| 1 | E. A. Courtney | | Oil & Gas Operator | Oct 1978 |
| 2 | Edwin L Cox & Berry R Cox-Eni | | Oil & Gas Operator | May 1986 |
| 3 | Edwin L. Cox | | Oil & Gas Operator | May 1986 |
| 4 | Eex Corporation | Houston, TX 77060 | Oil & Gas Operator | Feb 2000 |
| 5 | Eex E&P Company, L.P. | Houston, TX 77060 | Oil & Gas Operator | Jul 2003 |
| 6 | Eland Energy Inc | Dallas, TX 75248 | Oil & Gas Operator | Jul 2025 |
| 7 | Elf Aquitaine Operating, Inc. | | Oil & Gas Operator | Jan 1992 |
| 8 | Energy Corp. Of America, Inc. | | Oil & Gas Operator | Aug 1998 |
| 9 | Energy Development Corporation | Houston, TX 77067 | Oil & Gas Operator | Dec 2024 |
| 10 | Energy Management Corp. | | Oil & Gas Operator | Apr 1999 |
| 11 | Energy Partners, LTD. | New Orleans, LA 70170 | Oil & Gas Operator | Aug 2012 |
| 12 | Energy Properties Inc. | | Oil & Gas Operator | Dec 2023 |
| 13 | Energy Reserves Group | Houston, TX 770563020 | Oil & Gas Operator | Apr 1996 |
| 14 | Energy Resource Associates Inc | | Gas Operator | Nov 1988 |
| 15 | Energy Sources, Inc. | | Oil & Gas Operator | Nov 1990 |
| 16 | Energy Xxi Gulf Coast, Inc. | | Oil & Gas Operator | Dec 2008 |
| 17 | Energy Xxi Onshore, LLC | | Oil & Gas Operator | Dec 2023 |
| 18 | Enervest Operating LLC | Houston, TX 77002 | Oil & Gas Operator | Oct 2025 |
| 19 | Enlink Lig, LLC | | Oil Operator | Jan 2025 |
| 20 | Enserch Exploration Inc | Dallas, TX 75206 | Oil & Gas Operator | Apr 2015 |
| 21 | Enstar Petroleum Company | | Oil & Gas Operator | Aug 1985 |
| 22 | Entex, Inc. | | Oil & Gas Operator | Dec 1984 |
| 23 | Equitable Petroleum Corp. | | Oil & Gas Operator | Jan 1999 |
| 24 | Est Of WM G Helis (A Partnership) | | Oil & Gas Operator | Dec 2009 |
| 25 | Evangeline Natural Resources, LLC | | Oil & Gas Operator | Jan 2025 |
| 26 | Exchange Oil & Gas Corporation | Tulsa, OK 74103 | Oil & Gas Operator | Oct 1987 |
| 27 | Exco Resources Inc | Dallas, TX 75251 | Oil & Gas Operator | Jun 2025 |
| 28 | Exoro Energy, L.L.C. | | Oil & Gas Operator | Jun 2021 |
| 29 | Expert Oil & Gas, L.L.C. | | Oil & Gas Operator | Nov 2024 |
| 30 | Extex Operating Company | Houston, TX 77057 | Oil & Gas Operator | Oct 2025 |
| 31 | Exxon Corporation | Houston, TX 77210 | Oil & Gas Operator | Jun 2024 |