| 1 | Aberdeen Petroleum (USA) Inc. | Abilene, TX 79608 | Oil & Gas Operator | Sep 1994 |
| 2 | Abraxas Petroleum Corporation | San Antonio, TX 78259 | Oil & Gas Operator | Oct 2025 |
| 3 | Ace Productions | Beaumont, TX 77707 | Oil & Gas Operator | Oct 2025 |
| 4 | Acock Operating Limited | San Antonio, TX 78270 | Oil & Gas Operator | Oct 2025 |
| 5 | Acock/Anaqua Operating Co., LP | Corpus Chrsti, TX 78401 | Oil & Gas Operator | Oct 2025 |
| 6 | Ada Belle Oil & Gas Company | Sourlake, TX 77659 | Oil Operator | Dec 2023 |
| 7 | Adams Resources Expl. Corp. | Houston, TX 77001 | Oil & Gas Operator | Apr 2020 |
| 8 | Addison Oil, LLC | Addison, TX 75001 | Oil & Gas Operator | Mar 2013 |
| 9 | Adobe Energy, Inc. | The Woodlands, TX 77380 | Oil & Gas Operator | Nov 2004 |
| 10 | Advantagewon Oil, Us, Corp. | Batson, TX 77519 | Oil Operator | Dec 2019 |
| 11 | Aikman Oil Corp. | Oklahoma City, OK 73157 | Oil & Gas Operator | Oct 2025 |
| 12 | Allied-Gulf Energy, LLC | Lafayette, LA 70508 | Oil & Gas Operator | Oct 2025 |
| 13 | Alpine Resources, Inc. | Houston, TX 77002 | Oil & Gas Operator | Mar 2008 |
| 14 | Alta Mesa Services, LP | Houston, TX 77084 | Oil & Gas Operator | Oct 2025 |
| 15 | American Cascade Energy, Inc. | Barker, TX 77413 | Oil & Gas Operator | Oct 2025 |
| 16 | American Energy Sources, Inc. | Spring, TX 77388 | Oil & Gas Operator | Dec 2008 |
| 17 | Amoco Production Co. | Houston, TX 77253 | Oil & Gas Operator | Jun 2015 |
| 18 | Anderson Petro-Equipment, Inc. | Montgomery, TX 77356 | Oil & Gas Operator | Oct 2025 |
| 19 | Anderson Producing, Inc. | Houston, TX 77057 | Oil & Gas Operator | Sep 2013 |
| 20 | Apache Corporation | Houston, TX 77042 | Oil & Gas Operator | Oct 2025 |
| 21 | Aquila Energy Resources Corp. | Houston, TX 77042 | Oil & Gas Operator | Nov 2013 |
| 22 | Arco Oil & Gas Co.-Silsbee | Lafayette, LA 70505 | Oil & Gas Operator | Jul 1993 |
| 23 | Arco Oil & Gas Company | Plano, TX 75086 | Oil & Gas Operator | Mar 2006 |
| 24 | Aries Operating, LLC | Houston, TX 77010 | Oil & Gas Operator | Feb 2010 |
| 25 | Arista Novelty, Inc. | Houston, TX 77256 | Oil & Gas Operator | Feb 1995 |
| 26 | Aroc (Texas) Inc | Houston, TX 77090 | Oil & Gas Operator | Dec 2014 |
| 27 | Arrowhead Operating Inc. | Argyle, TX 76226 | Oil & Gas Operator | Oct 2025 |
| 28 | Atco Prod. Co., Inc. | Winnie, TX 77665 | Oil & Gas Operator | Nov 2020 |
| 29 | Atlas Operating LLC | Houston, TX 77056 | Oil & Gas Operator | Oct 2025 |
| 30 | Auden Oil Inc. | Hardin, TX 77561 | Oil Operator | Oct 2025 |
| 31 | Axis Energy Corporation | Roswell, NM 88202 | Oil & Gas Operator | Oct 2025 |