| 201 | Domestic Oil Producers,Inc. | | Oil Operator | Oct 1998 |
| 202 | Dominion Exploration & Production Inc | Houston, TX 77060 | Oil & Gas Operator | Apr 2015 |
| 203 | Dominion Midstream Services, LP | | Oil Operator | Dec 2006 |
| 204 | Dominion Minerals Corporation | Houston, TX 77014 | Oil & Gas Operator | Nov 2009 |
| 205 | Don G. Wiley, Jr. | | Oil Operator | Dec 1979 |
| 206 | Don Townes | | Oil Operator | Sep 2000 |
| 207 | Don W. Holcomb | | Oil Operator | Feb 1996 |
| 208 | Don Webb | | Oil Operator | Mar 1984 |
| 209 | Donald & Danny Dews Production | | Oil Operator | Jan 2024 |
| 210 | Donald J. Zadeck | | Oil & Gas Operator | Feb 1998 |
| 211 | Donald Owens | | Oil & Gas Operator | Dec 2023 |
| 212 | Donn G. Thompson, Et Al | | Oil Operator | Apr 1987 |
| 213 | Donnie R. Morrow | | Oil Operator | Dec 2023 |
| 214 | Donny Joe Barnhill | | Gas Operator | Dec 2023 |
| 215 | Doran & Braddock & Nelson Petr | | Oil Operator | Feb 1982 |
| 216 | Doran And Braddock | | Oil & Gas Operator | Nov 1984 |
| 217 | Dorbert Oil & Gas, Inc. | | Gas Operator | Aug 1988 |
| 218 | Dorcheat Oil & Gas, LLC | | Oil & Gas Operator | Jan 2024 |
| 219 | Dorchester Exploration, Inc. | Dallas, TX 75231 | Oil & Gas Operator | Aug 2001 |
| 220 | Dore-Dyn Production Co., Inc. | | Oil & Gas Operator | Jul 1993 |
| 221 | Dorothy F. Hamlin | | Oil Operator | Dec 1985 |
| 222 | Dorothy Oil Company | | Oil & Gas Operator | Oct 1994 |
| 223 | Dossie Dews | | Oil & Gas Operator | Jan 2024 |
| 224 | Double Eagle Petroleum Corp | Evansville, IN 47725 | Oil & Gas Operator | Apr 2024 |
| 225 | Double J Operating Company, Inc. | San Antonio, TX 78205 | Oil Operator | Jan 2008 |
| 226 | Douglas Edwards | | Oil Operator | Nov 1993 |
| 227 | Dove Drilling, Inc. | Kilgore, TX 75663 | Oil & Gas Operator | Nov 1997 |
| 228 | Dow Intrastate Gas Company | | Oil Operator | Nov 2023 |
| 229 | Dow Mineral & Royalty Co, Inc | | Oil & Gas Operator | Jun 1994 |
| 230 | Doyle Dempsey | | Oil Operator | May 1997 |
| 231 | Dragon Energy Corporation | | Oil & Gas Operator | Nov 2006 |
| 232 | Drake Energy Corporation | | Gas Operator | Dec 2023 |
| 233 | DRD Operating Company | | Oil & Gas Operator | Feb 2014 |
| 234 | Drew Cornell, Inc. | | Oil & Gas Operator | Jul 1992 |
| 235 | Drew Cornell, Inc.-Agent | | Oil & Gas Operator | Sep 1990 |
| 236 | Drew Cornell,Inc.-C.H.Lawrence | | Oil & Gas Operator | Sep 1990 |
| 237 | Drew Cornell,Inc.-R Waterbury | | Oil Operator | Jun 1999 |
| 238 | DRG Energy Inc | Norman, OK 73026-3171 | Oil & Gas Operator | Nov 2023 |
| 239 | Drilling, Operg & Explor, Inc. | | Oil & Gas Operator | Feb 1990 |
| 240 | Drillmar Energy, Inc. | Houston, TX 77079 | Oil & Gas Operator | Nov 2014 |
| 241 | Drillmar Operating Company | Houston, TX 77019 | Oil & Gas Operator | Jun 2013 |
| 242 | Drmas, LLC | | Oil & Gas Operator | Nov 2023 |
| 243 | Drum Energy, L.L.C. | | Gas Operator | Dec 2016 |
| 244 | Dual Energy, Inc. | | Oil & Gas Operator | Oct 2022 |
| 245 | Dubach Gas Company | | Oil Operator | May 2003 |
| 246 | Ducharme Oil, LLC | | Oil & Gas Operator | Nov 2023 |
| 247 | Ducote Oil Co. | | Oil & Gas Operator | Sep 1997 |
| 248 | Duer Wagner & Company | Fort Worth, TX 76102 | Oil & Gas Operator | Dec 1998 |
| 249 | Duke Energy Field Services Inc | | Oil Operator | Mar 2000 |
| 250 | Duke Energy Field Services LLC | | Oil Operator | Dec 2006 |
| 251 | Duncan Energy Company | Denver, CO 80202 | Oil & Gas Operator | Mar 2008 |
| 252 | Duncan Oil Company | Holliday, TX 76366 | Oil Operator | Mar 2008 |
| 253 | Duncan Oil Inc | Denver, CO 80210 | Oil & Gas Operator | Jun 2016 |
| 254 | Dundee Petroleum, Inc. | Buffalo Gap, TX 79508 | Oil & Gas Operator | Aug 2003 |
| 255 | Dune Operating Company | Dallas, TX 75201 | Oil & Gas Operator | Jun 2016 |
| 256 | Dunhill Expl. & Prod., LLC | | Oil & Gas Operator | Nov 2004 |
| 257 | Dunhill Resources, Inc. | | Oil & Gas Operator | Nov 2005 |
| 258 | Dunn Exploration Company, LLC | | Oil & Gas Operator | Jan 2024 |
| 259 | Dupont Oil Company | | Oil Operator | Feb 1998 |
| 260 | Dupree And Dupree | | Oil Operator | Dec 1998 |
| 261 | Dvi | | Oil Operator | Dec 2008 |
| 262 | Dyco Petroleum Corporation | Tulsa, OK 74103 | Oil & Gas Operator | Mar 2015 |
| 263 | Dykes Oil Co. | | Oil Operator | Dec 2001 |
| 264 | Dynaco, Incorporated | | Oil & Gas Operator | Dec 1980 |
| 265 | Dynamic Exploration PTRS, LLC | | Oil & Gas Operator | Jan 2024 |
| 266 | Dynamic Exploration, Inc. | | Oil & Gas Operator | Oct 2003 |
| 267 | Dynamic Offshore Resources, LLC | Houston, TX 77042 | Oil & Gas Operator | Apr 2024 |
| 268 | Dzurik Interests, Inc. | | Oil & Gas Operator | Nov 2023 |