| 1 | Acadian Gas Pipeline System | | Oil Operator | Jan 2024 |
| 2 | Acadiana Reserves, Inc. | | Oil & Gas Operator | Oct 1984 |
| 3 | Aldine Oil And Gas, LP | Houston, TX 77060 | Oil & Gas Operator | May 2024 |
| 4 | Allied-Gulf Energy, LLC | Lafayette, LA 70508 | Oil & Gas Operator | May 2024 |
| 5 | Alta Mesa Services, LP | Houston, TX 77084 | Oil & Gas Operator | May 2024 |
| 6 | Amax Oil & Gas Inc | Fort Worth, TX 76107 | Oil & Gas Operator | Nov 2014 |
| 7 | Amerada Hess Corporation | Houston, TX 77252 | Oil & Gas Operator | Aug 2013 |
| 8 | American Exploration Company | Houston, TX 77010 | Oil & Gas Operator | Jan 2000 |
| 9 | American Exploration Oper. Co. | | Oil & Gas Operator | May 1990 |
| 10 | American Explorer, Inc. | Lafayette, LA 70505 | Oil & Gas Operator | Jan 1999 |
| 11 | American Petrofina Co Of Texas | | Oil & Gas Operator | Jun 1985 |
| 12 | Aminoil Of Louisiana, Inc. | | Oil & Gas Operator | Dec 1981 |
| 13 | Aminoil USA Inc | | Oil & Gas Operator | Jan 1985 |
| 14 | Amoco Production Co. | Houston, TX 77253 | Oil & Gas Operator | Jun 2015 |
| 15 | Anadarko E&P Company LP | Houston, TX 77251 | Oil & Gas Operator | Aug 2014 |
| 16 | Anadarko Petroleum Corporation | Houston, TX 77251 | Oil & Gas Operator | Jan 2024 |
| 17 | Apache Corporation | Houston, TX 77056 | Oil & Gas Operator | May 2024 |
| 18 | Apache Energy Resources Corp | Houston, TX 77056 | Oil & Gas Operator | Mar 2015 |
| 19 | Apd Company | | Oil & Gas Operator | Apr 1987 |
| 20 | Aquila Energy Resources Corp. | Houston, TX 77042 | Oil & Gas Operator | Nov 2013 |
| 21 | Aroc (Texas) Inc | Houston, TX 77090 | Oil & Gas Operator | Dec 2014 |
| 22 | Array Operating, LLC | | Oil & Gas Operator | Mar 2017 |
| 23 | Ashland Exploration Inc | Houston, TX 77218 | Oil & Gas Operator | Nov 2000 |
| 24 | Ashland Oil, Inc | | Oil & Gas Operator | Dec 2022 |
| 25 | Aspect Energy, LLC | Denver, CO 80202 | Oil & Gas Operator | May 2024 |
| 26 | Atlas Production Services | | Oil & Gas Operator | Feb 1999 |
| 27 | Austral Oil Company Incorporated | Sulphur, LA 70663 | Oil & Gas Operator | Mar 2008 |