| 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 | Jul 2025 |
| 3 | D C Energy, Inc. | Oklahoma City, OK 73134 | Oil & Gas Operator | Apr 2020 |
| 4 | Dalen Resources Oil & Gas Co. | Dallas, TX 75206 | Oil & Gas Operator | Jun 2010 |
| 5 | Darnell Bobby J | Oklahoma City, OK 73112-8884 | Oil & Gas Operator | May 2025 |
| 6 | Darrell'S Drilling Inc | Konawa, OK 74849 | Oil Operator | Apr 2025 |
| 7 | David E Morgan Inc | Danville, CA 94506-2035 | Oil & Gas Operator | Apr 2025 |
| 8 | Davis Bros. Oil Producers, Inc. | Tulsa, OK 74119 | Oil & Gas Operator | Apr 2020 |
| 9 | Davis Operating Company | Elysian Field, TX 75642 | Oil & Gas Operator | Jul 2025 |
| 10 | Davis William H | Tulsa, OK 74103 | Oil & Gas Operator | Apr 2014 |
| 11 | Davon Drilling Company | Oklahoma City, OK 73113-0665 | Oil & Gas Operator | Mar 2015 |
| 12 | Dawson Geophysical Company | Midland, TX 79701 | Oil Operator | Aug 2024 |
| 13 | Daylight Petroleum LLC | Houston, TX 77052 | Oil & Gas Operator | Jul 2025 |
| 14 | DCP Operating Co LP | Houston, TX 77042 | Oil & Gas Operator | Apr 2025 |
| 15 | Deka Exploration Inc | Oklahoma City, OK 73113-0057 | Oil & Gas Operator | Nov 2019 |
| 16 | Delek Energy Systems Us Inc | Denver, CO 80202 | Oil & Gas Operator | Oct 2011 |
| 17 | Dette Oil Corporation | Oklahoma City, OK 73162-6249 | Oil & Gas Operator | Oct 2015 |
| 18 | Devon Energy Production Company LP | Oklahoma City, OK 73102 | Oil & Gas Operator | Jul 2025 |
| 19 | Devon Louisiana Corporation | Houston, TX 77002 | Oil & Gas Operator | Oct 2019 |
| 20 | Diamond A Inc. | Tulsa, OK 74137 | Oil & Gas Operator | Jun 2001 |
| 21 | Diamond Energy Operating Company | Tulsa, OK 74137 | Oil & Gas Operator | Mar 2005 |
| 22 | Digger Oil & Gas Inc | Prague, OK 74864 | Oil & Gas Operator | Mar 2025 |
| 23 | DKT Energy LLC | Edmond, OK 73083-6844 | Oil & Gas Operator | Sep 2014 |
| 24 | DLB Oil & Gas, Inc. | Big Lake, TX 76932 | Oil & Gas Operator | Jul 2025 |
| 25 | Doco Development Corporation | Norman, OK 73072 | Oil & Gas Operator | May 2025 |
| 26 | Dominion Ok TX E & P Inc | Oklahoma City, OK 73134 | Oil & Gas Operator | Nov 2018 |
| 27 | Donson Corporation | Edmond, OK 73083-0341 | Oil & Gas Operator | Jul 1997 |
| 28 | Draco Production Company | Tulsa, OK 74133 | Oil & Gas Operator | Jul 2012 |
| 29 | DSM Exploration Inc | Oklahoma City, OK 73154 | Oil & Gas Operator | May 1996 |
| 30 | Duncan Oil Properties, Inc. | Oklahoma City, OK 73102 | Oil & Gas Operator | Jul 2025 |
| 31 | Durango Exploration LLC | Oklahoma City, OK 73120-5309 | Oil & Gas Operator | May 2025 |