| 1 | D C Energy, Inc. | Oklahoma City, OK 73134 | Oil & Gas Operator | Apr 2020 |
| 2 | Dab Limited | Oklahoma City, OK 73116-9082 | Oil & Gas Operator | Aug 2013 |
| 3 | Dalen Resources Oil & Gas Co. | Dallas, TX 75206 | Oil & Gas Operator | Jun 2010 |
| 4 | Damson Oil Corporation | Houston, TX 77210 | Oil & Gas Operator | Mar 2005 |
| 5 | Danick Operating USA Inc | McKinney, TX 75072-9071 | Oil & Gas Operator | Oct 2022 |
| 6 | David E Morgan Inc | Danville, CA 94506-2035 | Oil & Gas Operator | Jul 2025 |
| 7 | Davis & Davis | | Oil & Gas Operator | Dec 2021 |
| 8 | Davis Operating Company | Elysian Field, TX 75642 | Oil & Gas Operator | Oct 2025 |
| 9 | Davis, William H. | Tulsa, OK 74103 | Oil & Gas Operator | Apr 2014 |
| 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 | Dee-Jay Exploration Company | Nichols Hill, OK 73116 | Oil & Gas Operator | Oct 2025 |
| 13 | Delta D Operations Inc | Ardmore, OK 73401-8678 | Oil & Gas Operator | Apr 2014 |
| 14 | Denveramerican Petro LLC | | Oil & Gas Operator | May 2006 |
| 15 | Derrick Resources Inc. | Henryetta, OK 74437-4249 | Oil & Gas Operator | Jun 2025 |
| 16 | Dette Oil Corporation | Oklahoma City, OK 73162-6249 | Oil & Gas Operator | Oct 2015 |
| 17 | Devon Energy Corp (Nevada) | Oklahoma City, OK 73102 | Oil & Gas Operator | Feb 2017 |
| 18 | Devon Energy Production Company LP | Oklahoma City, OK 73102 | Oil & Gas Operator | Oct 2025 |
| 19 | Devon SFS Operating Inc | Oklahoma City, OK 73102 | Oil & Gas Operator | Mar 2008 |
| 20 | Dinsmore C E | Enid, OK 73702 | Oil & Gas Operator | May 2009 |
| 21 | Discovery Operating Inc | Midland, TX 79705 | Oil & Gas Operator | Oct 2025 |
| 22 | Diversified Production LLC | Keithville, LA 71047 | Oil & Gas Operator | Oct 2025 |
| 23 | DLB Energy Corporation | Oklahoma City, OK 73118-1401 | Oil & Gas Operator | Dec 2014 |
| 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 | Dominion Exploration & Production Inc | Houston, TX 77060 | Oil & Gas Operator | Apr 2015 |
| 27 | Dominion Ok TX E & P Inc | Oklahoma City, OK 73134 | Oil & Gas Operator | Nov 2018 |
| 28 | Dorchester Resources LP | Oklahoma City, OK 73154-8879 | Oil & Gas Operator | Aug 2021 |
| 29 | Double "C" Energy | Coweta, OK 74429 | Oil & Gas Operator | Mar 2015 |
| 30 | Douglass Dietz & Daley Inc | Oklahoma City, OK 73154-0125 | Oil & Gas Operator | Aug 2023 |
| 31 | Draco Production Company | Tulsa, OK 74133 | Oil & Gas Operator | Jul 2012 |
| 32 | Dragon Energy LLC | Tulsa, OK 74135-7234 | Oil & Gas Operator | Feb 2015 |
| 33 | DSM Exploration Inc | Oklahoma City, OK 73154 | Oil & Gas Operator | May 1996 |
| 34 | Duncan Jr J Walter | Oklahoma City, OK 73102 | Oil & Gas Operator | Dec 2016 |
| 35 | Durango Exploration LLC | Oklahoma City, OK 73120-5309 | Oil & Gas Operator | Jul 2025 |
| 36 | Dyco Petroleum Corporation | Tulsa, OK 74103 | Oil & Gas Operator | Mar 2015 |