| 1 | D & D Pipe & Equipment Inc | Kingfisher, OK 73750 | Oil & Gas Operator | Mar 2005 |
| 2 | D & J Oil Company | Kermit, TX 79745 | Oil & Gas Operator | Jun 2025 |
| 3 | D C Energy, Inc. | Oklahoma City, OK 73134 | Oil & Gas Operator | Apr 2020 |
| 4 | D-Mil Production Inc | Argyle, TX 76226 | Oil & Gas Operator | Jun 2025 |
| 5 | D.J.F. Services, Inc. | Holdenville, OK 74848 | Oil & Gas Operator | Jun 2025 |
| 6 | Dabb Energy Company | Fort Worth, TX 76132 | Oil & Gas Operator | Aug 2020 |
| 7 | Dalcor Energy LLC | Duncan, OK 73534 | Oil & Gas Operator | Mar 2025 |
| 8 | Dalen Resources Oil & Gas Co. | Dallas, TX 75206 | Oil & Gas Operator | Jun 2010 |
| 9 | Dallas Production, Inc. | Dallas, TX 75206 | Oil & Gas Operator | Mar 2021 |
| 10 | Damson Oil Corporation | Houston, TX 77210 | Oil & Gas Operator | Mar 2005 |
| 11 | Daniel Resource Dev Inc | Tomball, TX 77375-8919 | Oil & Gas Operator | Oct 2009 |
| 12 | Davco Productions Inc | Springer, OK 73458-8191 | Oil & Gas Operator | Jun 2021 |
| 13 | Davis, William H. | Tulsa, OK 74103 | Oil & Gas Operator | Apr 2014 |
| 14 | Daylight Petroleum LLC | Houston, TX 77052 | Oil & Gas Operator | Jun 2025 |
| 15 | DCP Operating Co LP | Houston, TX 77042 | Oil & Gas Operator | Feb 2025 |
| 16 | Dead Horse Oil & Gas LLC | Skiatook, OK 74070-9343 | Oil & Gas Operator | Jun 2015 |
| 17 | Deka Exploration Inc | Oklahoma City, OK 73113-0057 | Oil & Gas Operator | Nov 2019 |
| 18 | Dernick Resources, Inc. | Dallas, TX 75204 | Oil & Gas Operator | Jan 2002 |
| 19 | Dette Oil Corporation | Oklahoma City, OK 73162-6249 | Oil & Gas Operator | Oct 2015 |
| 20 | Devon Energy Corp (Nevada) | Oklahoma City, OK 73102 | Oil & Gas Operator | Feb 2017 |
| 21 | Devon Energy Production Company LP | Oklahoma City, OK 73102 | Oil & Gas Operator | Jun 2025 |
| 22 | Devon Louisiana Corporation | Houston, TX 77002 | Oil & Gas Operator | Oct 2019 |
| 23 | Diamond A Inc. | Tulsa, OK 74137 | Oil & Gas Operator | Jun 2001 |
| 24 | Diamond Energy Operating Company | Tulsa, OK 74137 | Oil & Gas Operator | Mar 2005 |
| 25 | Dickerson Dennis | Velma, OK 73491 | Oil Operator | Feb 2025 |
| 26 | DLB Energy Corporation | Oklahoma City, OK 73118-1401 | Oil & Gas Operator | Dec 2014 |
| 27 | DLB Oil & Gas, Inc. | Big Lake, TX 76932 | Oil & Gas Operator | Jun 2025 |
| 28 | DLKB Operating LLC | Eufaula, OK 74432 | Gas Operator | Feb 2025 |
| 29 | DMS Oil Company | Houston, TX 77042 | Oil & Gas Operator | Mar 2025 |
| 30 | Dolphin Energy LLC | Lake Worth, FL 33467 | Oil & Gas Operator | Feb 2025 |
| 31 | Dominion Exp Midcontinent Inc | Oklahoma City, OK 73134-2616 | Oil & Gas Operator | Oct 2024 |
| 32 | Dominion Ok TX E & P Inc | Oklahoma City, OK 73134 | Oil & Gas Operator | Nov 2018 |
| 33 | Draco Production Company | Tulsa, OK 74133 | Oil & Gas Operator | Jul 2012 |
| 34 | Drummond, F F | | Oil Operator | Feb 2025 |
| 35 | Duncan Oil Properties, Inc. | Oklahoma City, OK 73102 | Oil & Gas Operator | Jun 2025 |
| 36 | Durango Energy Inc | Chickasha, OK 73023 | Oil Operator | Dec 1999 |
| 37 | Durango Exploration LLC | Oklahoma City, OK 73120-5309 | Oil & Gas Operator | Mar 2025 |
| 38 | Dyco Petroleum Corporation | Tulsa, OK 74103 | Oil & Gas Operator | Mar 2015 |