| 1 | Eagle River Energy Corporation | Broken Arrow, OK 74011 | Oil & Gas Operator | Jun 2025 |
| 2 | Earthstone Operating, LLC | The Woodlands, TX 77380 | Oil & Gas Operator | Jul 2025 |
| 3 | Edge Petroleum Oper. Co., Inc. | Houston, TX 77042 | Oil & Gas Operator | Nov 2010 |
| 4 | Edinger Engineering, Inc. | Oklahoma City, OK 73102 | Oil & Gas Operator | Jul 2025 |
| 5 | Edinger Inc. | Oklahoma City, OK 73102 | Oil & Gas Operator | Jun 2007 |
| 6 | Eex Corporation | Houston, TX 77060 | Oil & Gas Operator | Feb 2000 |
| 7 | Eex Operating, L.P. | Houston, TX 77060 | Oil & Gas Operator | Jul 2003 |
| 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 | Enduring Resources, LLC | Greenwood VLG, CO 80111 | Oil & Gas Operator | Jul 2025 |
| 13 | Enercorp Resources, Inc. | Houston, TX 77027 | Oil & Gas Operator | Dec 1993 |
| 14 | Energy Equity Company | Columbus, MT 59019 | Oil & Gas Operator | Aug 2025 |
| 15 | Energy Hunter Resources, Inc. | Houston, TX 77024 | Oil & Gas Operator | Feb 2019 |
| 16 | Energy Resource Management, Inc. | Caldwell, TX 77836 | Oil & Gas Operator | Mar 2008 |
| 17 | Enerquest Oil & Gas LLC | Oklahoma City, OK 73114 | Oil & Gas Operator | Jun 2025 |
| 18 | Enerquest Operating, LLC | Oklahoma City, OK 73114 | Oil & Gas Operator | Oct 2025 |
| 19 | Enervest Operating LLC | Houston, TX 77002 | Oil & Gas Operator | Oct 2025 |
| 20 | Enex Resources Corporation | Houston, TX 77002 | Oil & Gas Operator | Dec 2009 |
| 21 | Engelke, R. H. | San Antonio, TX 78230 | Oil & Gas Operator | Oct 2025 |
| 22 | Enpower Resources Inc. | Sugar Land, TX 77479 | Oil & Gas Operator | Oct 2025 |
| 23 | Enserch Exploration Inc | Dallas, TX 75206 | Oil & Gas Operator | Apr 2015 |
| 24 | Ensign Operating LLC | Houston, TX 77086 | Oil & Gas Operator | Feb 2023 |
| 25 | EOG Resources, Inc. | Midland, TX 79702 | Oil & Gas Operator | Oct 2025 |
| 26 | EP Operating Limited Partnership | Dallas, TX 75201 | Oil & Gas Operator | Feb 1995 |
| 27 | Esenjay Exploration, Inc | Houston, TX 77042 | Oil & Gas Operator | Jun 2025 |
| 28 | Esenjay Petroleum Corp. | Corpus Chrsti, TX 78471 | Oil & Gas Operator | Jul 1998 |
| 29 | Estate Of James L. Nelson | Pettus, TX 78146 | Oil & Gas Operator | Oct 2025 |
| 30 | Etc Field Services LLC | San Antonio, TX 78258 | Oil Operator | Jun 2018 |
| 31 | Etc Texas Pipeline, LTD. | Dallas, TX 75225 | Oil Operator | Sep 2023 |
| 32 | Exotic Oil & Gas LLC | Indiana, PA 15701-3634 | Oil & Gas Operator | Dec 2024 |
| 33 | Express Oil Co. | Hallettsville, TX 77964 | Oil & Gas Operator | Oct 2025 |
| 34 | Extex Operating Company | Houston, TX 77057 | Oil & Gas Operator | Oct 2025 |
| 35 | Exxon Corporation | Houston, TX 77210 | Oil & Gas Operator | Jun 2024 |
| 36 | Exxonmobil Oil Corp | Houston, TX 77210 | Oil & Gas Operator | Jul 2025 |