| 1 | A.E.N. Energy | Abilene, TX 79608 | Oil & Gas Operator | Feb 2005 |
| 2 | A.E.N. Energy, Inc. | Abilene, TX 79608 | Oil & Gas Operator | Jan 1996 |
| 3 | Abernathy Exploration Company | Abilene, TX 79608 | Oil & Gas Operator | Mar 2002 |
| 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 | Adams Branch Exploration Company | Abilene, TX 79608 | Oil & Gas Operator | Jul 2002 |
| 7 | Adkins, R. L. Corp. | Lubbock, TX 79408 | Oil & Gas Operator | Jun 2013 |
| 8 | Aethon I LP | Dallas, TX 75206 | Oil & Gas Operator | Mar 2015 |
| 9 | Alaron Energy, Inc. | Irving, TX 75038 | Oil & Gas Operator | Oct 2025 |
| 10 | Alegre Energy, Inc. | San Antonio, TX 78216 | Oil & Gas Operator | Oct 2025 |
| 11 | Alexander Energy Corporation | Dallas, TX 75206 | Oil & Gas Operator | Apr 2015 |
| 12 | Alexander Resources, Inc. | Abilene, TX 79608 | Oil & Gas Operator | Oct 2025 |
| 13 | Allison Lease Services LLC | Boerne, TX 78006 | Oil & Gas Operator | Oct 2025 |
| 14 | Amerac Energy Corporation | Tulsa, OK 74136 | Oil & Gas Operator | Jun 2013 |
| 15 | Amerada Hess Corporation | Houston, TX 77252 | Oil & Gas Operator | Aug 2013 |
| 16 | Anadarko Petroleum Corporation | Houston, TX 77251 | Oil & Gas Operator | Jul 2025 |
| 17 | Anderson, James K. Inc. | Abilene, TX 79608 | Oil & Gas Operator | Oct 2025 |
| 18 | Apex Royalties, Inc. | Midland, TX 79702 | Oil & Gas Operator | May 1997 |
| 19 | Argee Oil Company | Midland, TX 79702 | Gas Operator | May 1994 |
| 20 | Argent Petroleum Corporation | Center, TX 75935 | Oil & Gas Operator | Oct 2025 |
| 21 | Atapco | Houston, TX 77040 | Oil & Gas Operator | Feb 1999 |
| 22 | Atlas Operating LLC | Houston, TX 77056 | Oil & Gas Operator | Oct 2025 |
| 23 | Avra Oil Co | Dallas, TX 75248 | Oil & Gas Operator | Oct 2025 |