| 1 | T.O.I. | Midland, TX 79710 | Oil & Gas Operator | Mar 2001 |
| 2 | Taggart Oil Co., Inc. | | Oil Operator | Oct 1992 |
| 3 | Tellurian Operating LLC | | Oil & Gas Operator | Jun 2024 |
| 4 | Tenneco Oil Company | Oklahoma City, OK 73125 | Oil & Gas Operator | Sep 2025 |
| 5 | Tensas Delta Land Company | | Oil & Gas Operator | Apr 2002 |
| 6 | Texaco E & P Inc. | Houston, TX 77099 | Oil & Gas Operator | Dec 2025 |
| 7 | Texaco Inc | Kingfisher, OK 73750 | Oil & Gas Operator | Dec 2017 |
| 8 | Texaco Producing Inc. | Rock Springs, WY 82901 | Oil & Gas Operator | Dec 2000 |
| 9 | Texas Gas Exploration Corp. | | Oil & Gas Operator | Nov 1986 |
| 10 | Texas Gas Transmission Corp. | | Oil Operator | Aug 2003 |
| 11 | Texas Gas Transmission, LLC | Owensboro, KY 42301 | Oil & Gas Operator | Dec 2024 |
| 12 | Texas General Petroleum Corp | | Oil & Gas Operator | Aug 1984 |
| 13 | Texas Ind. Exploration, Inc. | | Oil & Gas Operator | Oct 2001 |
| 14 | Texex Petroleum Corporation | | Oil & Gas Operator | Dec 2024 |
| 15 | Tigner Walker | | Oil & Gas Operator | Dec 2021 |
| 16 | Tipco | Shreveport, LA 71104-3047 | Oil & Gas Operator | May 1988 |
| 17 | Tma Production, LLC | | Oil Operator | Dec 2024 |
| 18 | TNC Energy, LLC | Lubbock, TX 79401 | Oil & Gas Operator | Nov 2016 |
| 19 | Total Minatome Corporation | Houston, TX 77210 | Oil & Gas Operator | Dec 1998 |
| 20 | Trickle Down Oil, Inc. | | Oil & Gas Operator | Feb 2016 |
| 21 | Trinity River Energy Oper, LLC | Houston, TX 77008 | Oil & Gas Operator | May 2018 |
| 22 | Txo Production Corp. | Ganado, TX 77962 | Oil & Gas Operator | Aug 2022 |
| 23 | Txo Production Corp/Amh O&G Co | | Oil & Gas Operator | Dec 1990 |
| 24 | Tygr Operating Company, LLC | | Oil & Gas Operator | Nov 2024 |