| 1 | Eason Production Company | Atlanta, TX 75551 | Oil & Gas Operator | May 2007 |
| 2 | East Texas Production MGT. Inc | Athens, TX 75751 | Oil & Gas Operator | Oct 2025 |
| 3 | Eastex Operating, Inc. | Tyler, TX 75701 | Oil & Gas Operator | Jun 2003 |
| 4 | Edmonds, Karl F. Inc. | Kilgore, TX 75663 | Oil & Gas Operator | Feb 2005 |
| 5 | Eex Corporation | Houston, TX 77060 | Oil & Gas Operator | Feb 2000 |
| 6 | El Paso E&P Company, L.P. | Houston, TX 77002 | Oil & Gas Operator | Mar 2013 |
| 7 | El Paso Production Company | Houston, TX 77002 | Oil & Gas Operator | Mar 2016 |
| 8 | Ellora LLC | Boulder, CO 80308 | Oil & Gas Operator | Feb 2010 |
| 9 | Elms Oil Company | Kilgore, TX 75663 | Oil & Gas Operator | Oct 2025 |
| 10 | Embassy Well Service, LLC | Carrollton, TX 75011 | Oil & Gas Operator | Oct 2025 |
| 11 | Enbridge Pipelines (Ne Texas) LP | Houston, TX 77002 | Oil & Gas Operator | Jan 2010 |
| 12 | Encore Operating LP | Plano, TX 75024 | Oil & Gas Operator | May 2025 |
| 13 | Energy 2000, Inc. | Reno, NV 89501 | Oil & Gas Operator | Oct 2025 |
| 14 | Enerquest Corporation | Kilgore, TX 75663 | Oil & Gas Operator | Oct 2025 |
| 15 | Enerquest Oil & Gas LLC | Oklahoma City, OK 73114 | Oil & Gas Operator | Jun 2025 |
| 16 | Enserch Exploration Inc | Dallas, TX 75206 | Oil & Gas Operator | Apr 2015 |
| 17 | Ensight Resources, L.L.C. | Shreveport, LA 71101 | Oil & Gas Operator | Apr 2001 |
| 18 | EOG Resources, Inc. | Midland, TX 79702 | Oil & Gas Operator | Oct 2025 |
| 19 | EP Operating Limited Partnership | Dallas, TX 75201 | Oil & Gas Operator | Feb 1995 |
| 20 | Eurovest Oil & Gas, Inc. | Graham, TX 76450 | Oil & Gas Operator | Mar 2008 |
| 21 | Ev Fleming Enterprises, LLC | Kilgore, TX 75662 | Oil & Gas Operator | Aug 2024 |
| 22 | Excel Oil & Gas, Inc. | Waxahachie, TX 75168 | Oil & Gas Operator | Oct 2025 |
| 23 | Exco Operating Company, LP | Dallas, TX 75251 | Oil & Gas Operator | Oct 2025 |
| 24 | Exco Partners Operating PTSHP LP | Dallas, TX 75251 | Oil & Gas Operator | Jan 2009 |
| 25 | Exco/Hgi JV Assets, LLC | Dallas, TX 75251 | Oil & Gas Operator | Jun 2014 |
| 26 | Exxon Corporation | Houston, TX 77210 | Oil & Gas Operator | Jun 2024 |
| 27 | Exxon Mobil Corporation | Spring, TX 77389 | Oil & Gas Operator | Oct 2025 |
| 28 | Exzena Oil Corp. | Tyler, TX 75713 | Oil & Gas Operator | Oct 2025 |