| 1 | A & D Exploration Company | Rockport, TX 78381 | Oil & Gas Operator | Oct 2025 |
| 2 | Abraxas Petroleum Corporation | San Antonio, TX 78259 | Oil & Gas Operator | Oct 2025 |
| 3 | Abraxas Production Corporation | San Antonio, TX 78270 | Oil & Gas Operator | Sep 1999 |
| 4 | Accidie Exploration And Dev.,Inc | Plano, TX 75023 | Oil & Gas Operator | Oct 2025 |
| 5 | Acock/Anaqua Operating Co., LP | Corpus Chrsti, TX 78401 | Oil & Gas Operator | Oct 2025 |
| 6 | Advantage Oil & Gas, Inc. | Pinehurst, TX 77362 | Oil & Gas Operator | Oct 2025 |
| 7 | Aikman Oil Corp. | Oklahoma City, OK 73157 | Oil & Gas Operator | Oct 2025 |
| 8 | Alaron Energy, Inc. | Irving, TX 75038 | Oil & Gas Operator | Oct 2025 |
| 9 | Allen, Mabel F. | Corpus Chrsti, TX 78412 | Oil & Gas Operator | Jul 2002 |
| 10 | Alliance Resources LLC | Midland, TX 79705 | Oil & Gas Operator | Oct 2025 |
| 11 | Alta Mesa Services, LP | Houston, TX 77084 | Oil & Gas Operator | Oct 2025 |
| 12 | American Cometra, Inc. | Fort Worth, TX 76102 | Oil & Gas Operator | Mar 2008 |
| 13 | American Exploration | Houston, TX 77010 | Gas Operator | Apr 1994 |
| 14 | American Exploration Company | Houston, TX 77010 | Oil & Gas Operator | Jan 2000 |
| 15 | American Shoreline, Inc. | Corpus Chrsti, TX 78401 | Oil & Gas Operator | Oct 2025 |
| 16 | Amerril Energy LLC | Houston, TX 77042 | Oil & Gas Operator | Oct 2025 |
| 17 | Amexco, LLC | San Antonio, TX 78259 | Oil & Gas Operator | Oct 2025 |
| 18 | Amoco Production Co. | Houston, TX 77253 | Oil & Gas Operator | Jun 2015 |
| 19 | Ampak Oil Company | Plano, TX 75074 | Oil & Gas Operator | Oct 2025 |
| 20 | Anadarko E&P Company LP | Houston, TX 77251 | Oil & Gas Operator | Aug 2014 |
| 21 | Anadarko Petroleum Corporation | Houston, TX 77251 | Oil & Gas Operator | Jul 2025 |
| 22 | Anderman/Smith Operating Company | Tulsa, OK 74136 | Oil & Gas Operator | Sep 1995 |
| 23 | Anderson Oil Corporation | Corpus Chrsti, TX 78403 | Oil & Gas Operator | Nov 1999 |
| 24 | Anderson Oil LTD. | Corpus Chrsti, TX 78401 | Oil & Gas Operator | Oct 2025 |
| 25 | Antara Resources Inc | Houston, TX 77002 | Oil & Gas Operator | Apr 2004 |
| 26 | Apache Corporation | Houston, TX 77042 | Oil & Gas Operator | Oct 2025 |
| 27 | Aransas DRLG & Workover Co Inc | Corpus Chrsti, TX 78409 | Oil & Gas Operator | Jul 2019 |
| 28 | Arco Oil & Gas Company | Plano, TX 75086 | Oil & Gas Operator | Mar 2006 |
| 29 | Arrington,David H. Oil & Gas,Inc | Midland, TX 79702 | Oil & Gas Operator | Oct 2025 |
| 30 | Atapco | Houston, TX 77040 | Oil & Gas Operator | Feb 1999 |
| 31 | Atasca Resources Inc | Houston, TX 77219 | Oil & Gas Operator | Oct 2025 |
| 32 | Austin Resources Corporation | Houston, TX 77027 | Oil & Gas Operator | Mar 2008 |
| 33 | Austral Oil Company Incorporated | Sulphur, LA 70663 | Oil & Gas Operator | Mar 2008 |
| 34 | Axis Energy Corporation | Roswell, NM 88202 | Oil & Gas Operator | Oct 2025 |