| 1 | Eagle Ford Hunter Resources,Inc. | Houston, TX 77024 | Oil & Gas Operator | Apr 2013 |
| 2 | Earthstone Operating, LLC | The Woodlands, TX 77380 | Oil & Gas Operator | Jul 2025 |
| 3 | Eei Operating Inc. | Plano, TX 75093 | Oil & Gas Operator | May 2015 |
| 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 | Eex Operating, L.P. | Houston, TX 77060 | Oil & Gas Operator | Jul 2003 |
| 7 | El Paso E&P Company, L.P. | Houston, TX 77002 | Oil & Gas Operator | Mar 2013 |
| 8 | El Paso Production Oil & Gas Co. | Houston, TX 77252 | Oil & Gas Operator | Oct 2025 |
| 9 | Ellstrom Energy Company | Kingwood, TX 77339 | Oil & Gas Operator | Nov 2000 |
| 10 | Ellsworth, H. P. O&G Properties | Corpus Chrsti, TX 78413 | Oil & Gas Operator | Oct 2025 |
| 11 | Encana Oil & Gas (USA) Inc. | Denver, CO 80202 | Oil & Gas Operator | Oct 2020 |
| 12 | Energy Development Corporation | Houston, TX 77067 | Oil & Gas Operator | Dec 2024 |
| 13 | Energy Transfer Crude Marketing LLC | Dallas, TX 75225 | Oil Operator | May 2025 |
| 14 | Enerquest Oil & Gas LLC | Oklahoma City, OK 73114 | Oil & Gas Operator | Jun 2025 |
| 15 | Enserch Exploration Inc | Dallas, TX 75206 | Oil & Gas Operator | Apr 2015 |
| 16 | EOG Resources, Inc. | Midland, TX 79702 | Oil & Gas Operator | Oct 2025 |
| 17 | EP Energy E&P Company, LP | Houston, TX 77210 | Oil & Gas Operator | Jan 2023 |
| 18 | EP Operating Limited Partnership | Dallas, TX 75201 | Oil & Gas Operator | Feb 1995 |
| 19 | Escondido Petroleum Company, Inc | Houston, TX 77063 | Oil & Gas Operator | Oct 2025 |
| 20 | Esenjay Petroleum Corp. | Corpus Chrsti, TX 78471 | Oil & Gas Operator | Jul 1998 |
| 21 | Etc Texas Pipeline, LTD. | Dallas, TX 75225 | Oil Operator | Sep 2023 |
| 22 | European-Southwest Co. | Houston, TX 77254 | Oil & Gas Operator | Oct 2025 |
| 23 | Evans, Julian | Houston, TX 77024 | Oil & Gas Operator | Nov 1995 |
| 24 | Everest Minerals Corp. | Corpus Chrsti, TX 78403 | Oil & Gas Operator | Apr 2001 |
| 25 | Everest Resource Company | Corpus Chrsti, TX 78403 | Oil & Gas Operator | Oct 2025 |
| 26 | Express Oil Co. | Hallettsville, TX 77964 | Oil & Gas Operator | Oct 2025 |
| 27 | Exxon Corporation | Houston, TX 77210 | Oil & Gas Operator | Jun 2024 |