| 1 | A & A Tank Truck Company | Norman, OK 73070-8969 | Oil & Gas Operator | May 2025 |
| 2 | A R W Exploration Corp | Stillwater, OK 74076 | Oil & Gas Operator | May 2013 |
| 3 | Abarr Trust (The) | Oklahoma City, OK 73179 | Oil & Gas Operator | May 2025 |
| 4 | Abraxas Petroleum Corporation | San Antonio, TX 78259 | Oil & Gas Operator | Jul 2025 |
| 5 | Adams Res & Energy Co | Houston, TX 77001-0844 | Oil & Gas Operator | Mar 2015 |
| 6 | Adobe Resources Corporation | Midland, TX 79701 | Oil & Gas Operator | Aug 2002 |
| 7 | Aexco Petroleum Inc | Denver, CO 80202 | Oil & Gas Operator | May 2025 |
| 8 | Aikman Brothers, LLC | Amarillo, TX 79109 | Oil & Gas Operator | Apr 2025 |
| 9 | Alexander Energy Corporation | Dallas, TX 75206 | Oil & Gas Operator | Apr 2015 |
| 10 | Altman Energy, Inc. | Tulsa, OK 74114 | Oil & Gas Operator | Jul 2025 |
| 11 | Amax Oil & Gas Inc | Fort Worth, TX 76107 | Oil & Gas Operator | Nov 2014 |
| 12 | Amerex Corporation | Edmond, OK 73013-1044 | Oil & Gas Operator | Apr 2020 |
| 13 | An-Son Corporation | Oklahoma City, OK 73124 | Oil & Gas Operator | Jan 2006 |
| 14 | Anadarko Petroleum Corporation | Houston, TX 77251 | Oil & Gas Operator | May 2025 |
| 15 | Angel Exploration Company | Oklahoma City, OK 73102-8868 | Oil & Gas Operator | Jan 2019 |
| 16 | Angel Exploration LLC | Oklahoma City, OK 73116-3603 | Oil & Gas Operator | May 2025 |
| 17 | Anr Production Company | Houston, TX 77046 | Oil & Gas Operator | Aug 2017 |
| 18 | Anson Company | Oklahoma City, OK 73124 | Oil & Gas Operator | Apr 2018 |
| 19 | Antioch Operating LLC | Dallas, TX 75206 | Oil & Gas Operator | May 2025 |
| 20 | Apache Corporation | Houston, TX 77042 | Oil & Gas Operator | Jul 2025 |
| 21 | Apache Energy Resources Corp | Houston, TX 77056 | Oil & Gas Operator | Mar 2015 |
| 22 | Apc Operating Partnership LP | Tulsa, OK 74136-4224 | Oil & Gas Operator | Jun 2015 |
| 23 | Arbor Petroleum Corporation | Oklahoma City, OK 73102-4003 | Oil & Gas Operator | Mar 2011 |
| 24 | Aries Operating LP | Houston, TX 77042 | Oil & Gas Operator | Jul 2025 |
| 25 | Arkoma Resources LLC | Henryetta, OK 74437 | Oil & Gas Operator | Apr 2025 |
| 26 | Arpel, Inc. | Oklahoma City, OK 73102 | Oil & Gas Operator | Apr 2014 |
| 27 | Arrington David Oil & Gas Inc | Midland, TX 79702-2071 | Oil & Gas Operator | Dec 2014 |
| 28 | Arrow Oil & Gas, LLC | Norman, OK 73070 | Oil & Gas Operator | Jul 2025 |
| 29 | Arrowhead Energy Inc | Edmond, OK 73013 | Oil & Gas Operator | May 2025 |
| 30 | Arvine Pipe & Supply Co Inc | Norman, OK 73069-8224 | Oil & Gas Operator | Jul 2015 |
| 31 | Ashland Exploration Inc | Houston, TX 77218 | Oil & Gas Operator | Nov 2000 |
| 32 | Aspen Energy Group, Inc. | Santa Ynez, CA 93460 | Oil & Gas Operator | Mar 2015 |
| 33 | Atchley Resources, Inc. | Oklahoma City, OK 73134 | Oil & Gas Operator | May 2025 |
| 34 | Atlas Operating LLC | Houston, TX 77056 | Oil & Gas Operator | Jul 2025 |
| 35 | Avalanche Oil & Gas LLC | Kingfisher, OK 73750 | Oil & Gas Operator | Jul 2025 |