| 1 | A J Ferguson | | Oil Operator | Apr 1988 |
| 2 | A. T. Teague, Jr. | | Oil Operator | Aug 1993 |
| 3 | Abco Petroleum Corp. | | Oil & Gas Operator | Jan 1999 |
| 4 | Acadian Land & Expl., Inc. | | Oil & Gas Operator | May 1992 |
| 5 | Achilles Oil, LLC | | Oil & Gas Operator | Sep 2024 |
| 6 | Aldridge Operating Co., LLC | | Oil & Gas Operator | Aug 2019 |
| 7 | Ambrit Energy Corporation | Garland, TX 75044 | Oil & Gas Operator | Jun 2003 |
| 8 | American Trading & Prod Corp | Houston, TX 77040-6471 | Oil & Gas Operator | Nov 2014 |
| 9 | Arbor Petroleum Corporation | Oklahoma City, OK 73102-4003 | Oil & Gas Operator | Mar 2011 |
| 10 | Arco O & G Co-Div Atl Rich Co | | Oil & Gas Operator | Feb 1994 |
| 11 | Arnold & Assoc-D&D-Coquina | | Oil Operator | Oct 1985 |
| 12 | Aspen Oil & Gas LLC | | Oil Operator | Jul 2014 |
| 13 | Atkins Production | | Oil Operator | Dec 2008 |
| 14 | Axis Onshore, LLC | | Oil & Gas Operator | Apr 2008 |
| 15 | Axis Onshore, LP | | Oil & Gas Operator | Dec 2010 |