| 1 | Talisman Energy USA Inc. | The Woodlands, TX 77381 | Oil & Gas Operator | May 2016 |
| 2 | Tana Oil And Gas Corporation | Irving, TX 75062 | Oil & Gas Operator | Mar 2000 |
| 3 | Tanos Production, Inc. | Houston, TX 77077 | Oil & Gas Operator | Aug 2003 |
| 4 | Tare Resources, LLC | Corpus Chrsti, TX 78426 | Oil & Gas Operator | Oct 2025 |
| 5 | Targa Midstream Services LLC | Houston, TX 77002 | Oil Operator | Mar 2023 |
| 6 | Teal Operating, LLC | Dallas, TX 75225 | Oil & Gas Operator | Oct 2021 |
| 7 | Terrafina Energy, LLC | San Antonio, TX 78280 | Oil & Gas Operator | Oct 2025 |
| 8 | Teton Petroleum Corporation | Kerrville, TX 78028 | Oil & Gas Operator | Oct 2025 |
| 9 | Texaco E & P Inc | Houston, TX 77099 | Oil & Gas Operator | Oct 2025 |
| 10 | Texas Independent Explor LTD. | Houston, TX 77024 | Oil & Gas Operator | Oct 2025 |
| 11 | Texas Independent Explor., Inc. | Houston, TX 77002 | Oil & Gas Operator | Oct 2002 |
| 12 | Texas Lone Star Petroleum Corp. | Corpus Chrsti, TX 78401 | Oil & Gas Operator | Dec 2013 |
| 13 | Texas Secondary Oil Corporation | Devine, TX 78016 | Oil & Gas Operator | Oct 2025 |
| 14 | Texas Southern Petroleum Corp. | Corpus Chrsti, TX 78410 | Oil & Gas Operator | Oct 2025 |
| 15 | Texas, Les & Co. | Austin, TX 78746 | Oil & Gas Operator | Oct 2025 |
| 16 | Texas, Les C., LTD. | Houston, TX 77095 | Oil & Gas Operator | Dec 2006 |
| 17 | Texcal Energy (GP) LLC | Denver, CO 80202 | Oil & Gas Operator | Mar 2016 |
| 18 | Texegy Operating Company LLC | Corpus Chrsti, TX 78401 | Oil & Gas Operator | Dec 2024 |
| 19 | Texona Petroleum Corporation | Houston, TX 77084 | Oil & Gas Operator | Aug 2003 |
| 20 | Texoz E&P I, Inc. | Houston, TX 77077 | Oil & Gas Operator | Oct 2025 |
| 21 | Texron Operating, LLC | Bulverde, TX 78163 | Oil & Gas Operator | Oct 2025 |
| 22 | Thalmann Oilfield | Carrizo SPGS, TX 78834 | Oil Operator | Oct 2025 |
| 23 | Thomas Exploration & Devel., Inc | Jourdanton, TX 78026 | Oil & Gas Operator | Oct 2025 |
| 24 | Three J Energy, Inc. | Seguin, TX 78155 | Oil & Gas Operator | Oct 2025 |
| 25 | Tidal Petroleum, Inc. | Schertz, TX 78154 | Oil & Gas Operator | Oct 2025 |
| 26 | Torch Operating Company | Houston, TX 77010 | Oil & Gas Operator | Mar 2015 |
| 27 | Toreador Exploration & Prod Inc | Dallas, TX 75240 | Oil & Gas Operator | Feb 2008 |
| 28 | Tracker Oil & Gas, Inc. | Bastrop, TX 78602 | Oil & Gas Operator | Oct 2025 |
| 29 | Trek Resources, Inc. | Dallas, TX 75207 | Oil & Gas Operator | Oct 2025 |
| 30 | Tri-C Resources, Inc. | Houston, TX 77024 | Oil & Gas Operator | Aug 2009 |
| 31 | Tri-Union Development Corp. | Houston, TX 77002 | Oil & Gas Operator | Oct 2025 |
| 32 | Triangle Three Resources L.L.C. | Dallas, TX 75240 | Oil & Gas Operator | Oct 2024 |
| 33 | Trident Corporation | Woodsboro, TX 78393 | Oil & Gas Operator | Oct 2025 |
| 34 | Trinity Operating (Usg), LLC | Houston, TX 77002 | Oil & Gas Operator | Oct 2025 |
| 35 | Triple L Oil Company | Corpus Chrsti, TX 78469 | Oil & Gas Operator | Jan 1998 |
| 36 | Trium, LTD. | Laredo, TX 78041 | Oil Operator | Oct 2025 |
| 37 | Tucker Petroleum, Inc. | Corpus Chrsti, TX 78468 | Oil & Gas Operator | Oct 2025 |
| 38 | TX Petroleum Company | Corpus Chrsti, TX 78412 | Oil & Gas Operator | Apr 1996 |