| 1 | E2 Operating LLC | Tulsa, OK 74135 | Oil & Gas Operator | Oct 2025 |
| 2 | Edisto Resources Corp | Houston, TX 77057 | Oil & Gas Operator | Oct 1999 |
| 3 | Edwards Petroleum Company | Houston, TX 77092 | Oil & Gas Operator | Aug 2003 |
| 4 | Ellsworth, H. P. O&G Properties | Corpus Chrsti, TX 78413 | Oil & Gas Operator | Oct 2025 |
| 5 | Embry Solutions, Inc. | Dallas, TX 75315 | Oil Operator | Oct 2025 |
| 6 | Emerald Operating Company | Plano, TX 75075 | Oil & Gas Operator | Aug 2025 |
| 7 | Empire Texas Operating LLC | The Woodlands, TX 77380 | Oil & Gas Operator | Oct 2025 |
| 8 | Encana Oil & Gas (USA) Inc. | Denver, CO 80202 | Oil & Gas Operator | Oct 2020 |
| 9 | Endeavor Energy Resources, LP | Midland, TX 79701 | Oil & Gas Operator | Mar 2025 |
| 10 | Endeavor Natural Gas, LP | Houston, TX 77002 | Oil & Gas Operator | Oct 2025 |
| 11 | Enercorp Resources, Inc. | Houston, TX 77027 | Oil & Gas Operator | Dec 1993 |
| 12 | Energy & Expl. PRTNRS Oper., LP | Fort Worth, TX 76147 | Oil & Gas Operator | Oct 2016 |
| 13 | Energy Transfer Crude Marketing LLC | Dallas, TX 75225 | Oil Operator | May 2025 |
| 14 | Enerquest Oil & Gas LLC | Oklahoma City, OK 73114 | Oil & Gas Operator | Jun 2025 |
| 15 | Enerquest Operating, LLC | Oklahoma City, OK 73114 | Oil & Gas Operator | Oct 2025 |
| 16 | Enervest Operating LLC | Houston, TX 77002 | Oil & Gas Operator | Oct 2025 |
| 17 | Engroup Resources, L.P. | Houston, TX 77002 | Oil & Gas Operator | Oct 2025 |
| 18 | EOG Resources, Inc. | Midland, TX 79702 | Oil & Gas Operator | Oct 2025 |
| 19 | Estate Oil & Gas Corp. | Dallas, TX 75206 | Oil & Gas Operator | Oct 2011 |
| 20 | Etc Texas Pipeline, LTD. | Dallas, TX 75225 | Oil Operator | Sep 2023 |
| 21 | Etoco Incorporated | Houston, TX 77002 | Oil & Gas Operator | May 2005 |
| 22 | Etx Energy, LLC | Tulsa, OK 74136 | Oil & Gas Operator | Oct 2022 |
| 23 | Exxon Corporation | Houston, TX 77210 | Oil & Gas Operator | Jun 2024 |
| 24 | Exxon Mobil Corporation | Spring, TX 77389 | Oil & Gas Operator | Oct 2025 |