| 1 | Abaco Operating, LLC | San Antonio, TX 78209 | Oil & Gas Operator | Oct 2025 |
| 2 | Abraxas Petroleum Corporation | San Antonio, TX 78259 | Oil & Gas Operator | Oct 2025 |
| 3 | Acock Engineering & Assoc., Inc. | Corpus Chrsti, TX 78401 | Oil & Gas Operator | Jul 2002 |
| 4 | Acock Operating Limited | San Antonio, TX 78270 | Oil & Gas Operator | Oct 2025 |
| 5 | Acock/Anaqua Operating Co., LC | Corpus Chrsti, TX 78401 | Oil & Gas Operator | Apr 2004 |
| 6 | Acock/Anaqua Operating Co., LP | Corpus Chrsti, TX 78401 | Oil & Gas Operator | Oct 2025 |
| 7 | Ageron Energy, LLC | San Antonio, TX 78209 | Oil & Gas Operator | Oct 2025 |
| 8 | Akers, Bill | Hebbronville, TX 78361 | Oil & Gas Operator | Aug 2003 |
| 9 | Alaron Energy, Inc. | Irving, TX 75038 | Oil & Gas Operator | Oct 2025 |
| 10 | Alco DRLG. Co. | Freer, TX 78357 | Oil & Gas Operator | Oct 2025 |
| 11 | Aldine Oil And Gas, LP | Houston, TX 77060 | Oil & Gas Operator | Oct 2025 |
| 12 | Alegre Energy Operating, LP | San Antonio, TX 78216 | Oil & Gas Operator | Sep 2005 |
| 13 | Alegre Energy, Inc. | San Antonio, TX 78216 | Oil & Gas Operator | Oct 2025 |
| 14 | Alyndson Oil & Gas Inc. | Alice, TX 78333 | Oil & Gas Operator | Jun 2000 |
| 15 | Ambrit Energy Corporation | Garland, TX 75044 | Oil & Gas Operator | Jun 2003 |
| 16 | American Exploration Company | Houston, TX 77010 | Oil & Gas Operator | Jan 2000 |
| 17 | Amoco Production Co. | Houston, TX 77253 | Oil & Gas Operator | Jun 2015 |
| 18 | Amplify Energy Operating LLC | Houston, TX 77002 | Oil & Gas Operator | Oct 2025 |
| 19 | Anadarko E&P Company LP | Houston, TX 77251 | Oil & Gas Operator | Aug 2014 |
| 20 | Anadarko E&P Onshore LLC | Houston, TX 77046 | Oil & Gas Operator | Oct 2025 |
| 21 | Antara Resources Inc | Houston, TX 77002 | Oil & Gas Operator | Apr 2004 |
| 22 | Apache Corporation | Houston, TX 77042 | Oil & Gas Operator | Oct 2025 |
| 23 | Arco Oil & Gas Company | Plano, TX 75086 | Oil & Gas Operator | Mar 2006 |
| 24 | Arete Operating Company II, LLC | San Antonio, TX 78260 | Oil & Gas Operator | Oct 2025 |
| 25 | Arete Operating Company III, LLC | San Antonio, TX 78260 | Oil & Gas Operator | Oct 2025 |
| 26 | Arete Operating Company, LLC | San Antonio, TX 78260 | Oil & Gas Operator | Oct 2025 |
| 27 | Asher Resources | Boerne, TX 78006 | Oil & Gas Operator | May 2015 |
| 28 | Atasca Resources Inc | Houston, TX 77219 | Oil & Gas Operator | Oct 2025 |
| 29 | Atinum Operating, Inc. | Houston, TX 77002 | Oil & Gas Operator | Oct 2025 |
| 30 | Austin Resources Corporation | Houston, TX 77027 | Oil & Gas Operator | Mar 2008 |
| 31 | Austin Resources Oper Company | Houston, TX 77019 | Gas Operator | Mar 1999 |
| 32 | Auten Operating Company, Inc. | Houston, TX 77242 | Oil & Gas Operator | May 1998 |
| 33 | Awp Operating Company | George West, TX 78022 | Oil & Gas Operator | Oct 2025 |
| 34 | Axio Production Company, L.P. | Tulsa, OK 74103 | Oil & Gas Operator | Jan 2006 |