| 301 | Duncan W T | | Oil Operator | Nov 1998 |
| 302 | Duncan Walter | | Oil & Gas Operator | May 2019 |
| 303 | Dundee Oil & Supply Inc | Tulsa, OK 74101 | Oil & Gas Operator | Apr 2001 |
| 304 | Dune Resources Inc | Tulsa, OK 74103 | Oil & Gas Operator | Jan 1993 |
| 305 | Dunigan Operating Company, Inc. | Austin, TX 78755 | Oil & Gas Operator | Mar 2025 |
| 306 | Dunkin Oil And Gas LLC | Wynewood, OK 73098-9196 | Oil Operator | Dec 2024 |
| 307 | Dunlap Drilling & Prod Inc | Glenpool, OK 74033-4206 | Oil & Gas Operator | Nov 2024 |
| 308 | Dunlap Jr E | | Oil & Gas Operator | May 1997 |
| 309 | Dunlap Oil Company | Bristow, OK 74010 | Oil & Gas Operator | Dec 2024 |
| 310 | Dunlap Well Service Inc | Haskell, OK 74436 | Oil & Gas Operator | Sep 1993 |
| 311 | Dunn Energy LLC | Skiatook, OK 74070-4046 | Oil Operator | Sep 2022 |
| 312 | Dunn'S Oil And Gas Lease Management LLC | Ardmore, OK 73401 | Oil & Gas Operator | Dec 2024 |
| 313 | Dunn'S Tank Service Inc | Fox, OK 73435-0232 | Oil Operator | Sep 2014 |
| 314 | Dunne Equities Operating, Inc. | Houston, TX 77057 | Oil & Gas Operator | Aug 2022 |
| 315 | Dunne Equities, Inc. | Wichita, KS 67226 | Oil & Gas Operator | Apr 2014 |
| 316 | Durango Energy Inc | Chickasha, OK 73023 | Oil Operator | Dec 1999 |
| 317 | Durango Exploration LLC | Oklahoma City, OK 73120-5309 | Oil & Gas Operator | Jan 2025 |
| 318 | Durango Resources Corp. | Houston, TX 77043 | Oil & Gas Operator | Mar 2025 |
| 319 | Durossette Bill D | Haskell, OK 74436-1350 | Oil & Gas Operator | Jul 2004 |
| 320 | Durossette Floyd R | Warner, OK 74469-0548 | Oil & Gas Operator | Apr 2011 |
| 321 | Durossette Jr Jess | Haskell, OK 74436 | Oil Operator | Mar 2007 |
| 322 | DW Oil & Gas LLC | Okmulgee, OK 74447 | Oil & Gas Operator | Dec 2024 |
| 323 | DWJS Inc | Oklahoma City, OK 73159 | Oil & Gas Operator | Sep 2024 |
| 324 | Dyco Petroleum Corporation | Tulsa, OK 74103 | Oil & Gas Operator | Mar 2015 |
| 325 | Dyer Dale E Dba The Loving Company | Tulsa, OK 74107 | Oil & Gas Operator | Dec 2024 |
| 326 | Dyne Exploration Company | Plano, TX 75093-6512 | Oil & Gas Operator | Apr 2020 |
| 327 | Dyno Energy LLC | Oklahoma City, OK 73118 | Oil & Gas Operator | Dec 2024 |