| 1 | E2 Operating LLC | Tulsa, OK 74135 | Oil & Gas Operator | Oct 2025 |
| 2 | Eagle Energy Production LLC | Tulsa, OK 74136-1935 | Oil & Gas Operator | Mar 2020 |
| 3 | Eagle Oil & Gas Co. | Dallas, TX 75225 | Oil & Gas Operator | Oct 2025 |
| 4 | Earlsboro Energies Corporation | Oklahoma City, OK 73116-3605 | Oil & Gas Operator | Jun 2025 |
| 5 | Eddie'S Submersible Service Inc | Shawnee, OK 74801-5047 | Oil & Gas Operator | Mar 2015 |
| 6 | Edinger Engineering, Inc. | Oklahoma City, OK 73102 | Oil & Gas Operator | Jul 2025 |
| 7 | Edinger Inc. | Oklahoma City, OK 73102 | Oil & Gas Operator | Jun 2007 |
| 8 | Edwards & Leach Oil Company | Oklahoma City, OK 73114 | Oil & Gas Operator | Mar 2005 |
| 9 | Eec Inc | Norman, OK 73069-6344 | Oil & Gas Operator | Jun 2025 |
| 10 | Egolf Operating Company | Oklahoma City, OK 73114-7899 | Oil & Gas Operator | Apr 1998 |
| 11 | Endeavor Energy Resources, LP | Midland, TX 79701 | Oil & Gas Operator | Mar 2025 |
| 12 | Enerfin Resources I Limited Partnership | Houston, TX 77077-2386 | Oil & Gas Operator | Apr 2023 |
| 13 | Energy Operations Oklahoma LP | Houston, TX 77002-6785 | Oil & Gas Operator | Nov 2010 |
| 14 | Enervest Operating LLC | Houston, TX 77002 | Oil & Gas Operator | Oct 2025 |
| 15 | Enserch Exploration Inc | Dallas, TX 75206 | Oil & Gas Operator | Apr 2015 |
| 16 | Entex Petroleum, Inc. | Oklahoma City, OK 73113 | Oil & Gas Operator | Nov 1997 |
| 17 | EOG (Oklahoma) Inc. | Oklahoma City, OK 73112 | Oil & Gas Operator | Oct 2016 |
| 18 | EOG Resources, Inc. | Midland, TX 79702 | Oil & Gas Operator | Oct 2025 |
| 19 | Eott Energy Corporation | Oklahoma City, OK 73118 | Oil & Gas Operator | Dec 1995 |
| 20 | Escher Corporation | Oklahoma City, OK 73120 | Oil & Gas Operator | Jun 2025 |
| 21 | Esis Inc | | Oil & Gas Operator | Feb 2017 |
| 22 | Essex Energy Inc | Yukon, OK 73099-5126 | Oil & Gas Operator | Apr 2014 |
| 23 | Evergreen Operating Corp | Denver, CO 80202 | Oil & Gas Operator | Dec 2019 |
| 24 | Exok, Inc. | Oklahoma City, OK 73116 | Oil & Gas Operator | Jun 2025 |
| 25 | Exploration Associates II LLC | Oklahoma City, OK 73102-8815 | Oil & Gas Operator | Jan 2013 |
| 26 | Express Oil & Gas LLC | Oklahoma City, OK 73142-3017 | Oil & Gas Operator | Jun 2025 |