| 1 | Ace Productions | Beaumont, TX 77707 | Oil & Gas Operator | Apr 2024 |
| 2 | Acock Operating Limited | San Antonio, TX 78270 | Oil & Gas Operator | Apr 2024 |
| 3 | Acock/Anaqua Operating Co., LP | Corpus Chrsti, TX 78401 | Oil & Gas Operator | Apr 2024 |
| 4 | Alegre Energy, Inc. | San Antonio, TX 78216 | Oil & Gas Operator | Apr 2024 |
| 5 | Allied Operating Texas, LLC | Kilgore, TX 75663 | Oil & Gas Operator | Apr 2024 |
| 6 | Allied-Gulf Energy, LLC | Lafayette, LA 70508 | Oil & Gas Operator | Apr 2024 |
| 7 | Alpine Resources, Inc. | Houston, TX 77002 | Oil & Gas Operator | Mar 2008 |
| 8 | Amerada Hess Corporation | Houston, TX 77252 | Oil & Gas Operator | Aug 2013 |
| 9 | American Coastal Energy, Inc. | Houston, TX 77225 | Oil & Gas Operator | May 2008 |
| 10 | American Exploration Company | Houston, TX 77010 | Oil & Gas Operator | Jan 2000 |
| 11 | American Operating Company | Kilgore, TX 75663 | Oil & Gas Operator | Oct 2003 |
| 12 | Americo Energy Resources, LLC | Houston, TX 77063 | Oil & Gas Operator | Apr 2024 |
| 13 | Amoco Production Co. | Houston, TX 77253 | Oil & Gas Operator | Jun 2015 |
| 14 | Anadarko Petroleum Corporation | Houston, TX 77251 | Oil & Gas Operator | Jan 2024 |
| 15 | Anloc, LLC | Houston, TX 77024 | Oil & Gas Operator | Apr 2019 |
| 16 | Antara Resources Inc | Houston, TX 77002 | Oil & Gas Operator | Apr 2004 |
| 17 | Apache Corporation | Houston, TX 77056 | Oil & Gas Operator | Apr 2024 |
| 18 | Arbol Resources, Inc. | Houston, TX 77079 | Oil & Gas Operator | Apr 2024 |
| 19 | Arco Oil & Gas Company | Plano, TX 75086 | Oil & Gas Operator | Mar 2006 |
| 20 | Arista Novelty, Inc. | Houston, TX 77256 | Oil & Gas Operator | Feb 1995 |
| 21 | Arkla Exploration Co. | Shreveport, LA 71151 | Oil & Gas Operator | Jan 1993 |
| 22 | Aspect Energy, LLC | Denver, CO 80202 | Oil & Gas Operator | Apr 2024 |
| 23 | Aspect Resources LLC | Denver, CO 80202 | Oil & Gas Operator | May 2002 |
| 24 | Atco Prod. Co., Inc. | Winnie, TX 77665 | Oil & Gas Operator | Nov 2020 |
| 25 | Auden Oil Inc. | Hardin, TX 77561 | Oil Operator | Apr 2024 |
| 26 | Austral Oil Company Incorporated | Sulphur, LA 70663 | Oil & Gas Operator | Mar 2008 |
| 27 | Axis Energy Corporation | Roswell, NM 88202 | Oil & Gas Operator | Apr 2024 |
| 28 | Azimuth Energy, LLC | Denver, CO 80203 | Oil & Gas Operator | Sep 2006 |