| 1 | D & B Operating, Inc. | Midland, TX 79701 | Oil & Gas Operator | Dec 2003 |
| 2 | D & D Pipe & Equipment Inc | Kingfisher, OK 73750 | Oil & Gas Operator | Mar 2005 |
| 3 | D & S Operating | Texhoma, OK 73949 | Oil & Gas Operator | May 2001 |
| 4 | D C Energy, Inc. | Oklahoma City, OK 73134 | Oil & Gas Operator | Apr 2020 |
| 5 | D-Mil Production Inc | Argyle, TX 76226 | Oil & Gas Operator | Oct 2025 |
| 6 | Dabb Energy Company | Fort Worth, TX 76132 | Oil & Gas Operator | Aug 2020 |
| 7 | Dale George | Elmore City, OK 73433 | Oil & Gas Operator | Aug 2022 |
| 8 | Dalen Resources Oil & Gas Co. | Dallas, TX 75206 | Oil & Gas Operator | Jun 2010 |
| 9 | Dallas Production, Inc. | Dallas, TX 75206 | Oil & Gas Operator | Mar 2021 |
| 10 | Damson Oil Corporation | Houston, TX 77210 | Oil & Gas Operator | Mar 2005 |
| 11 | Danco Enterprises Inc | Ada, OK 74820 | Oil Operator | Apr 2008 |
| 12 | Darwin Allen Dba Wil-Mar Operations | Duncan, OK 73534-1566 | Oil & Gas Operator | Oct 2016 |
| 13 | Dash Operating LLC | Oklahoma City, OK 73118-5031 | Oil & Gas Operator | Jun 2025 |
| 14 | Daube Company The | Ardmore, OK 73401 | Oil & Gas Operator | Jul 2025 |
| 15 | Daube Exploration Company | Ardmore, OK 73402 | Oil & Gas Operator | Nov 2020 |
| 16 | Davis Henry | Tulsa, OK 74135-3567 | Oil & Gas Operator | Dec 1994 |
| 17 | Davis Operating Company | Elysian Field, TX 75642 | Oil & Gas Operator | Oct 2025 |
| 18 | Davis William W | | Oil Operator | Jun 2024 |
| 19 | Davis, William H. | Tulsa, OK 74103 | Oil & Gas Operator | Apr 2014 |
| 20 | Daylight Petroleum LLC | Houston, TX 77052 | Oil & Gas Operator | Oct 2025 |
| 21 | DCP Operating Co LP | Houston, TX 77042 | Oil & Gas Operator | May 2025 |
| 22 | Dean'S Well Servicing Inc | Ratliff City, OK 73481 | Oil & Gas Operator | Jun 2025 |
| 23 | Dearing, Inc. | Kilgore, TX 75663 | Oil & Gas Operator | Mar 2021 |
| 24 | Deaton, Gary L. Corporation | Oklahoma City, OK 73105 | Oil & Gas Operator | Mar 2015 |
| 25 | Deck Oil Company | Tulsa, OK 74101 | Oil & Gas Operator | Jun 2020 |
| 26 | Dehart Company (The) | Ardmore, OK 73402 | Oil & Gas Operator | Jul 2025 |
| 27 | Deka Exploration Inc | Oklahoma City, OK 73113-0057 | Oil & Gas Operator | Nov 2019 |
| 28 | Delta D Operations | Wilson, OK 73463 | Oil & Gas Operator | Jul 2014 |
| 29 | Delta D Operations Inc | Ardmore, OK 73401-8678 | Oil & Gas Operator | Apr 2014 |
| 30 | Deminex U.S. Oil Company | | Oil & Gas Operator | Jan 1998 |
| 31 | Derae Oil Company | Seminole, OK 74868-2617 | Oil & Gas Operator | Feb 1997 |
| 32 | Devon Energy Corp (Nevada) | Oklahoma City, OK 73102 | Oil & Gas Operator | Feb 2017 |
| 33 | Diane Oil Company | Oklahoma City, OK 73146 | Oil & Gas Operator | Jul 2025 |
| 34 | Dickerson Oil | Ada, OK 74820 | Oil Operator | Jan 2025 |
| 35 | Dinsmore C E | Enid, OK 73702 | Oil & Gas Operator | May 2009 |
| 36 | Dixie Oil Company Inc | Moore, OK 73153 | Oil & Gas Operator | Nov 1994 |
| 37 | Dixie Petroleum Inc | Cashion, OK 73016 | Oil & Gas Operator | May 2001 |
| 38 | DLB Energy Corporation | Oklahoma City, OK 73118-1401 | Oil & Gas Operator | Dec 2014 |
| 39 | Dominion Ok TX E & P Inc | Oklahoma City, OK 73134 | Oil & Gas Operator | Nov 2018 |
| 40 | Douglass Dietz & Daley Inc | Oklahoma City, OK 73154-0125 | Oil & Gas Operator | Aug 2023 |
| 41 | Downhole Oil & Gas Tech LLC | Countyline, OK 73152-0027 | Oil Operator | Oct 2009 |
| 42 | Draw Oil & Gas Inc | | Oil & Gas Operator | Jun 1995 |
| 43 | Duncan Oil & Gas Inc | Norman, OK 73072 | Oil & Gas Operator | Sep 2020 |
| 44 | Duncan Oil Properties, Inc. | Oklahoma City, OK 73102 | Oil & Gas Operator | Oct 2025 |
| 45 | Dundee Oil & Supply Inc | Tulsa, OK 74101 | Oil & Gas Operator | Apr 2001 |
| 46 | Dunkin Oil And Gas LLC | Wynewood, OK 73098-9196 | Oil Operator | May 2025 |
| 47 | Dunn'S Oil And Gas Lease Management LLC | Ardmore, OK 73401 | Oil & Gas Operator | Jun 2025 |
| 48 | DWJS Inc | Oklahoma City, OK 73159 | Oil & Gas Operator | Sep 2024 |
| 49 | Dyco Petroleum Corporation | Tulsa, OK 74103 | Oil & Gas Operator | Mar 2015 |
| 50 | Dyno Energy LLC | Oklahoma City, OK 73118 | Oil & Gas Operator | Jun 2025 |