| 1 | Tamarack Petroleum Company, Inc. | Midland, TX 79701 | Oil & Gas Operator | May 2026 |
| 2 | Tanglewood Oil & Gas Co. | Gouldbusk, TX 76845 | Oil & Gas Operator | May 2026 |
| 3 | Taos Resources Operating Co LLC | Houston, TX 77037 | Oil & Gas Operator | Dec 2019 |
| 4 | TDT Production, Inc. | Capitola, CA 95010 | Oil & Gas Operator | Aug 2003 |
| 5 | Tekna Synergy Corporation | Midland, TX 79702 | Oil & Gas Operator | May 2026 |
| 6 | Tex-Lee Operating Company | Giddings, TX 78942 | Oil & Gas Operator | May 2026 |
| 7 | Texakoma Oil & Gas Corp | Dallas, TX 75240 | Oil & Gas Operator | Sep 2014 |
| 8 | Texas Independent Explor LTD. | Houston, TX 77024 | Oil & Gas Operator | May 2026 |
| 9 | Texas Independent Explor., Inc. | Houston, TX 77002 | Oil & Gas Operator | Oct 2002 |
| 10 | Texas Oil And Gas Operating, LLC | Friendswood, TX 77546 | Oil & Gas Operator | May 2026 |
| 11 | Texas Onshore Energy, Inc. | Austin, TX 78704 | Oil & Gas Operator | May 2026 |
| 12 | Texas Vanguard Oil Company | Austin, TX 78720 | Oil & Gas Operator | Jan 2014 |
| 13 | Three Forks Operating Co, LLC | Flatonia, TX 78941 | Oil & Gas Operator | May 2026 |
| 14 | Tipperary Oil & Gas Corporation | Denver, CO 80202 | Oil & Gas Operator | May 2014 |
| 15 | Tiza Operating Company | Austin, TX 78716 | Oil & Gas Operator | Jan 2000 |
| 16 | Torch Operating Company | Houston, TX 77010 | Oil & Gas Operator | Mar 2015 |
| 17 | Tracker Oil & Gas, Inc. | Bastrop, TX 78602 | Oil & Gas Operator | May 2026 |
| 18 | Trivista Operating LLC | Giddings, TX 78942 | Oil & Gas Operator | May 2026 |
| 19 | Txu Fuel Company | Dallas, TX 75201 | Oil & Gas Operator | May 2004 |
| 20 | Ty-Tex Exploration, Inc. | Tyler, TX 75711 | Oil Operator | Dec 2000 |