| 1 | T - C Oil Company | Refugio, TX 78377 | Oil & Gas Operator | Jan 2012 |
| 2 | T-C Oil Company, LLC | Refugio, TX 78377 | Oil & Gas Operator | Apr 2026 |
| 3 | T.D. Operating Company, Inc. | New Braunfels, TX 78130 | Oil & Gas Operator | Nov 1999 |
| 4 | Talon Development Company | Boerne, TX 78006 | Oil & Gas Operator | Sep 2007 |
| 5 | Tamarack Petroleum Company, Inc. | Midland, TX 79701 | Oil & Gas Operator | Apr 2026 |
| 6 | Tana Oil And Gas Corporation | Irving, TX 75062 | Oil & Gas Operator | Mar 2000 |
| 7 | Taos Resources Operating Co LLC | Houston, TX 77037 | Oil & Gas Operator | Dec 2019 |
| 8 | Tare Resources, LLC | Corpus Chrsti, TX 78426 | Oil & Gas Operator | Apr 2026 |
| 9 | Tasca Exploration Company | Houston, TX 77257 | Oil & Gas Operator | Jun 2002 |
| 10 | Teco Oil & Gas, Inc. | Tampa, FL 33601 | Oil & Gas Operator | Nov 1997 |
| 11 | Teco Operating Company | Athens, TX 75751 | Oil & Gas Operator | Jun 2001 |
| 12 | Tecpetrol Operating LLC | Houston, TX 77027 | Oil & Gas Operator | Dec 2015 |
| 13 | Tema Oil And Gas Company | Houston, TX 77084 | Oil & Gas Operator | Apr 2026 |
| 14 | Tema Oil And Gas, LLC | Houston, TX 77040 | Oil & Gas Operator | Apr 2000 |
| 15 | Tempest Energy Resources, LP | Houston, TX 77251 | Oil & Gas Operator | Jun 2013 |
| 16 | Tepco, Inc. | Houston, TX 77002 | Oil & Gas Operator | Oct 1999 |
| 17 | Tepee Petroleum Company, Inc. | Houston, TX 77098 | Oil & Gas Operator | Feb 2014 |
| 18 | Terrafina Energy, LLC | San Antonio, TX 78280 | Oil & Gas Operator | Apr 2026 |
| 19 | Tesoro E&P Company, L.P. | San Antonio, TX 78216 | Oil & Gas Operator | Jan 2000 |
| 20 | Tesoro Expl. & Prod. Company | San Antonio, TX 78216 | Gas Operator | Sep 2010 |
| 21 | Texacal, Inc. | Newport Beach, CA 92660 | Oil & Gas Operator | Apr 2026 |
| 22 | Texaco E & P Inc. | Houston, TX 77099 | Oil & Gas Operator | Apr 2026 |
| 23 | Texakoma E & P, LLC | Plano, TX 75024 | Oil & Gas Operator | Apr 2026 |
| 24 | Texakoma Oil & Gas Corp | Dallas, TX 75240 | Oil & Gas Operator | Sep 2014 |
| 25 | Texakoma Operating, L.P. | Plano, TX 75024 | Oil & Gas Operator | Mar 2025 |
| 26 | Texana Operating Company | Houston, TX 77090 | Oil & Gas Operator | Apr 2026 |
| 27 | Texcal Energy (GP) LLC | Denver, CO 80202 | Oil & Gas Operator | Mar 2016 |
| 28 | Tharp Operating Company | Houston, TX 77070 | Oil & Gas Operator | Nov 2014 |
| 29 | Thunderbird Energy, Inc. | Norman, OK 73069 | Oil & Gas Operator | Apr 2026 |
| 30 | Tidal Petroleum, Inc. | Schertz, TX 78154 | Oil & Gas Operator | Apr 2026 |
| 31 | Tidewater Minerals Corporation | Orange Grove, TX 78372 | Oil & Gas Operator | Apr 2026 |
| 32 | Tiki Oil & Gas, LLC | Cisco, TX 76437 | Oil & Gas Operator | Apr 2026 |
| 33 | Top Op, L.L.C. | Houston, TX 77077 | Oil & Gas Operator | May 2020 |
| 34 | Total E&P USA, Inc. | Houston, TX 77210 | Oil & Gas Operator | May 2025 |
| 35 | Totalfinaelf E&P USA Inc | Houston, TX 77024 | Oil & Gas Operator | Jul 2007 |
| 36 | Tpet, Inc. | Dallas, TX 75204 | Oil & Gas Operator | Mar 2008 |
| 37 | Transamerican Natural Gas Corp. | Houston, TX 77032 | Oil & Gas Operator | Aug 2000 |
| 38 | Transcontinental Minerals Corp. | The Woodlands, TX 77380 | Oil & Gas Operator | Dec 2008 |
| 39 | Transpacific Energy, LLC | Katy, TX 77450 | Oil & Gas Operator | Apr 2026 |
| 40 | Transtexas Gas Corporation | Houston, TX 77265 | Oil & Gas Operator | Aug 2005 |
| 41 | Trek Oil & Gas, Inc | Houston, TX 77002 | Oil Operator | Mar 1998 |
| 42 | Tres Operating Co., LLC | Katy, TX 77494 | Oil Operator | Apr 2026 |
| 43 | Tri-C Resources, Inc. | Houston, TX 77024 | Oil & Gas Operator | Aug 2009 |
| 44 | Tri-C Resources, LLC | Houston, TX 77024 | Oil & Gas Operator | Apr 2026 |
| 45 | Tri-Union Development Corp. | Houston, TX 77002 | Oil & Gas Operator | Apr 2026 |
| 46 | Triad Energy Corporation | Houston, TX 77057 | Oil & Gas Operator | Oct 2011 |
| 47 | Trident Corporation | Woodsboro, TX 78393 | Oil & Gas Operator | Apr 2026 |
| 48 | Trinity River Energy Oper, LLC | Houston, TX 77008 | Oil & Gas Operator | May 2018 |
| 49 | Trio Consulting & Management,LLC | Wichita Falls, TX 76307 | Oil & Gas Operator | Apr 2026 |
| 50 | Tristar Exploration, Inc | Pflugerville, TX 78660 | Oil & Gas Operator | Apr 2026 |
| 51 | Tsoco | Tuleta, TX 78162 | Oil & Gas Operator | Apr 2017 |
| 52 | Tucker Operating Co., Inc. | Victoria, TX 77903 | Oil & Gas Operator | Apr 2026 |
| 53 | Turner, M. O. | San Antonio, TX 78278 | Oil & Gas Operator | Apr 2003 |
| 54 | TX Lone Star Operating Co, LLC | Sulphur SPGS, TX 75483 | Oil & Gas Operator | Apr 2026 |