| 1 | D & D Pipe & Equipment Inc | Kingfisher, OK 73750 | Oil & Gas Operator | Mar 2005 |
| 2 | D & G Oil & Gas Company Inc | Enid, OK 73702-2027 | Oil & Gas Operator | Nov 2021 |
| 3 | D & J Oil Company | Kermit, TX 79745 | Oil & Gas Operator | Oct 2025 |
| 4 | D & J Oil Company Of Okla Inc | Enid, OK 73706-0129 | Oil & Gas Operator | May 1999 |
| 5 | D C Energy, Inc. | Oklahoma City, OK 73134 | Oil & Gas Operator | Apr 2020 |
| 6 | Dalen Resources Oil & Gas Co. | Dallas, TX 75206 | Oil & Gas Operator | Jun 2010 |
| 7 | Dallas Production, Inc. | Dallas, TX 75206 | Oil & Gas Operator | Mar 2021 |
| 8 | Daube Company The | Ardmore, OK 73401 | Oil & Gas Operator | Jul 2025 |
| 9 | Dauco Petroleum Corporation | Rowlett, TX 75089-3066 | Oil & Gas Operator | Jan 2021 |
| 10 | Davis & Davis | | Oil & Gas Operator | Dec 2021 |
| 11 | Dawson Resources Inc | Franktown, CO 80116 | Oil & Gas Operator | Mar 2015 |
| 12 | Dawson-Markwell Exploration Co. | Oklahoma City, OK 73101 | Oil & Gas Operator | Jun 2025 |
| 13 | DCP Operating Co LP | Houston, TX 77042 | Oil & Gas Operator | May 2025 |
| 14 | Dehart Company (The) | Ardmore, OK 73402 | Oil & Gas Operator | Jul 2025 |
| 15 | Dennett'S Inc | Enid, OK 73701-1851 | Oil & Gas Operator | Apr 2014 |
| 16 | Derby Exploration LLC | Okc, OK 73102 | Oil & Gas Operator | Jul 2025 |
| 17 | Dette Oil Corporation | Oklahoma City, OK 73162-6249 | Oil & Gas Operator | Oct 2015 |
| 18 | Devon Energy Corp (Nevada) | Oklahoma City, OK 73102 | Oil & Gas Operator | Feb 2017 |
| 19 | Devon Energy Production Company LP | Oklahoma City, OK 73102 | Oil & Gas Operator | Oct 2025 |
| 20 | Devon Louisiana Corporation | Houston, TX 77002 | Oil & Gas Operator | Oct 2019 |
| 21 | Dewey Energy GP LLC | Houston, TX 77002 | Oil & Gas Operator | Jun 2022 |
| 22 | Dinsmore C E | Enid, OK 73702 | Oil & Gas Operator | May 2009 |
| 23 | Diversified Production LLC | Keithville, LA 71047 | Oil & Gas Operator | Oct 2025 |
| 24 | DLB Oil & Gas, Inc. | Big Lake, TX 76932 | Oil & Gas Operator | Oct 2025 |
| 25 | DMS Oil Company | Houston, TX 77042 | Oil & Gas Operator | Aug 2025 |
| 26 | Dome Petroleum Corp | Denver, CO 80202 | Oil & Gas Operator | Dec 2016 |
| 27 | Dominion Exp Midcontinent Inc | Oklahoma City, OK 73134-2616 | Oil & Gas Operator | Oct 2024 |
| 28 | Dominion Exploration & Production Inc | Houston, TX 77060 | Oil & Gas Operator | Apr 2015 |
| 29 | Dominion Ok TX E & P Inc | Oklahoma City, OK 73134 | Oil & Gas Operator | Nov 2018 |
| 30 | Dorchester Resources LP | Oklahoma City, OK 73154-8879 | Oil & Gas Operator | Aug 2021 |
| 31 | Double Eagle Petroleum Corp | Evansville, IN 47725 | Oil & Gas Operator | Oct 2025 |
| 32 | Draco Production Company | Tulsa, OK 74133 | Oil & Gas Operator | Jul 2012 |
| 33 | Dragon Energy LLC | Tulsa, OK 74135-7234 | Oil & Gas Operator | Feb 2015 |
| 34 | Duncan Oil & Gas Inc | Norman, OK 73072 | Oil & Gas Operator | Sep 2020 |
| 35 | Duncan Oil Properties, Inc. | Oklahoma City, OK 73102 | Oil & Gas Operator | Oct 2025 |
| 36 | Dune Resources Inc | Tulsa, OK 74103 | Oil & Gas Operator | Jan 1993 |
| 37 | Durango Exploration LLC | Oklahoma City, OK 73120-5309 | Oil & Gas Operator | Jul 2025 |
| 38 | Dyco Petroleum Corporation | Tulsa, OK 74103 | Oil & Gas Operator | Mar 2015 |