| 201 | Creslenn Oil Co | | Oil & Gas Operator | Nov 1998 |
| 202 | Crest Resources Inc | Tulsa, OK 74103 | Oil & Gas Operator | Feb 2026 |
| 203 | Cross Timbers Operating Company | Fort Worth, TX 76102 | Oil & Gas Operator | Sep 2025 |
| 204 | Crusader Energy Corporation | Oklahoma City, OK 73102 | Oil & Gas Operator | Sep 2011 |
| 205 | Crusader Energy Group Inc. | Austin, TX 78746 | Oil & Gas Operator | Mar 2015 |
| 206 | Crusader Energy Group LLC | Oklahoma City, OK 73142 | Oil & Gas Operator | Mar 2015 |
| 207 | Crusader Energy II LLC | Oklahoma City, OK 73102 | Oil & Gas Operator | Mar 2015 |
| 208 | Cudd Operating Corp | Oklahoma City, OK 73118 | Oil & Gas Operator | Apr 2020 |
| 209 | Curzon Operating Company LTD | Oklahoma City, OK 73118-4821 | Oil & Gas Operator | Nov 2025 |
| 210 | D & B Operating, Inc. | Midland, TX 79701 | Oil & Gas Operator | Dec 2003 |
| 211 | D & D Pipe & Equipment Inc | Kingfisher, OK 73750 | Oil & Gas Operator | Mar 2005 |
| 212 | D & J Oil Company | Kermit, TX 79745 | Oil & Gas Operator | Feb 2026 |
| 213 | D & T Swabbing & Well Serv Inc | Hennessey, OK 73742-0124 | Oil & Gas Operator | Nov 2025 |
| 214 | D C Energy, Inc. | Oklahoma City, OK 73134 | Oil & Gas Operator | Apr 2020 |
| 215 | Dakota Oil Company | Hebbronville, TX 78361 | Oil & Gas Operator | Feb 2026 |
| 216 | Dalen Resources Oil & Gas Co | Dallas, TX 75206 | Oil & Gas Operator | Jun 2010 |
| 217 | Damson Oil Corporation | Houston, TX 77210 | Oil & Gas Operator | Mar 2005 |
| 218 | Daube Company The | Ardmore, OK 73401 | Oil & Gas Operator | Nov 2025 |
| 219 | Davis & Davis | | Oil & Gas Operator | Dec 2021 |
| 220 | Davis Operating Company | Elysian Field, TX 75642 | Oil & Gas Operator | Feb 2026 |
| 221 | Dawson Resources Inc | Franktown, CO 80116 | Oil & Gas Operator | Mar 2015 |
| 222 | DCP Operating Co LP | Houston, TX 77042 | Oil & Gas Operator | Nov 2025 |
| 223 | Delong Ralph J | Sapulpa, OK 74066 | Oil & Gas Operator | Nov 2005 |
| 224 | Deminex U S Oil Company | | Oil & Gas Operator | Jan 1998 |
| 225 | Denveramerican Petro LLC | | Oil & Gas Operator | May 2006 |
| 226 | Devon Energy Corp (Nevada) | Oklahoma City, OK 73102 | Oil & Gas Operator | Feb 2017 |
| 227 | Devon Energy Operating Corp | Oklahoma City, OK 73102 | Oil & Gas Operator | Apr 2013 |
| 228 | Devon Energy Production Company, L.P. | Oklahoma City, OK 73102 | Oil & Gas Operator | Feb 2026 |
| 229 | Devon Louisiana Corporation | Houston, TX 77002 | Oil & Gas Operator | Oct 2019 |
| 230 | Devon Resources Corporation | Jenks, OK 74037-3525 | Oil & Gas Operator | Nov 2025 |
| 231 | Diamond A Inc. | Tulsa, OK 74137 | Oil & Gas Operator | Jun 2001 |
| 232 | Diamond B Company Inc | Tulsa, OK 74170 | Oil & Gas Operator | Dec 2010 |
| 233 | Diamond Energy Operating Company | Tulsa, OK 74137 | Oil & Gas Operator | Mar 2005 |
| 234 | Diamond Production Company LLC | Irving, TX 75016-7853 | Oil & Gas Operator | Nov 2025 |
| 235 | Dinsmore C E | Enid, OK 73702 | Oil & Gas Operator | May 2009 |
| 236 | Diversified Production LLC | Keithville, LA 71047 | Oil & Gas Operator | Feb 2026 |
| 237 | Dixie Petroleum Inc | Cashion, OK 73016 | Oil & Gas Operator | May 2001 |
| 238 | DKT Energy LLC | Edmond, OK 73083-6844 | Oil & Gas Operator | Sep 2014 |
| 239 | DLB Energy Corporation | Oklahoma City, OK 73118-1401 | Oil & Gas Operator | Dec 2014 |
| 240 | DLB Oil & Gas, Inc. | Big Lake, TX 76932 | Oil & Gas Operator | Feb 2026 |
| 241 | DMS Oil Company | Houston, TX 77042 | Oil & Gas Operator | Dec 2025 |
| 242 | Doco Development Corporation | Norman, OK 73072 | Oil & Gas Operator | Dec 2025 |
| 243 | Dominion Exploration & Production Inc | Houston, TX 77060 | Oil & Gas Operator | Apr 2015 |
| 244 | Dominion Ok TX E & P Inc | Oklahoma City, OK 73134 | Oil & Gas Operator | Nov 2018 |
| 245 | Donaldson Richard E | Bartlesville, OK 74005-0032 | Oil & Gas Operator | Nov 2005 |
| 246 | Dorchester Resources LP | Oklahoma City, OK 73154-8879 | Oil & Gas Operator | Aug 2021 |
| 247 | Double H Petroleum Corporation | Tulsa, OK 74136-5414 | Oil & Gas Operator | May 2006 |
| 248 | Draco Production Company | Tulsa, OK 74133 | Oil & Gas Operator | Jul 2012 |
| 249 | Duncan Oil Properties, Inc. | Oklahoma City, OK 73102 | Oil & Gas Operator | Feb 2026 |
| 250 | Dyco Petroleum Corporation | Tulsa, OK 74103 | Oil & Gas Operator | Mar 2015 |
| 251 | Ea Petroleum Inc | Norman, OK 73072-4147 | Oil & Gas Operator | May 2006 |
| 252 | Eagle Exploration Production LLC | Tulsa, OK 74103 | Oil & Gas Operator | Dec 2025 |
| 253 | Eagle Oil & Gas Co. | Dallas, TX 75225 | Oil & Gas Operator | Feb 2026 |
| 254 | Eagle Rock Mid-Continent Operating LLC | Tulsa, OK 74103-3703 | Oil & Gas Operator | Nov 2025 |
| 255 | Earlsboro Energies Corporation | Oklahoma City, OK 73116-3605 | Oil & Gas Operator | Nov 2025 |
| 256 | Edinger Engineering, Inc. | Oklahoma City, OK 73102 | Oil & Gas Operator | Dec 2025 |
| 257 | Edwards & Leach Oil Company | Oklahoma City, OK 73114 | Oil & Gas Operator | Mar 2005 |
| 258 | Eec Inc | Norman, OK 73072 | Oil & Gas Operator | Dec 2025 |
| 259 | Egolf Operating Company | Oklahoma City, OK 73114-7899 | Oil & Gas Operator | Apr 1998 |
| 260 | Eight Round Corporation | Seminole, OK 74818-1482 | Oil & Gas Operator | Jul 2012 |
| 261 | El Paso Production Company | Houston, TX 77002 | Oil & Gas Operator | Mar 2016 |
| 262 | Eland Energy Inc | Dallas, TX 75248 | Oil & Gas Operator | Dec 2025 |
| 263 | Elite Resources Inc | Cleveland, OK 74020 | Oil & Gas Operator | Dec 2025 |
| 264 | Elite Tank Trucks, Inc | | Oil & Gas Operator | Nov 2025 |
| 265 | Emc Exploration Company Inc | Oklahoma City, OK 73103-3775 | Oil & Gas Operator | Jul 2007 |
| 266 | Encino Operating, LLC | Houston, TX 77057 | Oil & Gas Operator | Feb 2026 |
| 267 | Encore Operating LP | Plano, TX 75024 | Oil & Gas Operator | Dec 2025 |
| 268 | Endeavor Natural Gas, LLC | Houston, TX 77002 | Oil & Gas Operator | Feb 2015 |
| 269 | Energex Inc. | Abilene, TX 79604 | Oil & Gas Operator | Feb 2026 |
| 270 | Energy Development Corporation | Houston, TX 77067 | Oil & Gas Operator | Dec 2024 |
| 271 | Energy Production Services LLC | Oklahoma City, OK 73162-4736 | Oil & Gas Operator | Apr 2020 |
| 272 | Enernet Inc | Oklahoma City, OK 73102-8004 | Oil & Gas Operator | Nov 2014 |
| 273 | Enerquest Oil & Gas LLC | Oklahoma City, OK 73114 | Oil & Gas Operator | Nov 2025 |
| 274 | Enervest Operating LLC | Houston, TX 77002 | Oil & Gas Operator | Feb 2026 |
| 275 | Ennex Inc | | Oil & Gas Operator | Oct 1993 |
| 276 | Enserch Exploration Inc | Dallas, TX 75206 | Oil & Gas Operator | Apr 2015 |
| 277 | EOG (Oklahoma) Inc. | Oklahoma City, OK 73112 | Oil & Gas Operator | Oct 2016 |
| 278 | EOG Resources, Inc. | Midland, TX 79702 | Oil & Gas Operator | Feb 2026 |
| 279 | Eott Energy Corporation | Oklahoma City, OK 73118 | Oil & Gas Operator | Dec 1995 |
| 280 | EP Operating LP | Dallas, TX 75201 | Oil & Gas Operator | Mar 2015 |
| 281 | Equipment Lott Inc The | Hennessey, OK 73742-0655 | Oil & Gas Operator | Mar 2008 |
| 282 | Esco Exploration, Inc | Dallas, TX 75201 | Oil & Gas Operator | Mar 2015 |
| 283 | Esenjay Exploration, Inc | Houston, TX 77042 | Oil & Gas Operator | Nov 2025 |
| 284 | Esis Inc | | Oil & Gas Operator | Feb 2017 |
| 285 | Essex Energy Inc | Yukon, OK 73099-5126 | Oil & Gas Operator | Apr 2014 |
| 286 | Evergreen Operating Corp | Denver, CO 80202 | Oil & Gas Operator | Dec 2019 |
| 287 | Evolution Energy LLC | Oklahoma City, OK 73116 | Oil & Gas Operator | Nov 2025 |
| 288 | Excalibur Resources LLC | Houston, TX 77002-5220 | Oil & Gas Operator | Nov 2025 |
| 289 | Excelco Energy Inc. | Kingwood, TX 77339 | Oil & Gas Operator | Jul 2018 |
| 290 | Exxon Mobil Corporation | Spring, TX 77389 | Oil & Gas Operator | Feb 2026 |
| 291 | Exxonmobil Oil Corp | Houston, TX 77210 | Oil & Gas Operator | Sep 2025 |
| 292 | F P C Disposal Inc | El Reno, OK 73036-5501 | Oil Operator | Apr 2003 |
| 293 | Far West Development, LLC | Oklahoma City, OK 73118 | Oil & Gas Operator | Feb 2026 |
| 294 | Faulconer Energy, LLC | Tyler, TX 75711 | Oil & Gas Operator | Feb 2026 |
| 295 | Faulconer, Vernon E., Inc. | Tyler, TX 75711 | Oil & Gas Operator | Dec 2025 |
| 296 | FBF Energy LLC | Tulsa, OK 74120 | Oil & Gas Operator | Dec 2025 |
| 297 | Felix Energy LLC | Denver, CO 80202-1467 | Oil & Gas Operator | Nov 2025 |
| 298 | Femco Services Inc | Lindsay, OK 73052-0632 | Oil & Gas Operator | Nov 2006 |
| 299 | Femco SWD Inc | Enid, OK 73702-3907 | Oil Operator | Mar 2014 |
| 300 | Finley Resources Inc | Fort Worth, TX 76113 | Oil & Gas Operator | Feb 2026 |