | Jun 2000 |
| 13 | TLH Production LLC | Abilene, TX 79602 | Oil & Gas Operator | Jun 2025 |
| 14 | TNCH, LLC | Colorado City, TX 79512 | Oil Operator | Jun 2025 |
| 15 | Townsend, R. F. Trustee | Dallas, TX 75201 | Oil & Gas Operator | Dec 1994 |
| 16 | Tradition Resources LLC | Houston, TX 77002 | Oil & Gas Operator | Jan 2014 |
| 17 | Tradition Resources Oper, LLC | Houston, TX 77002 | Oil & Gas Operator | Jul 2017 |
| 18 | Trail Ridge Energy PRTNS II LLC | Grapevine, TX 76051 | Oil & Gas Operator | Jun 2017 |
| 19 | Trek Resources, Inc. | Dallas, TX 75207 | Oil & Gas Operator | Jun 2025 |
| 20 | Triag Energy Operating, Inc. | Midland, TX 79701 | Oil & Gas Operator | Jun 2014 |
| 21 | Trio Operating Company, Inc. | Wichita Falls, TX 76307 | Oil & Gas Operator | Apr 2006 |
| 22 | Tsar Energy, LLC | Dallas, TX 75205 | Oil & Gas Operator | Jun 2025 |
| 23 | Tucker Drilling Company, Inc. | San Angelo, TX 76903 | Oil & Gas Operator | Jul 1996 |
| 24 | Tyl Oil | Canon City, CO 81212 | Gas Operator | May 1994 |