| 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 | Dec 2025 |
| 3 | Dalen Resources Oil & Gas Co | Dallas, TX 75206 | Oil & Gas Operator | Jun 2010 |
| 4 | Dallas Production, Inc. | Dallas, TX 75206 | Oil & Gas Operator | Mar 2021 |
| 5 | Darnell Alma | Bristow, OK 74010 | Oil & Gas Operator | Jun 2000 |
| 6 | Daube Company The | Ardmore, OK 73401 | Oil & Gas Operator | Oct 2025 |
| 7 | Davco Productions Inc | Springer, OK 73458-8191 | Oil & Gas Operator | Jun 2021 |
| 8 | DCP Operating Co LP | Houston, TX 77042 | Oil & Gas Operator | Oct 2025 |
| 9 | DCP Production Company LLC | Dill City, OK 73641 | Gas Operator | Oct 2025 |
| 10 | Decalta International Corp | Denver, CO 80202 | Oil & Gas Operator | Mar 2015 |
| 11 | Deck Oil Company | Tulsa, OK 74101 | Oil & Gas Operator | Jun 2020 |
| 12 | Devon Energy Production Company, L.P. | Oklahoma City, OK 73102 | Oil & Gas Operator | Dec 2025 |
| 13 | Devon Louisiana Corporation | Houston, TX 77002 | Oil & Gas Operator | Oct 2019 |
| 14 | Di Energy Inc. | Houston, TX 77067 | Oil & Gas Operator | Jan 2004 |
| 15 | Diversified Production LLC | Keithville, LA 71047 | Oil & Gas Operator | Dec 2025 |
| 16 | DLB Energy Corporation | Oklahoma City, OK 73118-1401 | Oil & Gas Operator | Dec 2014 |
| 17 | Dominion Exp Midcontinent Inc | Oklahoma City, OK 73134-2616 | Oil & Gas Operator | Oct 2024 |
| 18 | Dominion Exploration & Production Inc | Houston, TX 77060 | Oil & Gas Operator | Apr 2015 |
| 19 | Dominion Ok TX E & P Inc | Oklahoma City, OK 73134 | Oil & Gas Operator | Nov 2018 |
| 20 | Dorchester Minerals Operating LP | Dallas, TX 75219 | Oil & Gas Operator | Jun 2022 |
| 21 | Dorchester Resources LP | Oklahoma City, OK 73154-8879 | Oil & Gas Operator | Aug 2021 |
| 22 | Draco Production Company | Tulsa, OK 74133 | Oil & Gas Operator | Jul 2012 |
| 23 | DRG Energy Inc. | Norman, OK 73026-3171 | Oil & Gas Operator | Sep 2025 |
| 24 | Duncan Jr J Walter | Oklahoma City, OK 73102 | Oil & Gas Operator | Dec 2016 |
| 25 | Duncan Oil Properties, Inc. | Oklahoma City, OK 73102 | Oil & Gas Operator | Dec 2025 |
| 26 | Dyco Petroleum Corporation | Tulsa, OK 74103 | Oil & Gas Operator | Mar 2015 |