| 1 | A T M Corporation | Mathis, TX 78368 | Oil & Gas Operator | Oct 2002 |
| 2 | A.O.E. Operators, Inc. | Fulshear, TX 77441 | Oil & Gas Operator | Oct 2025 |
| 3 | Abaco Operating, LLC | San Antonio, TX 78209 | Oil & Gas Operator | Oct 2025 |
| 4 | Abraxas Petroleum Corporation | San Antonio, TX 78259 | Oil & Gas Operator | Oct 2025 |
| 5 | Abraxas Production Corporation | San Antonio, TX 78270 | Oil & Gas Operator | Sep 1999 |
| 6 | Acock/Anaqua Operating Co., LP | Corpus Chrsti, TX 78401 | Oil & Gas Operator | Oct 2025 |
| 7 | Alamo Operating Company, L. C. | San Antonio, TX 78278 | Oil & Gas Operator | Aug 2023 |
| 8 | Alaron Energy, Inc. | Irving, TX 75038 | Oil & Gas Operator | Oct 2025 |
| 9 | Allegro Investments, Inc. | Victoria, TX 77903 | Oil & Gas Operator | Nov 2020 |
| 10 | Allen & Shumate, Inc. | Alice, TX 78333 | Oil & Gas Operator | Jan 1996 |
| 11 | American Cometra, Inc. | Fort Worth, TX 76102 | Oil & Gas Operator | Mar 2008 |
| 12 | American Shoreline, Inc. | Corpus Chrsti, TX 78401 | Oil & Gas Operator | Oct 2025 |
| 13 | Amoco Production Co. | Houston, TX 77253 | Oil & Gas Operator | Jun 2015 |
| 14 | Anadarko E&P Company LP | Houston, TX 77251 | Oil & Gas Operator | Aug 2014 |
| 15 | Anderson Oil Corporation | Corpus Chrsti, TX 78403 | Oil & Gas Operator | Nov 1999 |
| 16 | Anderson Oil LTD. | Corpus Chrsti, TX 78401 | Oil & Gas Operator | Oct 2025 |
| 17 | Anr Production Company | Houston, TX 77046 | Oil & Gas Operator | Aug 2017 |
| 18 | Apache Corporation | Houston, TX 77042 | Oil & Gas Operator | Oct 2025 |
| 19 | Aransas DRLG & Workover Co Inc | Corpus Chrsti, TX 78409 | Oil & Gas Operator | Jul 2019 |
| 20 | Arch Petroleum Inc. | Houston, TX 77252 | Oil & Gas Operator | Mar 2008 |
| 21 | Aroc (Texas) Inc | Houston, TX 77090 | Oil & Gas Operator | Dec 2014 |
| 22 | Arrington,David H. Oil & Gas,Inc | Midland, TX 79702 | Oil & Gas Operator | Oct 2025 |
| 23 | Atasca Resources Inc | Houston, TX 77219 | Oil & Gas Operator | Oct 2025 |
| 24 | Aurora Resources Corporation | Corpus Chrsti, TX 78401 | Oil & Gas Operator | Oct 2025 |
| 25 | Austin Energy Operations, Inc. | Corpus Chrsti, TX 78410 | Oil & Gas Operator | Oct 2025 |
| 26 | Austin Resources Corporation | Houston, TX 77027 | Oil & Gas Operator | Mar 2008 |
| 27 | Axio Production Company, L.P. | Tulsa, OK 74103 | Oil & Gas Operator | Jan 2006 |