| 1 | Tabco Exploration Inc. | New Orleans, LA 70131 | Oil & Gas Operator | Dec 1998 |
| 2 | Tana Exploration Company LLC | Dallas, TX 75219 | Oil & Gas Operator | Aug 2021 |
| 3 | TDX Energy, LLC | Shreveport, LA 71101 | Oil & Gas Operator | Dec 2024 |
| 4 | Teal Petroleum Co. | | Oil & Gas Operator | Sep 1978 |
| 5 | Tensas Delta Expl Co., LLC | Shreveport, LA 71101-5323 | Oil & Gas Operator | Jul 2021 |
| 6 | Texaco E & P Inc | Houston, TX 77099 | Oil & Gas Operator | Oct 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 Pacific Oil Company Inc. | | Oil & Gas Operator | Dec 1980 |
| 10 | Texas Petroleum Investment Company | Houston, TX 77057 | Oil & Gas Operator | Oct 2025 |
| 11 | Tiger Petroleum | | Oil Operator | Sep 2002 |
| 12 | Toce Energy, L.L.C. | | Oil & Gas Operator | Dec 2017 |
| 13 | Toce Oil Company | | Oil & Gas Operator | Dec 2014 |
| 14 | Tom Littlepage Oil Properties | | Oil & Gas Operator | Dec 1984 |
| 15 | Trace Operators, Inc. | | Oil & Gas Operator | Nov 2024 |
| 16 | Transcontinental Gas P/L Corp. | | Oil & Gas Operator | Dec 2009 |
| 17 | Transcontinental Gas Pipeline Co LLC | | Oil Operator | Jan 2025 |