| 201 | Cross Timbers Operating Company | Fort Worth, TX 76102 | Oil & Gas Operator | Jun 2025 |
| 202 | Crown Energy Company | Oklahoma City, OK 73106 | Oil & Gas Operator | Sep 2025 |
| 203 | Crusader Energy Corporation | Oklahoma City, OK 73102 | Oil & Gas Operator | Sep 2011 |
| 204 | Crusader Energy Group Inc. | Austin, TX 78746 | Oil & Gas Operator | Mar 2015 |
| 205 | Crystal Energy Inc | Oklahoma City, OK 73116 | Oil & Gas Operator | Feb 2019 |
| 206 | D & D Pipe & Equipment Inc | Kingfisher, OK 73750 | Oil & Gas Operator | Mar 2005 |
| 207 | D & J Oil Company | Kermit, TX 79745 | Oil & Gas Operator | Dec 2025 |
| 208 | D C Energy, Inc. | Oklahoma City, OK 73134 | Oil & Gas Operator | Apr 2020 |
| 209 | D-Mil Production Inc | Argyle, TX 76226 | Oil & Gas Operator | Dec 2025 |
| 210 | D.J.F. Services, Inc. | Holdenville, OK 74848 | Oil & Gas Operator | Dec 2025 |
| 211 | Dabb Energy Company | Fort Worth, TX 76132 | Oil & Gas Operator | Aug 2020 |
| 212 | Dalcor Energy LLC | Duncan, OK 73534 | Oil & Gas Operator | Sep 2025 |
| 213 | Dalen Resources Oil & Gas Co | Dallas, TX 75206 | Oil & Gas Operator | Jun 2010 |
| 214 | Dallas Production, Inc. | Dallas, TX 75206 | Oil & Gas Operator | Mar 2021 |
| 215 | Damson Oil Corporation | Houston, TX 77210 | Oil & Gas Operator | Mar 2005 |
| 216 | Daniel Resource Dev Inc | Tomball, TX 77375-8919 | Oil & Gas Operator | Oct 2009 |
| 217 | Davco Productions Inc | Springer, OK 73458-8191 | Oil & Gas Operator | Jun 2021 |
| 218 | Davis, William H. | Tulsa, OK 74103 | Oil & Gas Operator | Apr 2014 |
| 219 | Daylight Petroleum LLC | Houston, TX 77052 | Oil & Gas Operator | Dec 2025 |
| 220 | DCP Operating Co LP | Houston, TX 77042 | Oil & Gas Operator | Oct 2025 |
| 221 | Dead Horse Oil & Gas LLC | Skiatook, OK 74070-9343 | Oil & Gas Operator | Jun 2015 |
| 222 | Deka Exploration Inc | Oklahoma City, OK 73113-0057 | Oil & Gas Operator | Nov 2019 |
| 223 | Dernick Resources Inc | Dallas, TX 75204 | Oil & Gas Operator | Jan 2002 |
| 224 | Dette Oil Corporation | Oklahoma City, OK 73162-6249 | Oil & Gas Operator | Oct 2015 |
| 225 | Devon Energy Corp (Nevada) | Oklahoma City, OK 73102 | Oil & Gas Operator | Feb 2017 |
| 226 | Devon Energy Production Company, L.P. | Oklahoma City, OK 73102 | Oil & Gas Operator | Dec 2025 |
| 227 | Devon Louisiana Corporation | Houston, TX 77002 | Oil & Gas Operator | Oct 2019 |
| 228 | Diamond A Inc. | Tulsa, OK 74137 | Oil & Gas Operator | Jun 2001 |
| 229 | Diamond Energy Operating Company | Tulsa, OK 74137 | Oil & Gas Operator | Mar 2005 |
| 230 | Dickerson Dennis | Velma, OK 73491 | Oil Operator | Sep 2025 |
| 231 | DLB Energy Corporation | Oklahoma City, OK 73118-1401 | Oil & Gas Operator | Dec 2014 |
| 232 | DLB Oil & Gas, Inc. | Big Lake, TX 76932 | Oil & Gas Operator | Dec 2025 |
| 233 | DLKB Operating LLC | Eufaula, OK 74432 | Gas Operator | Sep 2025 |
| 234 | DMS Oil Company | Houston, TX 77042 | Oil & Gas Operator | Sep 2025 |
| 235 | Dolphin Energy LLC | Lake Worth, FL 33467 | Oil & Gas Operator | Jun 2025 |
| 236 | Dominion Exp Midcontinent Inc | Oklahoma City, OK 73134-2616 | Oil & Gas Operator | Oct 2024 |
| 237 | Dominion Ok TX E & P Inc | Oklahoma City, OK 73134 | Oil & Gas Operator | Nov 2018 |
| 238 | Dorchester Resources LP | Oklahoma City, OK 73154-8879 | Oil & Gas Operator | Aug 2021 |
| 239 | Draco Production Company | Tulsa, OK 74133 | Oil & Gas Operator | Jul 2012 |
| 240 | Drummond, F F | | Oil Operator | Sep 2025 |
| 241 | Duncan Oil Properties, Inc. | Oklahoma City, OK 73102 | Oil & Gas Operator | Dec 2025 |
| 242 | Durango Energy Inc | Chickasha, OK 73023 | Oil Operator | Dec 1999 |
| 243 | Durango Exploration LLC | Oklahoma City, OK 73120-5309 | Oil & Gas Operator | Oct 2025 |
| 244 | Dyco Petroleum Corporation | Tulsa, OK 74103 | Oil & Gas Operator | Mar 2015 |
| 245 | Eagle Exploration Production LLC | Tulsa, OK 74103 | Oil & Gas Operator | Oct 2025 |
| 246 | Eagle Oil & Gas Co. | Dallas, TX 75225 | Oil & Gas Operator | Dec 2025 |
| 247 | Eagle Rock Mid-Continent Operating LLC | Tulsa, OK 74103-3703 | Oil & Gas Operator | Sep 2025 |
| 248 | Earlsboro Energies Corporation | Oklahoma City, OK 73116-3605 | Oil & Gas Operator | Oct 2025 |
| 249 | Echo E & P LLC | Oklahoma City, OK 73102-6439 | Oil & Gas Operator | Oct 2025 |
| 250 | Eckard Operating, LLC | Oklahoma City, OK 73142 | Oil & Gas Operator | Sep 2025 |
| 251 | Edinger Engineering, Inc. | Oklahoma City, OK 73102 | Oil & Gas Operator | Oct 2025 |
| 252 | Eec Inc | Norman, OK 73069-6344 | Oil & Gas Operator | Oct 2025 |
| 253 | El Paso Natural Gas Company | El Paso, TX 79978 | Oil & Gas Operator | Apr 2013 |
| 254 | El Paso Production Company | Houston, TX 77002 | Oil & Gas Operator | Mar 2016 |
| 255 | Elder & Vaughn Inc | Oklahoma City, OK 73154-0938 | Oil & Gas Operator | Mar 2008 |
| 256 | Elite Tank Trucks, Inc | | Oil & Gas Operator | Oct 2025 |
| 257 | Emjo Operations Inc | Marlow, OK 73055-8803 | Oil & Gas Operator | Oct 2025 |
| 258 | Enable Gas Transmission LLC | Houston, TX 77002 | Oil & Gas Operator | Sep 2022 |
| 259 | Enable Oklahoma Intrastate Transmission LLC | Houston, TX 77002 | Oil & Gas Operator | Jul 2022 |
| 260 | Encana Energy Resources Inc | Denver, CO 80202-2828 | Oil & Gas Operator | Feb 2024 |
| 261 | Encore Operating LP | Plano, TX 75024 | Oil & Gas Operator | Oct 2025 |
| 262 | Energyquest II, LLC | The Woodlands, TX 77381 | Oil & Gas Operator | Oct 2025 |
| 263 | Enernet Inc | Oklahoma City, OK 73102-8004 | Oil & Gas Operator | Nov 2014 |
| 264 | Enerquest Oil & Gas LLC | Oklahoma City, OK 73114 | Oil & Gas Operator | Oct 2025 |
| 265 | Enervest Operating LLC | Houston, TX 77002 | Oil & Gas Operator | Dec 2025 |
| 266 | Enserch Exploration Inc | Dallas, TX 75206 | Oil & Gas Operator | Apr 2015 |
| 267 | Entex Petroleum Inc | Oklahoma City, OK 73113 | Oil & Gas Operator | Nov 1997 |
| 268 | EOG (Oklahoma) Inc. | Oklahoma City, OK 73112 | Oil & Gas Operator | Oct 2016 |
| 269 | EOG Resources Inc | Midland, TX 79702 | Oil & Gas Operator | Dec 2025 |
| 270 | Eott Energy Corporation | Oklahoma City, OK 73118 | Oil & Gas Operator | Dec 1995 |
| 271 | EP Energy E&P Company, LP | Houston, TX 77210 | Oil & Gas Operator | Jan 2023 |
| 272 | EP Operating LP | Dallas, TX 75201 | Oil & Gas Operator | Mar 2015 |
| 273 | Esco Exploration, Inc | Dallas, TX 75201 | Oil & Gas Operator | Mar 2015 |
| 274 | Esis Inc | | Oil & Gas Operator | Feb 2017 |
| 275 | Eubank Operating Company | Cushing, OK 74023 | Oil & Gas Operator | Aug 2024 |
| 276 | Evolution Energy LLC | Oklahoma City, OK 73116 | Oil & Gas Operator | Oct 2025 |
| 277 | Exco Resources Inc | Dallas, TX 75251 | Oil & Gas Operator | Sep 2025 |
| 278 | Exok Inc | Oklahoma City, OK 73116 | Oil & Gas Operator | Oct 2025 |
| 279 | Exxon Mobil Corporation | Spring, TX 77389 | Oil & Gas Operator | Dec 2025 |
| 280 | Exxonmobil Oil Corp | Houston, TX 77210 | Oil & Gas Operator | Aug 2025 |
| 281 | Fahrenheit Petroleum Co Inc | | Oil & Gas Operator | Mar 2015 |
| 282 | Fairway Resources Operating III LLC | Houston, TX 77002-2728 | Oil & Gas Operator | Oct 2025 |
| 283 | Far West Development, LLC | Oklahoma City, OK 73118 | Oil & Gas Operator | Dec 2025 |
| 284 | Faulconer, Vernon E., Inc. | Tyler, TX 75711 | Oil & Gas Operator | Oct 2025 |
| 285 | FBF Energy LLC | Tulsa, OK 74120 | Oil & Gas Operator | Oct 2025 |
| 286 | FDL Operating, LLC | Judson, TX 75660 | Oil & Gas Operator | Dec 2025 |
| 287 | Femco Services Inc | Lindsay, OK 73052-0632 | Oil & Gas Operator | Nov 2006 |
| 288 | Femco SWD Inc | Enid, OK 73702-3907 | Oil Operator | Mar 2014 |
| 289 | Ferguson Oil Company Inc | | Oil & Gas Operator | Apr 1994 |
| 290 | Flint Douglas J | Mounds, OK 74047-5415 | Oil & Gas Operator | Sep 2015 |
| 291 | Flint J A & Associates | Holdenville, OK 74848 | Oil & Gas Operator | Sep 2009 |
| 292 | Flow Production Company | Midland, TX 79708 | Oil & Gas Operator | Mar 2005 |
| 293 | Fluid Disposal Services LLC | Chickasha, OK 73018-9684 | Oil Operator | Aug 2015 |
| 294 | Focus Energy, Inc. | Oklahoma City, OK 73154 | Oil & Gas Operator | Nov 2019 |
| 295 | Ford Energy Corporation | Chickasha, OK 73018 | Oil & Gas Operator | Sep 2025 |
| 296 | Foreman Enterprises Inc | Edmond, OK 73003 | Oil & Gas Operator | Sep 2025 |
| 297 | Formentera Operations LLC | Austin, TX 78701 | Oil & Gas Operator | Dec 2025 |
| 298 | Four Seas Exploration LLC | Oklahoma City, OK 73101-1557 | Oil & Gas Operator | Dec 2019 |
| 299 | Four Star Oil & Gas Company | Houston, TX 77252 | Oil & Gas Operator | Sep 2025 |
| 300 | Fpco Oil & Gas Co. | New Orleans, LA 70160 | Oil & Gas Operator | Jun 2025 |