| 201 | Double R Oil Co. | Charlotte, TX 78011 | Oil & Gas Operator | May 2010 |
| 202 | Double Ten Petro | | Oil Operator | Jul 1994 |
| 203 | Doudna, Mark A. | Osawatomie, KS 66064 | Oil Operator | Nov 2009 |
| 204 | Doug'S Pumping Service | | Oil Operator | Sep 2025 |
| 205 | Dover Atwood Corp. | Massillon, OH 44646 | Oil & Gas Operator | Dec 2024 |
| 206 | Downing-Nelson Oil Co Inc | Hays, KS 67601 | Oil & Gas Operator | Sep 2025 |
| 207 | DR Well Operator | | Oil Operator | Jan 1990 |
| 208 | Drake Exploration LLC | Arkansas City, KS 67005 | Oil & Gas Operator | Nov 2025 |
| 209 | Dreiling Exploration LLC | Victoria, KS 67671 | Oil Operator | Mar 2018 |
| 210 | Dreiling Limited | | Oil Operator | Jun 1984 |
| 211 | Dreiling Oil Inc | Hays, KS 67601 | Oil Operator | Jun 2018 |
| 212 | Dreiling Resourc | | Oil Operator | Oct 1996 |
| 213 | Dreiling Resources Inc. | Victoria, KS 67671 | Oil Operator | Sep 1997 |
| 214 | Dreyer Oil | | Oil Operator | Dec 2019 |
| 215 | Dreyer Oil - Lel | | Oil Operator | Nov 1993 |
| 216 | Driftwood Oil Co. | Russell, KS 67665 | Oil Operator | Jan 1988 |
| 217 | Drilex Oil & Gas | | Oil Operator | Apr 1987 |
| 218 | Driller'S & Prod | | Oil & Gas Operator | Oct 1994 |
| 219 | Drillers & Producers, Inc. | Newton, KS 67114 | Oil Operator | Dec 2019 |
| 220 | Driscoll Jerry J | | Oil Operator | Apr 1994 |
| 221 | Driscoll Lease O | | Oil Operator | Jul 1988 |
| 222 | Driscoll Lease Operations, Inc. | Russell, KS 67665 | Oil Operator | Dec 1998 |
| 223 | Driscoll, Jerry J Oil Investment Inc | Russell, KS 67665 | Oil Operator | Sep 2025 |
| 224 | DRL Operating In | | Oil Operator | Sep 1986 |
| 225 | Drop Tine Exploration, LLC | Medicine Lodge, KS 67104 | Oil & Gas Operator | Dec 2019 |
| 226 | Du Pont Oil Comp | | Oil Operator | May 1984 |
| 227 | Duane Exploration Limited | Andover, KS 67002 | Oil Operator | Jul 1996 |
| 228 | Dubois, Allen | Whitewater, KS 67154 | Oil Operator | May 2000 |
| 229 | Dudrey Carl | | Oil & Gas Operator | Feb 1993 |
| 230 | Duer Wagoner Com | | Gas Operator | Sep 1988 |
| 231 | Duke Drilling Co | Wichita, KS 67202 | Oil & Gas Operator | Feb 2006 |
| 232 | Duke Oil & Gas Company, LLC | Wellsville, KS 66092 | Oil Operator | Sep 2025 |
| 233 | Duke Oil LLC | Garnett, KS 66032 | Oil Operator | Sep 2025 |
| 234 | Duke, Hanes Partnership | San Clemente, CA 92672 | Gas Operator | Oct 2004 |
| 235 | Dunbar & Son Oil | | Oil & Gas Operator | Oct 1988 |
| 236 | Duncan Energy Company | Denver, CO 80202 | Oil & Gas Operator | Mar 2008 |
| 237 | Duncan Oil Properties, Inc. | Oklahoma City, OK 73102 | Oil & Gas Operator | Feb 2026 |
| 238 | Dunham'S Oil, LLC | Eureka, KS 67045 | Oil Operator | Aug 2025 |
| 239 | Dunne Equities I | | Oil & Gas Operator | Dec 1995 |
| 240 | Dunne Equities Operating, Inc. | Houston, TX 77057 | Oil & Gas Operator | Aug 2022 |
| 241 | Dunne Equities, Inc. | Wichita, KS 67226 | Oil & Gas Operator | Apr 2014 |
| 242 | Dunne Investments Operating, Inc. | Wichita, KS 67226 | Oil Operator | Mar 2002 |
| 243 | Dunne Oil Co. | Wichita, KS 67202 | Oil Operator | Apr 1999 |
| 244 | Dunne-Gardner Pe | | Oil & Gas Operator | Nov 1992 |
| 245 | Dunne-Gardner Petroleum, Inc. | Wichita, KS 67202 | Gas Operator | Jun 2022 |
| 246 | Dunsmoor, David E. | Grand Junction, CO 81504 | Oil Operator | Jul 1998 |
| 247 | Durbin, Ronald R. | Moline, KS 67353 | Oil Operator | Dec 1988 |
| 248 | Dustin Enterprise | Olathe, KS 66062 | Oil Operator | Feb 1998 |
| 249 | Dutton Bill J Oi | | Oil & Gas Operator | Oct 1992 |
| 250 | Dwarf Oil Company | | Oil & Gas Operator | Mar 2025 |
| 251 | Dyco Petroleum Corporation | Tulsa, OK 74103 | Oil & Gas Operator | Mar 2015 |
| 252 | Dyer, Charles Wilbur | Longton, KS 67352 | Oil Operator | Jul 2025 |