| 1 | T & T Oil Co. | San Antonio, TX 78205 | Oil & Gas Operator | Dec 2002 |
| 2 | Tag Oil | La Vernia, TX 78121 | Oil Operator | Dec 2024 |
| 3 | Tamarack Petroleum Company, Inc. | Midland, TX 79701 | Oil & Gas Operator | Dec 2024 |
| 4 | Tanglehead Operating, LLC | San Antonio, TX 78209 | Oil Operator | Dec 2024 |
| 5 | Tanglewood Oil & Gas Co. | Gouldbusk, TX 76845 | Oil & Gas Operator | Dec 2024 |
| 6 | Tanos Production, Inc. | Houston, TX 77077 | Oil & Gas Operator | Aug 2003 |
| 7 | Tejones Operating Corporation | San Antonio, TX 78217 | Oil & Gas Operator | Dec 2024 |
| 8 | Terra Locus Services | Seguin, TX 78155 | Oil & Gas Operator | Jun 2000 |
| 9 | Texas Coastal Resources LLC | Fairhope, AL 36532 | Oil Operator | Dec 2024 |
| 10 | Texas South Operating Co, Inc. | Houston, TX 77027 | Oil Operator | Dec 2024 |
| 11 | Texas Vanguard Oil Company | Austin, TX 78720 | Oil & Gas Operator | Jan 2014 |
| 12 | Texas, Les & Co. | Austin, TX 78746 | Oil & Gas Operator | Dec 2024 |
| 13 | Texcal Oil Co | Cuero, TX 77954 | Oil & Gas Operator | Feb 2006 |
| 14 | Texlark Exploration Company, Inc | Plano, TX 75074 | Oil & Gas Operator | Sep 2001 |
| 15 | Texokan Operating, Inc. | Dallas, TX 75206 | Oil & Gas Operator | Dec 2024 |
| 16 | Texstar Drilling, Inc. | Houston, TX 77084 | Oil & Gas Operator | Dec 2024 |
| 17 | Texstar Oil & Gas, LLC | Luling, TX 78648 | Oil & Gas Operator | Dec 2024 |
| 18 | Thomas Oil & Gas Company | Luling, TX 78648 | Oil & Gas Operator | Aug 2003 |
| 19 | Thomas, T. N. Oil Company | Aiken, SC 29801 | Oil & Gas Operator | Dec 2024 |
| 20 | Thorp Petroleum Corporation | Houston, TX 77002 | Oil & Gas Operator | Feb 2014 |
| 21 | Three J Energy, Inc. | Seguin, TX 78155 | Oil & Gas Operator | Dec 2024 |
| 22 | Tidal Petroleum, Inc. | Schertz, TX 78154 | Oil & Gas Operator | Dec 2024 |
| 23 | Tipperary Oil & Gas Corp | Denver, CO 80202 | Oil & Gas Operator | May 2014 |
| 24 | Titan Exploration LLC | Denver, CO 80202 | Oil & Gas Operator | Nov 2024 |
| 25 | Tiza Energy, Inc. | Austin, TX 78715 | Oil & Gas Operator | Dec 2024 |
| 26 | Tiza Operating Company | Austin, TX 78716 | Oil & Gas Operator | Jan 2000 |
| 27 | TK Drilling Corp. | Tulsa, OK 74133 | Oil & Gas Operator | Sep 2024 |
| 28 | Tri-County Operating Company | Seguin, TX 78156 | Gas Operator | Feb 1997 |
| 29 | Trident Corporation | Woodsboro, TX 78393 | Oil & Gas Operator | Dec 2024 |
| 30 | Trinity Operating (Usg), LLC | Houston, TX 77002 | Oil & Gas Operator | Dec 2024 |
| 31 | Triple H Production | Stockdale, TX 78160 | Oil Operator | Dec 2024 |
| 32 | Trivista Operating LLC | Giddings, TX 78942 | Oil & Gas Operator | Dec 2024 |
| 33 | Truth Resources LP | Houston, TX 77090 | Oil Operator | Sep 2021 |
| 34 | Tucker Operating Co., Inc. | Victoria, TX 77903 | Oil & Gas Operator | Dec 2024 |
| 35 | Tularosa Operating Company | Kerrville, TX 78029 | Oil & Gas Operator | Mar 2024 |