| 1 | A & A Oil Company | Luling, TX 78648 | Oil & Gas Operator | Oct 2009 |
| 2 | A & A Tank Truck Company | Norman, OK 73070-8969 | Oil & Gas Operator | Jul 2025 |
| 3 | Abarr Trust (The) | Oklahoma City, OK 73179 | Oil & Gas Operator | Jul 2025 |
| 4 | Abraxas Petroleum Corporation | San Antonio, TX 78259 | Oil & Gas Operator | Oct 2025 |
| 5 | Action Petroleum Service Corp | Ardmore, OK 73401 | Oil Operator | Apr 2025 |
| 6 | Adams Resources Expl. Corp. | Houston, TX 77001 | Oil & Gas Operator | Apr 2020 |
| 7 | Adobe Oil & Gas Corporation | Midland, TX 79701 | Oil & Gas Operator | Jan 1993 |
| 8 | Aexco Petroleum Inc | Denver, CO 80202 | Oil & Gas Operator | Jul 2025 |
| 9 | Afo LLC | Velma, OK 73491 | Oil & Gas Operator | Dec 2024 |
| 10 | Alexander Energy Corporation | Dallas, TX 75206 | Oil & Gas Operator | Apr 2015 |
| 11 | Alexander Oil Co. | Loco, OK 73442-9409 | Oil & Gas Operator | Sep 2025 |
| 12 | Allen Oil & Gas LLC | Ardmore, OK 73401 | Oil Operator | Aug 2022 |
| 13 | Alligator Rock Well Service LLC | Velma, OK 73491-0627 | Oil & Gas Operator | Jul 2025 |
| 14 | Almont Energy LLC | Kingfisher, OK 73750-0901 | Oil & Gas Operator | Oct 2021 |
| 15 | Alpine Inc | Oklahoma City, OK 73134-2504 | Oil & Gas Operator | Feb 2024 |
| 16 | Amax Oil & Gas Inc | Fort Worth, TX 76107 | Oil & Gas Operator | Nov 2014 |
| 17 | Amerac Energy Corporation | Tulsa, OK 74136 | Oil & Gas Operator | Jun 2013 |
| 18 | American Natural Energy Corp | Oklahoma City, OK 73114 | Oil & Gas Operator | Jan 2025 |
| 19 | American Petroleum Corp | Addison, TX 75001 | Oil & Gas Operator | Oct 2025 |
| 20 | An-Son Corporation | Oklahoma City, OK 73124 | Oil & Gas Operator | Jan 2006 |
| 21 | Anadarko Basin Oil& Gas Lease Inc | Sayre, OK 73662 | Oil & Gas Operator | Jan 1997 |
| 22 | Anadarko E&P Onshore LLC | Houston, TX 77046 | Oil & Gas Operator | Oct 2025 |
| 23 | Anadarko Minerals Inc | Oklahoma City, OK 73102 | Oil & Gas Operator | Jul 2025 |
| 24 | Anadarko Petroleum Corporation | Houston, TX 77251 | Oil & Gas Operator | Jul 2025 |
| 25 | Anr Production Company | Houston, TX 77046 | Oil & Gas Operator | Aug 2017 |
| 26 | Anson Company | Oklahoma City, OK 73124 | Oil & Gas Operator | Apr 2018 |
| 27 | Antara Resources Inc | Houston, TX 77002 | Oil & Gas Operator | Apr 2004 |
| 28 | Apache Corporation | Houston, TX 77042 | Oil & Gas Operator | Oct 2025 |
| 29 | Apache Energy Resources Corp | Houston, TX 77056 | Oil & Gas Operator | Mar 2015 |
| 30 | Apache PHN North America, Inc. | | Oil & Gas Operator | Mar 2005 |
| 31 | Apc Operating Partnership LP | Tulsa, OK 74136-4224 | Oil & Gas Operator | Jun 2015 |
| 32 | Arbuckle Enterprises, Inc. | Edmond, OK 73083 | Oil & Gas Operator | Jun 2025 |
| 33 | Arcadia Oil Company | Edmond, OK 73013-9009 | Oil & Gas Operator | Oct 2015 |
| 34 | Arch Oil & Gas, LLC | Dallas, TX 75254 | Oil & Gas Operator | Oct 2025 |
| 35 | Arcotex Oil & Gas Inc | Gainesville, TX 76241-1357 | Oil & Gas Operator | Jul 2025 |
| 36 | Argee Oil Company | Midland, TX 79702 | Gas Operator | May 1994 |
| 37 | Aries Operating LP | Houston, TX 77042 | Oil & Gas Operator | Oct 2025 |
| 38 | Armstrong & McLeod Company | Okmulgee, OK 74447-0819 | Oil & Gas Operator | Dec 1993 |
| 39 | Arnold Oil Properties, Inc. | Oklahoma City, OK 73112 | Oil & Gas Operator | May 2019 |
| 40 | Arnold Oil Properties, L.L.C. | Nichols Hill, OK 73116 | Oil & Gas Operator | Oct 2025 |
| 41 | Arrow Energy, Incorporated | Houston, TX 77008 | Oil & Gas Operator | Jun 2025 |
| 42 | Aspen Energy Group, Inc. | Santa Ynez, CA 93460 | Oil & Gas Operator | Mar 2015 |
| 43 | Astro Corporation | Tulsa, OK 74145 | Oil & Gas Operator | Apr 2007 |
| 44 | Atkinson WM H Estate | Oklahoma City, OK 73156 | Oil & Gas Operator | Nov 2001 |
| 45 | Atlantic Richfield Company | Plano, TX 75074 | Oil & Gas Operator | Dec 2016 |
| 46 | Atlas Operating LLC | Houston, TX 77056 | Oil & Gas Operator | Oct 2025 |
| 47 | Avalanche Oil & Gas LLC | Kingfisher, OK 73750 | Oil & Gas Operator | Oct 2025 |
| 48 | Avalon Exploration Inc | Tulsa, OK 74119-5401 | Oil & Gas Operator | Dec 2019 |
| 49 | Aycox Robert D | Healdton, OK 73438 | Oil Operator | Sep 2022 |