| 1 | D & D Energy Inc | Sapulpa, OK 74066-8734 | Oil & Gas Operator | May 2013 |
| 2 | D & D Pipe & Equipment Inc | Kingfisher, OK 73750 | Oil & Gas Operator | Mar 2005 |
| 3 | D & J Oil Company | Kermit, TX 79745 | Oil & Gas Operator | Oct 2025 |
| 4 | D C Energy, Inc. | Oklahoma City, OK 73134 | Oil & Gas Operator | Apr 2020 |
| 5 | D.J.F. Services, Inc. | Holdenville, OK 74848 | Oil & Gas Operator | Oct 2025 |
| 6 | Dab Limited | Oklahoma City, OK 73116-9082 | Oil & Gas Operator | Aug 2013 |
| 7 | Dalen Resources Oil & Gas Co. | Dallas, TX 75206 | Oil & Gas Operator | Jun 2010 |
| 8 | Damson Oil Corporation | Houston, TX 77210 | Oil & Gas Operator | Mar 2005 |
| 9 | Davco Productions Inc | Springer, OK 73458-8191 | Oil & Gas Operator | Jun 2021 |
| 10 | Dawson Resources Inc | Franktown, CO 80116 | Oil & Gas Operator | Mar 2015 |
| 11 | DCP Operating Co LP | Houston, TX 77042 | Oil & Gas Operator | May 2025 |
| 12 | Dehart Company (The) | Ardmore, OK 73402 | Oil & Gas Operator | Jul 2025 |
| 13 | Derrick Resources Inc. | Henryetta, OK 74437-4249 | Oil & Gas Operator | Jun 2025 |
| 14 | Dette Oil Corporation | Oklahoma City, OK 73162-6249 | Oil & Gas Operator | Oct 2015 |
| 15 | Devon Energy Corp (Nevada) | Oklahoma City, OK 73102 | Oil & Gas Operator | Feb 2017 |
| 16 | Devon Energy Production Company LP | Oklahoma City, OK 73102 | Oil & Gas Operator | Oct 2025 |
| 17 | Devon Louisiana Corporation | Houston, TX 77002 | Oil & Gas Operator | Oct 2019 |
| 18 | Devon SFS Operating Inc | Oklahoma City, OK 73102 | Oil & Gas Operator | Mar 2008 |
| 19 | Dewey Energy GP LLC | Houston, TX 77002 | Oil & Gas Operator | Jun 2022 |
| 20 | Diamond Harry H Inc | Shawnee, OK 74801 | Oil & Gas Operator | Feb 2025 |
| 21 | Diamond Production Company LLC | Irving, TX 75016-7853 | Oil & Gas Operator | Jun 2025 |
| 22 | Dillingham Ranch LC | Tulsa, OK 74152 | Oil & Gas Operator | May 2013 |
| 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 | Dome Petroleum Corp | Denver, CO 80202 | Oil & Gas Operator | Dec 2016 |
| 26 | Dominion Exp Midcontinent Inc | Oklahoma City, OK 73134-2616 | Oil & Gas Operator | Oct 2024 |
| 27 | Dominion Exploration & Production Inc | Houston, TX 77060 | Oil & Gas Operator | Apr 2015 |
| 28 | Dominion Ok TX E & P Inc | Oklahoma City, OK 73134 | Oil & Gas Operator | Nov 2018 |
| 29 | Dorchester Resources LP | Oklahoma City, OK 73154-8879 | Oil & Gas Operator | Aug 2021 |
| 30 | Douglas Fairbanks Holdings LLC | Pine Hurst, TX 77362-9998 | Oil & Gas Operator | Jul 2025 |
| 31 | Duck Bros Dozer & Trucking Inc | Konawa, OK 74849 | Oil & Gas Operator | May 2025 |
| 32 | Duncan Oil Properties, Inc. | Oklahoma City, OK 73102 | Oil & Gas Operator | Oct 2025 |
| 33 | Dyco Petroleum Corporation | Tulsa, OK 74103 | Oil & Gas Operator | Mar 2015 |