| 1 | D & G Oil & Gas Company Inc | Enid, OK 73702-2027 | Oil & Gas Operator | Nov 2021 |
| 2 | D & J Oil Company Of Okla Inc | Enid, OK 73706-0129 | Oil & Gas Operator | May 1999 |
| 3 | D & M Production Co Inc | Drumright, OK 74030 | Oil & Gas Operator | Jan 2025 |
| 4 | Damson Oil Corporation | Houston, TX 77210 | Oil & Gas Operator | Mar 2005 |
| 5 | Dana Petroleum Inc | Salt Lake City, UT 84047 | Oil & Gas Operator | Nov 1998 |
| 6 | Dance Oil Company | Denver, CO 80202 | Oil & Gas Operator | May 1993 |
| 7 | Darnell Bobby J | Oklahoma City, OK 73112-8884 | Oil & Gas Operator | Mar 2025 |
| 8 | Daube Company The | Ardmore, OK 73401 | Oil & Gas Operator | Apr 2025 |
| 9 | Daube Exploration Company | Ardmore, OK 73402 | Oil & Gas Operator | Nov 2020 |
| 10 | Davis Bros. Oil Producers, Inc. | Tulsa, OK 74119 | Oil & Gas Operator | Apr 2020 |
| 11 | Davis, William H. | Tulsa, OK 74103 | Oil & Gas Operator | Apr 2014 |
| 12 | Daylight Petroleum LLC | Houston, TX 77052 | Oil & Gas Operator | Jun 2025 |
| 13 | DCP Operating Co LP | Houston, TX 77042 | Oil & Gas Operator | Feb 2025 |
| 14 | Deck Oil Company | Tulsa, OK 74101 | Oil & Gas Operator | Jun 2020 |
| 15 | Delong Oil & Gas Services, Inc. | Cushing, OK 74023 | Oil & Gas Operator | Dec 2024 |
| 16 | Deminex U.S. Oil Company | | Oil & Gas Operator | Jan 1998 |
| 17 | Devon Energy Corp (Nevada) | Oklahoma City, OK 73102 | Oil & Gas Operator | Feb 2017 |
| 18 | Devon Energy Production Company LP | Oklahoma City, OK 73102 | Oil & Gas Operator | Jun 2025 |
| 19 | Dilley Corp | Yale, OK 74085 | Oil & Gas Operator | May 2013 |
| 20 | Dinsmore C E | Enid, OK 73702 | Oil & Gas Operator | May 2009 |
| 21 | Dixie Petroleum Inc | Cashion, OK 73016 | Oil & Gas Operator | May 2001 |
| 22 | DMS Investments Inc | Tulsa, OK 74132-2690 | Oil & Gas Operator | Mar 2015 |
| 23 | Dobbins Family Residual Trust | Ardmore, OK 73401 | Oil Operator | Jul 2008 |
| 24 | Dolphin Energy LLC | Lake Worth, FL 33467 | Oil & Gas Operator | Feb 2025 |
| 25 | Domac Oil Company Inc | Perkins, OK 74059-0642 | Oil & Gas Operator | Feb 2006 |
| 26 | Double Eagle Petroleum Corp | Evansville, IN 47725 | Oil & Gas Operator | Jun 2025 |
| 27 | Double H Petroleum Corporation | Tulsa, OK 74136-5414 | Oil & Gas Operator | May 2006 |
| 28 | Double R Petroleum | | Oil & Gas Operator | Sep 2004 |
| 29 | Drake Exploration Inc | Tulsa, OK 74105-4250 | Oil & Gas Operator | Mar 2025 |
| 30 | Dublin Petroleum Corporation | Enid, OK 73702-6029 | Oil & Gas Operator | Mar 2025 |
| 31 | Dundee Oil & Supply Inc | Tulsa, OK 74101 | Oil & Gas Operator | Apr 2001 |