| 1 | Eck Petroleum LLC | Kingman, KS 67068 | Oil Operator | Nov 2019 |
| 2 | Eclipse Petroleum Corporation | La Grange, TX 78945 | Oil & Gas Operator | Aug 2003 |
| 3 | Eclipse Services, Inc. * | La Grange, TX 78945 | Oil & Gas Operator | Jul 2003 |
| 4 | Edco Energy, Inc. | Austin, TX 78738 | Oil & Gas Operator | May 2003 |
| 5 | Edge Petroleum Oper. Co., Inc. | Houston, TX 77042 | Oil & Gas Operator | Nov 2010 |
| 6 | El Paso E&P Company, L.P. | Houston, TX 77002 | Oil & Gas Operator | Mar 2013 |
| 7 | El Paso Production Oil & Gas Co. | Houston, TX 77252 | Oil & Gas Operator | Jun 2025 |
| 8 | Eland Energy Inc | Dallas, TX 75248 | Oil & Gas Operator | Apr 2025 |
| 9 | Elliott Oil & Gas Company | The Woodlands, TX 77380 | Oil & Gas Operator | Sep 2006 |
| 10 | Elliott Oil & Gas Operating Co. | Magnolia, TX 77354 | Oil & Gas Operator | Jun 2025 |
| 11 | Elliott Oil Company, L.P. | Magnolia, TX 77354 | Oil & Gas Operator | Jun 2025 |
| 12 | Ellsworth, H. P. O&G Properties | Corpus Chrsti, TX 78413 | Oil & Gas Operator | Jun 2025 |
| 13 | Emerald Oil & Gas LC | Fort Worth, TX 76109 | Oil & Gas Operator | Jun 2025 |
| 14 | Encana Oil & Gas (USA) Inc. | Denver, CO 80202 | Oil & Gas Operator | Oct 2020 |
| 15 | Encino Exploration, Inc. | George West, TX 78022 | Oil & Gas Operator | Jun 2025 |
| 16 | Enduring Resources, LLC | Greenwood VLG, CO 80111 | Oil & Gas Operator | Apr 2025 |
| 17 | Energy Equity Company | Columbus, MT 59019 | Oil & Gas Operator | Apr 2025 |
| 18 | Enerquest Oil & Gas LLC | Oklahoma City, OK 73114 | Oil & Gas Operator | Mar 2025 |
| 19 | Enron Oil & Gas Company | Houston, TX 77210 | Oil & Gas Operator | Dec 1999 |
| 20 | Enserch Exploration Inc | Dallas, TX 75206 | Oil & Gas Operator | Apr 2015 |
| 21 | Ensign Operating LLC | Houston, TX 77086 | Oil & Gas Operator | Feb 2023 |
| 22 | EOG Resources, Inc. | Midland, TX 79702 | Oil & Gas Operator | Jun 2025 |
| 23 | EP Energy E&P Company, LP | Houston, TX 77210 | Oil & Gas Operator | Jan 2023 |
| 24 | EP Operating Limited Partnership | Dallas, TX 75201 | Oil & Gas Operator | Feb 1995 |
| 25 | Epic Permian Operating, LLC | Midland, TX 79705 | Oil & Gas Operator | Jan 2025 |
| 26 | Esenjay Exploration, Inc | Houston, TX 77042 | Oil & Gas Operator | Mar 2025 |
| 27 | Esenjay Petroleum Corp. | Corpus Chrsti, TX 78471 | Oil & Gas Operator | Jul 1998 |
| 28 | Espada Operating LLC | San Antonio, TX 78209 | Oil Operator | Jun 2025 |
| 29 | Esperanza Energy Corp. | Prosper, TX 75078 | Oil & Gas Operator | Mar 2015 |
| 30 | Estate Of James L. Nelson | Pettus, TX 78146 | Oil & Gas Operator | Jun 2025 |
| 31 | Etc Field Services LLC | San Antonio, TX 78258 | Oil Operator | Jun 2018 |
| 32 | Etoco Incorporated | Houston, TX 77002 | Oil & Gas Operator | May 2005 |
| 33 | Evans, Julian | Houston, TX 77024 | Oil & Gas Operator | Nov 1995 |
| 34 | Everest Minerals Corp. | Corpus Chrsti, TX 78403 | Oil & Gas Operator | Apr 2001 |
| 35 | Everest Resource Company | Corpus Chrsti, TX 78403 | Oil & Gas Operator | Jun 2025 |
| 36 | Exco Resources Inc | Dallas, TX 75251 | Oil & Gas Operator | Mar 2025 |
| 37 | Export Petroleum Corporation | Fort Worth, TX 76147 | Oil & Gas Operator | Jun 2025 |
| 38 | Express Oil Co. | Hallettsville, TX 77964 | Oil & Gas Operator | Jun 2025 |
| 39 | Extex Operating Company | Houston, TX 77057 | Oil & Gas Operator | Jun 2025 |
| 40 | Exxon Corporation | Houston, TX 77210 | Oil & Gas Operator | Jun 2024 |