| 1 | D & B Oil Company | Graham, TX 76450 | Oil & Gas Operator | Dec 2025 |
| 2 | D & D Oil Company | Dayton, TX 77535 | Oil & Gas Operator | Dec 2025 |
| 3 | D C Energy, Inc. | Oklahoma City, OK 73134 | Oil & Gas Operator | Apr 2020 |
| 4 | Dab And Associates Inc | Crescent, OK 73028-0580 | Oil & Gas Operator | Nov 2014 |
| 5 | Dab Limited | Oklahoma City, OK 73116-9082 | Oil & Gas Operator | Aug 2013 |
| 6 | Dalcor Energy LLC | Duncan, OK 73534 | Oil & Gas Operator | Aug 2025 |
| 7 | Dalen Resources Oil & Gas Co | Dallas, TX 75206 | Oil & Gas Operator | Jun 2010 |
| 8 | Dallas Production, Inc. | Dallas, TX 75206 | Oil & Gas Operator | Mar 2021 |
| 9 | Damson Oil Corporation | Houston, TX 77210 | Oil & Gas Operator | Mar 2005 |
| 10 | Daniels Earlene Inc | Follett, TX 79034-9736 | Oil & Gas Operator | Mar 2015 |
| 11 | Darnell Bobby J | Oklahoma City, OK 73112-8884 | Oil & Gas Operator | Sep 2025 |
| 12 | Darrah Oil Company, LLC | Wichita, KS 67201 | Oil & Gas Operator | Dec 2025 |
| 13 | Davis Operating Company | Elysian Field, TX 75642 | Oil & Gas Operator | Dec 2025 |
| 14 | Dawson Resources Inc | Franktown, CO 80116 | Oil & Gas Operator | Mar 2015 |
| 15 | Dawson-Markwell Exploration Co. | Oklahoma City, OK 73101 | Oil & Gas Operator | Sep 2025 |
| 16 | DCP Operating Co LP | Houston, TX 77042 | Oil & Gas Operator | Aug 2025 |
| 17 | Decalta International Corp | Denver, CO 80202 | Oil & Gas Operator | Mar 2015 |
| 18 | Dedica Energy Corporation | Mattoon, IL 61938 | Oil & Gas Operator | Mar 2008 |
| 19 | Dehart Company (The) | Ardmore, OK 73402 | Oil & Gas Operator | Sep 2025 |
| 20 | Deka Exploration Inc | Oklahoma City, OK 73113-0057 | Oil & Gas Operator | Nov 2019 |
| 21 | Denveramerican Petro LLC | | Oil & Gas Operator | May 2006 |
| 22 | Dette Oil Corporation | Oklahoma City, OK 73162-6249 | Oil & Gas Operator | Oct 2015 |
| 23 | Devon Energy Corp (Nevada) | Oklahoma City, OK 73102 | Oil & Gas Operator | Feb 2017 |
| 24 | Devon Energy Operating Corp | Oklahoma City, OK 73102 | Oil & Gas Operator | Apr 2013 |
| 25 | Devon Energy Production Company, L.P. | Oklahoma City, OK 73102 | Oil & Gas Operator | Dec 2025 |
| 26 | Devon Louisiana Corporation | Houston, TX 77002 | Oil & Gas Operator | Oct 2019 |
| 27 | Devon SFS Operating Inc | Oklahoma City, OK 73102 | Oil & Gas Operator | Mar 2008 |
| 28 | Dexxon Inc | Kiefer, OK 74041 | Oil & Gas Operator | Aug 2025 |
| 29 | Dillingham Ranch LC | Tulsa, OK 74152 | Oil & Gas Operator | May 2013 |
| 30 | Diversified Production LLC | Keithville, LA 71047 | Oil & Gas Operator | Dec 2025 |
| 31 | DLB Energy Corporation | Oklahoma City, OK 73118-1401 | Oil & Gas Operator | Dec 2014 |
| 32 | DLB Oil & Gas, Inc. | Big Lake, TX 76932 | Oil & Gas Operator | Dec 2025 |
| 33 | DMS Oil Company | Houston, TX 77042 | Oil & Gas Operator | Sep 2025 |
| 34 | Dominion Exploration & Production Inc | Houston, TX 77060 | Oil & Gas Operator | Apr 2015 |
| 35 | Dominion Ok TX E & P Inc | Oklahoma City, OK 73134 | Oil & Gas Operator | Nov 2018 |
| 36 | Dorchester Resources LP | Oklahoma City, OK 73154-8879 | Oil & Gas Operator | Aug 2021 |
| 37 | Double "C" Energy | Coweta, OK 74429 | Oil & Gas Operator | Mar 2015 |
| 38 | Drake Exploration Inc | Tulsa, OK 74105-4250 | Oil & Gas Operator | Sep 2025 |
| 39 | Duggan Stephen F | Boston, MA 2131 | Oil & Gas Operator | Jun 2010 |
| 40 | Duncan Jr J Walter | Oklahoma City, OK 73102 | Oil & Gas Operator | Dec 2016 |
| 41 | Dyco Petroleum Corporation | Tulsa, OK 74103 | Oil & Gas Operator | Mar 2015 |