| 1 | E & S Operating Company | Caddo, TX 76429 | Oil & Gas Operator | Feb 2018 |
| 2 | E.C. Hindman Oil And Gas | Graham, TX 76450 | Oil & Gas Operator | Mar 2025 |
| 3 | Eagleridge Operating, LLC | Dallas, TX 75219 | Oil & Gas Operator | Mar 2025 |
| 4 | Eastland Operating, L.L.C. | Ranger, TX 76470 | Oil & Gas Operator | Mar 2025 |
| 5 | Echo Production Inc | Graham, TX 76450 | Oil & Gas Operator | Mar 2025 |
| 6 | Echols Oil Company | Caddo, TX 76429 | Oil & Gas Operator | Jan 2012 |
| 7 | Echols Oil Company, L.L.C. | Caddo, TX 76429 | Oil & Gas Operator | Mar 2025 |
| 8 | Edington Oil Company | Albany, TX 76430 | Oil & Gas Operator | Aug 2006 |
| 9 | Eland Energy Inc | Dallas, TX 75248 | Oil & Gas Operator | Dec 2024 |
| 10 | Eldorado Oil And Gas, Inc. | Dallas, TX 75230 | Oil & Gas Operator | Nov 1995 |
| 11 | Energex Inc. | Abilene, TX 79604 | Oil & Gas Operator | Mar 2025 |
| 12 | Energy Transfer Crude Marketing LLC | Houston, TX 77002 | Oil Operator | Sep 2024 |
| 13 | Engas Corporation | Jacksboro, TX 76458 | Oil & Gas Operator | May 2008 |
| 14 | Enre Corp. | San Antonio, TX 78209 | Oil & Gas Operator | Mar 2005 |
| 15 | Enrich Oil Corporation | Abilene, TX 79604 | Oil & Gas Operator | Mar 2025 |
| 16 | Enserch Exploration Inc | Dallas, TX 75206 | Oil & Gas Operator | Apr 2015 |
| 17 | Enstar Energy, Inc. | Arlington, TX 76003 | Oil & Gas Operator | Mar 2025 |
| 18 | EOG Resources, Inc. | Midland, TX 79702 | Oil & Gas Operator | Mar 2025 |
| 19 | EP Operating Limited Partnership | Dallas, TX 75201 | Oil & Gas Operator | Feb 1995 |
| 20 | Ernmar Investments, Inc. | Edmond, OK 73083 | Oil & Gas Operator | Mar 2025 |
| 21 | Esenjay Petroleum Corp. | Corpus Chrsti, TX 78471 | Oil & Gas Operator | Jul 1998 |
| 22 | Estacado Energy, LLC | Iowa Park, TX 76367 | Oil & Gas Operator | Mar 2025 |
| 23 | Evarado Oil Company | Strawn, TX 76475 | Oil & Gas Operator | Mar 2025 |
| 24 | Ex-Cel Resources, LLC | Breckenridge, TX 76424 | Oil & Gas Operator | Mar 2025 |
| 25 | Exco Resources Inc | Dallas, TX 75251 | Oil & Gas Operator | Nov 2024 |
| 26 | Expanding Energy Corporation | New Braunfels, TX 78132 | Oil & Gas Operator | Mar 2008 |
| 27 | Expro Engineering, Inc. | Fort Worth, TX 76179 | Oil & Gas Operator | Mar 2025 |