| 1 | Targa Midstream Services LLC | Houston, TX 77002 | Oil Operator | Mar 2023 |
| 2 | TDC Engineering, Inc. | Abilene, TX 79604 | Oil & Gas Operator | Apr 2025 |
| 3 | Tejas Western Corp. | Granbury, TX 76048 | Oil & Gas Operator | Jul 2018 |
| 4 | Teleo Operating, LLC | Dallas, TX 75219 | Oil & Gas Operator | Apr 2009 |
| 5 | Tep Barnett USA, LLC | Fort Worth, TX 76102 | Oil & Gas Operator | Apr 2025 |
| 6 | Texas Independent Oil Co., LLC | Argyle, TX 76226 | Oil & Gas Operator | Apr 2025 |
| 7 | Texcel Exploration, Inc. | Colorado SPGS, CO 80960 | Oil & Gas Operator | Apr 2025 |
| 8 | Texxol Operating Company, Inc. | Fort Worth, TX 76108 | Oil & Gas Operator | Apr 2025 |
| 9 | The Dehart Company LLC | Ardmore, OK 73402-0907 | Oil Operator | Jan 2025 |
| 10 | Thompson, J. Cleo | Dallas, TX 75201 | Oil & Gas Operator | May 2024 |
| 11 | Tidewater Resources Corporation | Memphis, TN 38138 | Gas Operator | Feb 2025 |
| 12 | Titan Operating, LLC | Fort Worth, TX 76102 | Oil & Gas Operator | Jun 2012 |
| 13 | Tracker Mineral | Clyde, TX 79510 | Oil & Gas Operator | Apr 2025 |
| 14 | Trinity River Energy Oper, LLC | Houston, TX 77008 | Oil & Gas Operator | May 2018 |
| 15 | Trio Consulting & Management,LLC | Wichita Falls, TX 76307 | Oil & Gas Operator | Apr 2025 |
| 16 | Trio Operating Company, Inc. | Wichita Falls, TX 76307 | Oil & Gas Operator | Apr 2006 |
| 17 | Triple G Well Service, Inc. | Muenster, TX 76252 | Oil & Gas Operator | Apr 2025 |
| 18 | Txu Gas Company | Dallas, TX 75201 | Oil & Gas Operator | Sep 2004 |
| 19 | Txu Lone Star Pipeline | Dallas, TX 75201 | Oil & Gas Operator | Oct 2003 |