| 1 | A & F Oil Company | | Oil & Gas Operator | Jan 2025 |
| 2 | A&K Production LLC Of Texas | | Oil & Gas Operator | Nov 2024 |
| 3 | A. J. Hodges, Ind. Inc Et Al | | Oil & Gas Operator | Jan 1979 |
| 4 | A. Michael Hyde Oil & Gas Co. | | Oil & Gas Operator | Jan 1989 |
| 5 | A.J. Hodges Industries, Inc. | | Oil & Gas Operator | Sep 1987 |
| 6 | Abraxas Petroleum Corporation | San Antonio, TX 78259 | Oil & Gas Operator | Oct 2025 |
| 7 | Aethon Energy Operating LLC | Dallas, TX 75251 | Oil & Gas Operator | Oct 2025 |
| 8 | American Exploration Company | Houston, TX 77010 | Oil & Gas Operator | Jan 2000 |
| 9 | American Quasar Petroleum Co. | Fort Worth, TX 76102 | Oil & Gas Operator | Apr 2014 |
| 10 | Amoco Production Co. | Houston, TX 77253 | Oil & Gas Operator | Jun 2015 |
| 11 | Amplify Energy Operating LLC | Houston, TX 77002 | Oil & Gas Operator | Oct 2025 |
| 12 | Anadarko E&P Company LP | Houston, TX 77251 | Oil & Gas Operator | Aug 2014 |
| 13 | Anadarko E&P Onshore LLC | Houston, TX 77046 | Oil & Gas Operator | Oct 2025 |
| 14 | Anadarko Petroleum Corporation | Houston, TX 77251 | Oil & Gas Operator | Jul 2025 |
| 15 | Apache Corporation | Houston, TX 77042 | Oil & Gas Operator | Oct 2025 |
| 16 | Arco O & G Co-Div Atl Rich Co | | Oil & Gas Operator | Feb 1994 |
| 17 | Ark-La-Tex Energy, L.L.C. | Shreveport, LA 71101 | Oil & Gas Operator | Oct 2025 |
| 18 | Arkla Energy Resources | Shreveport, LA 71151 | Oil & Gas Operator | Mar 2015 |
| 19 | Arkla Expl.Co & George E Woods | | Oil & Gas Operator | Dec 1992 |
| 20 | Arkla Exploration Co. | Shreveport, LA 71151 | Oil & Gas Operator | Jan 1993 |
| 21 | Art Machin & Associates, Inc. | | Oil & Gas Operator | Jul 1997 |
| 22 | Arthur Arnold | | Oil Operator | Dec 1991 |
| 23 | Arxana Oil & Gas Company, LLC | | Oil & Gas Operator | Jun 1998 |