| 1 | D & D Pipe & Equipment Inc | Kingfisher, OK 73750 | Oil & Gas Operator | Mar 2005 |
| 2 | D & J Oil Co | Kermit, TX 79745 | Oil & Gas Operator | Apr 2025 |
| 3 | D C Energy, Inc. | Oklahoma City, OK 73134 | Oil & Gas Operator | Apr 2020 |
| 4 | Daco, Inc. | Spearman, TX 79081 | Oil & Gas Operator | Apr 2025 |
| 5 | Dallas Production, Inc. | Dallas, TX 75206 | Oil & Gas Operator | Mar 2021 |
| 6 | Davco Productions Inc | Springer, OK 73458-8191 | Oil & Gas Operator | Jun 2021 |
| 7 | Davis Operating Company | Elysian Field, TX 75642 | Oil & Gas Operator | Apr 2025 |
| 8 | Davis William H | Tulsa, OK 74103 | Oil & Gas Operator | Apr 2014 |
| 9 | Dawson-Markwell Exploration Co. | Oklahoma City, OK 73101 | Oil & Gas Operator | Jan 2025 |
| 10 | DCP Operating Co LP | Houston, TX 77042 | Oil & Gas Operator | Jan 2025 |
| 11 | Dee-Jay Exploration Company | Nichols Hill, OK 73116 | Oil & Gas Operator | Apr 2025 |
| 12 | Denell Oil Corporation | Yukon, OK 73085 | Oil & Gas Operator | Jul 1994 |
| 13 | Derby Exploration LLC | Okc, OK 73102 | Oil & Gas Operator | Feb 2025 |
| 14 | Destin Corporation | Enid, OK 73702-2403 | Oil & Gas Operator | Mar 2005 |
| 15 | Dette Oil Corporation | Oklahoma City, OK 73162-6249 | Oil & Gas Operator | Oct 2015 |
| 16 | Devon Energy Corp (Nevada) | Oklahoma City, OK 73102 | Oil & Gas Operator | Feb 2017 |
| 17 | Devon Energy Production Company LP | Oklahoma City, OK 73102 | Oil & Gas Operator | Apr 2025 |
| 18 | Devon Gas Services, L.P. | Oklahoma City, OK 73102 | Oil & Gas Operator | Aug 2023 |
| 19 | Devon Louisiana Corporation | Houston, TX 77002 | Oil & Gas Operator | Oct 2019 |
| 20 | Dexxon, Inc. | Kiefer, OK 74041 | Oil & Gas Operator | Jan 2025 |
| 21 | Diversified Production LLC | Keithville, LA 71047 | Oil & Gas Operator | Apr 2025 |
| 22 | DLB Energy Corporation | Oklahoma City, OK 73118-1401 | Oil & Gas Operator | Dec 2014 |
| 23 | DMS Oil Company | Houston, TX 77042 | Oil & Gas Operator | Jan 2025 |
| 24 | Dominion Exp Midcontinent Inc | Oklahoma City, OK 73134-2616 | Oil & Gas Operator | Oct 2024 |
| 25 | Dominion Ok TX E & P Inc | Oklahoma City, OK 73134 | Oil & Gas Operator | Nov 2018 |
| 26 | Draco Production Company | Tulsa, OK 74133 | Oil & Gas Operator | Jul 2012 |
| 27 | Drake Exploration Inc | Tulsa, OK 74105-4250 | Oil & Gas Operator | Feb 2025 |
| 28 | DRG Energy Inc | Norman, OK 73026-3171 | Oil & Gas Operator | Jan 2025 |
| 29 | Duncan Oil Properties, Inc. | Oklahoma City, OK 73102 | Oil & Gas Operator | Apr 2025 |
| 30 | Durango Exploration LLC | Oklahoma City, OK 73120-5309 | Oil & Gas Operator | Feb 2025 |
| 31 | Dyco Petroleum Corporation | Tulsa, OK 74103 | Oil & Gas Operator | Mar 2015 |