| 1 | Tanglewood Oil & Gas Co. | Gouldbusk, TX 76845 | Oil & Gas Operator | Mar 2025 |
| 2 | Tech Resources, Inc. | Georgetown, TX 78628 | Oil & Gas Operator | Dec 2001 |
| 3 | Terrafina Energy, LLC | San Antonio, TX 78280 | Oil & Gas Operator | Mar 2025 |
| 4 | Texaco E & P Inc | Houston, TX 77099 | Oil & Gas Operator | Mar 2025 |
| 5 | Texas American Resources Company | Austin, TX 78701 | Oil & Gas Operator | Mar 2025 |
| 6 | Texokan Operating, Inc. | Dallas, TX 75206 | Oil & Gas Operator | Mar 2025 |
| 7 | Texron Operating, LLC | Bulverde, TX 78163 | Oil & Gas Operator | Mar 2025 |
| 8 | Thalmann Oil Field Service, Inc. | Carrizo SPGS, TX 78834 | Oil & Gas Operator | Mar 2008 |
| 9 | Thalmann Oilfield | Carrizo SPGS, TX 78834 | Oil Operator | Mar 2025 |
| 10 | Thalmann, David Vac Service Inc | Carrizo SPGS, TX 78834 | Oil & Gas Operator | Mar 2025 |
| 11 | Three Arrow Operating Company | Midland, TX 79705 | Oil & Gas Operator | Feb 2018 |
| 12 | Tidal Petroleum, Inc. | Schertz, TX 78154 | Oil & Gas Operator | Mar 2025 |
| 13 | Tidelands Oil Corporation | Crystal City, TX 78839 | Oil & Gas Operator | Aug 2003 |
| 14 | Tidemark Petroleum, Inc. | San Antonio, TX 78209 | Oil & Gas Operator | Jul 2002 |
| 15 | Tipperary Oil & Gas Corp | Denver, CO 80202 | Oil & Gas Operator | May 2014 |
| 16 | Tiza Energy, Inc. | Austin, TX 78715 | Oil & Gas Operator | Mar 2025 |
| 17 | Touchstone Resources USA, Inc. | Houston, TX 77002 | Oil & Gas Operator | Oct 2006 |
| 18 | Trans-Texas Resources, Inc. | Tyler, TX 75702 | Oil & Gas Operator | Feb 1993 |
| 19 | Travers Resources, Inc. | Houston, TX 77056 | Oil & Gas Operator | Mar 2025 |
| 20 | Trek Resources, Inc. | Dallas, TX 75207 | Oil & Gas Operator | Mar 2025 |
| 21 | Trinity Operating (Usg), LLC | Houston, TX 77002 | Oil & Gas Operator | Mar 2025 |
| 22 | Trium, LTD. | Laredo, TX 78041 | Oil Operator | Mar 2025 |
| 23 | Txco Resources Inc. | San Antonio, TX 78280 | Oil & Gas Operator | Mar 2025 |