| 1 | Edge Petroleum Oper. Co., Inc. | Houston, TX 77042 | Oil & Gas Operator | Nov 2010 |
| 2 | Eex Corporation | Houston, TX 77060 | Oil & Gas Operator | Feb 2000 |
| 3 | Eex E&P Company, L.P. | Houston, TX 77060 | Oil & Gas Operator | Jul 2003 |
| 4 | Eex Operating, L.P. | Houston, TX 77060 | Oil & Gas Operator | Jul 2003 |
| 5 | El Campo Operating, LLC | Dallas, TX 75206 | Oil & Gas Operator | Feb 2011 |
| 6 | El Dorado Resources Inc. | Waco, TX 76710 | Oil & Gas Operator | Oct 2009 |
| 7 | El Paso E&P Company, L.P. | Houston, TX 77002 | Oil & Gas Operator | Mar 2013 |
| 8 | El Paso Production Company | Houston, TX 77002 | Oil & Gas Operator | Mar 2016 |
| 9 | El Paso Production Oil & Gas Co. | Houston, TX 77252 | Oil & Gas Operator | Oct 2025 |
| 10 | Eland Energy Inc | Dallas, TX 75248 | Oil & Gas Operator | Jul 2025 |
| 11 | Eldon Oil Co. | Three Rivers, TX 78071 | Oil & Gas Operator | Oct 2025 |
| 12 | Elliott Oil & Gas Company | The Woodlands, TX 77380 | Oil & Gas Operator | Sep 2006 |
| 13 | Ellsworth, H. P. O&G Properties | Corpus Chrsti, TX 78413 | Oil & Gas Operator | Oct 2025 |
| 14 | Emerald Oil & Gas LC | Fort Worth, TX 76109 | Oil & Gas Operator | Oct 2025 |
| 15 | Encino Exploration, Inc. | George West, TX 78022 | Oil & Gas Operator | Oct 2025 |
| 16 | Energy 2000, Inc. | Reno, NV 89501 | Oil & Gas Operator | Oct 2025 |
| 17 | Energy Development Corporation | Houston, TX 77067 | Oil & Gas Operator | Dec 2024 |
| 18 | Energyquest II, LLC | The Woodlands, TX 77381 | Oil & Gas Operator | Jun 2025 |
| 19 | Enerquest Operating, LLC | Oklahoma City, OK 73114 | Oil & Gas Operator | Oct 2025 |
| 20 | Engroup Resources, L.P. | Houston, TX 77002 | Oil & Gas Operator | Oct 2025 |
| 21 | Enron Oil & Gas Company | Houston, TX 77210 | Oil & Gas Operator | Dec 1999 |
| 22 | Enserch Exploration Inc | Dallas, TX 75206 | Oil & Gas Operator | Apr 2015 |
| 23 | EOG Resources, Inc. | Midland, TX 79702 | Oil & Gas Operator | Oct 2025 |
| 24 | EP Energy E&P Company, LP | Houston, TX 77210 | Oil & Gas Operator | Jan 2023 |
| 25 | Erin Oil Co. | Midland, TX 79707 | Oil & Gas Operator | Oct 2025 |
| 26 | Esenjay Petroleum Corp. | Corpus Chrsti, TX 78471 | Oil & Gas Operator | Jul 1998 |
| 27 | Etc Field Services LLC | San Antonio, TX 78258 | Oil Operator | Jun 2018 |
| 28 | Etoco, L.P. | Houston, TX 77002 | Oil & Gas Operator | Oct 2025 |
| 29 | European-Southwest Co. | Houston, TX 77254 | Oil & Gas Operator | Oct 2025 |
| 30 | Everest Minerals Corp. | Corpus Chrsti, TX 78403 | Oil & Gas Operator | Apr 2001 |
| 31 | Excalibur E & P, LLC | Johnson City, TX 78636 | Oil & Gas Operator | Oct 2025 |
| 32 | Exok, Inc. | Oklahoma City, OK 73116 | Oil & Gas Operator | Jun 2025 |
| 33 | Express Oil Co. | Hallettsville, TX 77964 | Oil & Gas Operator | Oct 2025 |
| 34 | Exxon Corporation | Houston, TX 77210 | Oil & Gas Operator | Jun 2024 |
| 35 | Exxon Mobil Corporation | Spring, TX 77389 | Oil & Gas Operator | Oct 2025 |