| 1 | Adventure Operating Company, LLC | Midland, TX 79702 | Oil & Gas Operator | Jan 2021 |
| 2 | Aeg Operating, LLC | Austin, TX 78746 | Oil Operator | Jun 2012 |
| 3 | Aghorn Operating, Inc. | Odessa, TX 79768 | Oil & Gas Operator | Oct 2025 |
| 4 | Ajax Resources, LLC | Houston, TX 77046 | Oil & Gas Operator | Oct 2025 |
| 5 | Alegre Energy Operating, LP | San Antonio, TX 78216 | Oil & Gas Operator | Sep 2005 |
| 6 | Alegre Energy, Inc. | San Antonio, TX 78216 | Oil & Gas Operator | Oct 2025 |
| 7 | Alpine Resources, Inc. | Houston, TX 77002 | Oil & Gas Operator | Mar 2008 |
| 8 | Altura Energy LTD. | Houston, TX 77210 | Oil & Gas Operator | Apr 2000 |
| 9 | Amax Oil & Gas Inc | Fort Worth, TX 76107 | Oil & Gas Operator | Nov 2014 |
| 10 | Amcon Resources, Inc. | Oklahoma City, OK 73101 | Gas Operator | Jun 2016 |
| 11 | Amerada Hess Corporation | Houston, TX 77252 | Oil & Gas Operator | Aug 2013 |
| 12 | American Exploration Company | Houston, TX 77010 | Oil & Gas Operator | Jan 2000 |
| 13 | American Star Energy & Min. Corp | Katy, TX 77449 | Oil & Gas Operator | Oct 2025 |
| 14 | Amerind Oil Company, LTD. | Midland, TX 79701 | Oil & Gas Operator | Nov 2004 |
| 15 | Amirmex Inc. | Denver, CO 80234 | Oil & Gas Operator | Oct 2025 |
| 16 | Ammonite Energy Texas, Inc. | Midland, TX 79710 | Oil & Gas Operator | Aug 2003 |
| 17 | Amoco Production Co. | Houston, TX 77253 | Oil & Gas Operator | Jun 2015 |
| 18 | Amtex Energy, Inc. | Fort Worth, TX 76147 | Oil & Gas Operator | Oct 2025 |
| 19 | Anadarko E&P Onshore LLC | Houston, TX 77046 | Oil & Gas Operator | Oct 2025 |
| 20 | Anadarko Petroleum Corporation | Houston, TX 77251 | Oil & Gas Operator | Jul 2025 |
| 21 | Anschutz Exploration Corporation | Denver, CO 80202 | Oil & Gas Operator | Oct 2025 |
| 22 | Antelope Energy Company LLC | Denver, CO 80202 | Oil & Gas Operator | Dec 2024 |
| 23 | Antelope Production Co. | Midland, TX 79701 | Oil & Gas Operator | Oct 1995 |
| 24 | Anthony, Bob G. Inc. | Brookhaven, MS 39601 | Oil & Gas Operator | Oct 2025 |
| 25 | Aoco Operating Company, L.L.C. | Houston, TX 77008 | Oil & Gas Operator | Feb 2005 |
| 26 | Aoco Operating, L.P. | Houston, TX 77008 | Oil & Gas Operator | Mar 2008 |
| 27 | Apache Corporation | Houston, TX 77042 | Oil & Gas Operator | Oct 2025 |
| 28 | Apache Energy Resources Corp | Houston, TX 77056 | Oil & Gas Operator | Mar 2015 |
| 29 | Apex Royalties, Inc. | Midland, TX 79702 | Oil & Gas Operator | May 1997 |
| 30 | Arch Oil & Gas, LLC | Dallas, TX 75254 | Oil & Gas Operator | Oct 2025 |
| 31 | Arch Petroleum Inc. | Houston, TX 77252 | Oil & Gas Operator | Mar 2008 |
| 32 | Arco Oil & Gas Company | Plano, TX 75086 | Oil & Gas Operator | Mar 2006 |
| 33 | Arco Permian | Houston, TX 77079 | Oil & Gas Operator | Dec 2001 |
| 34 | Ard Drilling Company Inc. | Abilene, TX 79604 | Oil & Gas Operator | Jun 2000 |
| 35 | Ares Energy, LTD. | Midland, TX 79701 | Oil & Gas Operator | Oct 2025 |
| 36 | Aries Operating LP | Houston, TX 77042 | Oil & Gas Operator | Oct 2025 |
| 37 | Aries Operating, LLC | Houston, TX 77010 | Oil & Gas Operator | Feb 2010 |
| 38 | Aroc (Texas) Inc | Houston, TX 77090 | Oil & Gas Operator | Dec 2014 |
| 39 | Arrington,David H. Oil & Gas,Inc | Midland, TX 79702 | Oil & Gas Operator | Oct 2025 |
| 40 | Aspen Exploration, Inc. | Houston, TX 77002 | Oil & Gas Operator | Dec 2012 |
| 41 | Aspen Operating Company LLC | Fort Worth, TX 76116 | Oil & Gas Operator | Oct 2025 |
| 42 | Atapco | Houston, TX 77040 | Oil & Gas Operator | Feb 1999 |
| 43 | Atlas Operating LLC | Houston, TX 77056 | Oil & Gas Operator | Oct 2025 |
| 44 | Aviara Energy Corporation | Dallas, TX 75201 | Oil & Gas Operator | Jun 2002 |
| 45 | Avra Oil Co | Dallas, TX 75248 | Oil & Gas Operator | Oct 2025 |
| 46 | Axis Energy Corporation | Roswell, NM 88202 | Oil & Gas Operator | Oct 2025 |