| 1 | E.G. Operating | Dallas, TX 75206 | Oil & Gas Operator | Mar 2008 |
| 2 | Eagle Oil & Gas Co. | Dallas, TX 75225 | Oil & Gas Operator | Oct 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 Operating, L.P. | Houston, TX 77060 | Oil & Gas Operator | Jul 2003 |
| 6 | El Paso E&P Company, L.P. | Houston, TX 77002 | Oil & Gas Operator | Mar 2013 |
| 7 | El Reno Energy, LLC | Granbury, TX 76048 | Oil & Gas Operator | Oct 2025 |
| 8 | Elliott Oil & Gas Company | The Woodlands, TX 77380 | Oil & Gas Operator | Sep 2006 |
| 9 | Elliott Oil & Gas Operating Co. | Magnolia, TX 77354 | Oil & Gas Operator | Oct 2025 |
| 10 | Encana Oil & Gas (USA) Inc. | Denver, CO 80202 | Oil & Gas Operator | Oct 2020 |
| 11 | Endeavor Energy Resources, LP | Midland, TX 79701 | Oil & Gas Operator | Mar 2025 |
| 12 | Endeavor Natural Gas, LP | Houston, TX 77002 | Oil & Gas Operator | Oct 2025 |
| 13 | Enercorp Resources, Inc. | Houston, TX 77027 | Oil & Gas Operator | Dec 1993 |
| 14 | Energy Development Corporation | Houston, TX 77067 | Oil & Gas Operator | Dec 2024 |
| 15 | Energy Transfer Crude Marketing LLC | Dallas, TX 75225 | Oil Operator | May 2025 |
| 16 | Enerquest Oil & Gas LLC | Oklahoma City, OK 73114 | Oil & Gas Operator | Jun 2025 |
| 17 | Enervest Operating LLC | Houston, TX 77002 | Oil & Gas Operator | Oct 2025 |
| 18 | Enhanced Energy Partners Corp | Tomball, TX 77377 | Oil & Gas Operator | Oct 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 | Enserch Oil & Gas, Inc. | Dallas, TX 75206 | Oil & Gas Operator | Mar 1998 |
| 22 | EOG Resources, Inc. | Midland, TX 79702 | Oil & Gas Operator | Oct 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 | Escoba Royalty Corporation | San Antonio, TX 78217 | Oil & Gas Operator | Nov 2005 |
| 26 | Esenjay Petroleum Corp. | Corpus Chrsti, TX 78471 | Oil & Gas Operator | Jul 1998 |
| 27 | Etoco Incorporated | Houston, TX 77002 | Oil & Gas Operator | May 2005 |
| 28 | Everest Minerals Corp. | Corpus Chrsti, TX 78403 | Oil & Gas Operator | Apr 2001 |
| 29 | Everest Resource Company | Corpus Chrsti, TX 78403 | Oil & Gas Operator | Oct 2025 |
| 30 | Export Petroleum Corporation | Fort Worth, TX 76147 | Oil & Gas Operator | Oct 2025 |
| 31 | Express Oil Co. | Hallettsville, TX 77964 | Oil & Gas Operator | Oct 2025 |
| 32 | Exxon Corporation | Houston, TX 77210 | Oil & Gas Operator | Jun 2024 |