| 1 | E Lyle Johnson Inc | Oklahoma City, OK 73142 | Oil & Gas Operator | Jun 2025 |
| 2 | Eagle Rock Mid-Continent Operating LLC | Tulsa, OK 74103-3703 | Oil & Gas Operator | Jun 2025 |
| 3 | Earlsboro Energies Corporation | Oklahoma City, OK 73116-3605 | Oil & Gas Operator | Jun 2025 |
| 4 | Edinger Engineering, Inc. | Oklahoma City, OK 73102 | Oil & Gas Operator | Jul 2025 |
| 5 | Edinger Inc. | Oklahoma City, OK 73102 | Oil & Gas Operator | Jun 2007 |
| 6 | Eec Inc | Norman, OK 73069-6344 | Oil & Gas Operator | Jun 2025 |
| 7 | Egolf Operating Company | Oklahoma City, OK 73114-7899 | Oil & Gas Operator | Apr 1998 |
| 8 | Ekg Operating Inc | Seminole, OK 74818-1028 | Oil & Gas Operator | Nov 2015 |
| 9 | El Paso Production Company | Houston, TX 77002 | Oil & Gas Operator | Mar 2016 |
| 10 | Eland Energy Inc | Dallas, TX 75248 | Oil & Gas Operator | Jul 2025 |
| 11 | Elder & Vaughn Inc | Oklahoma City, OK 73154-0938 | Oil & Gas Operator | Mar 2008 |
| 12 | Elite Tank Trucks, Inc | | Oil & Gas Operator | Jul 2025 |
| 13 | Encore Operating Inc | Edmond, OK 73013-5417 | Oil Operator | Jun 2025 |
| 14 | Endevco Eureka LLC | Oklahoma City, OK 73102-9211 | Oil & Gas Operator | Apr 2014 |
| 15 | Enerfin Resources I Limited Partnership | Houston, TX 77077-2386 | Oil & Gas Operator | Apr 2023 |
| 16 | Energas Corporation | Oklahoma City, OK 73105 | Oil & Gas Operator | Jun 2025 |
| 17 | Enersource Royalty Corporation | Oklahoma City, OK 73102 | Oil & Gas Operator | May 2013 |
| 18 | Enervest Operating LLC | Houston, TX 77002 | Oil & Gas Operator | Oct 2025 |
| 19 | Enterprising Enterprises Inc | Tulsa, OK 74137 | Oil Operator | Jun 2009 |
| 20 | EOG (Oklahoma) Inc. | Oklahoma City, OK 73112 | Oil & Gas Operator | Oct 2016 |
| 21 | EP Operating LP | Dallas, TX 75201 | Oil & Gas Operator | Mar 2015 |
| 22 | Esenjay Exploration, Inc | Houston, TX 77042 | Oil & Gas Operator | Jun 2025 |
| 23 | Esis Inc | | Oil & Gas Operator | Feb 2017 |
| 24 | Estoril Producing Corporation | Midland, TX 79701 | Oil & Gas Operator | Apr 1994 |
| 25 | Excelco Energy Inc. | Kingwood, TX 77339 | Oil & Gas Operator | Jul 2018 |
| 26 | Exxon Mobil Corporation | Spring, TX 77389 | Oil & Gas Operator | Oct 2025 |