| 201 | Costilla Petroleum Corporation | Midland, TX 79702 | Oil & Gas Operator | Mar 2015 |
| 202 | Cox, John L. | Midland, TX 79702 | Oil & Gas Operator | Mar 2015 |
| 203 | CPRP Services LLC | Oklahoma City, OK 73102-5804 | Oil & Gas Operator | Jan 2025 |
| 204 | Crabtree Barbara T | Forney, TX 75126-5818 | Oil & Gas Operator | Oct 2024 |
| 205 | Craig Elder Oil And Gas LLC | Edmond, OK 73013 | Oil & Gas Operator | Jan 2025 |
| 206 | Crane Newton T | | Oil & Gas Operator | Feb 2013 |
| 207 | Crawley Petroleum Corporation | Oklahoma City, OK 73102 | Oil & Gas Operator | Apr 2025 |
| 208 | CRB Resources Inc | Oklahoma City, OK 73118 | Oil & Gas Operator | Jan 2025 |
| 209 | Creslenn Oil Company | | Oil & Gas Operator | Nov 1998 |
| 210 | Crest Resources Inc | Tulsa, OK 74103 | Oil & Gas Operator | Apr 2025 |
| 211 | Cross Timbers Operating Co | Fort Worth, TX 76102 | Oil & Gas Operator | Dec 2024 |
| 212 | Crude Marketing & Trans Inc | Tulsa, OK 74159 | Oil & Gas Operator | Sep 2017 |
| 213 | Crusader Energy Group Inc. | Austin, TX 78746 | Oil & Gas Operator | Mar 2015 |
| 214 | Crusader Energy Group, LLC | Oklahoma City, OK 73142 | Oil & Gas Operator | Mar 2015 |
| 215 | Crusader Energy II, LLC | Oklahoma City, OK 73102 | Oil & Gas Operator | Mar 2015 |
| 216 | Cudd Operating Corp. | Oklahoma City, OK 73118 | Oil & Gas Operator | Apr 2020 |
| 217 | Curzon Operating Company LTD | Oklahoma City, OK 73118-4821 | Oil & Gas Operator | Jan 2025 |
| 218 | D & B Operating, Inc. | Midland, TX 79701 | Oil & Gas Operator | Dec 2003 |
| 219 | D & D Pipe & Equipment Inc | Kingfisher, OK 73750 | Oil & Gas Operator | Mar 2005 |
| 220 | D & J Oil Co | Kermit, TX 79745 | Oil & Gas Operator | Apr 2025 |
| 221 | D & T Swabbing & Well Serv Inc | Hennessey, OK 73742-0124 | Oil & Gas Operator | Jan 2025 |
| 222 | D C Energy, Inc. | Oklahoma City, OK 73134 | Oil & Gas Operator | Apr 2020 |
| 223 | Daco, Inc. | Spearman, TX 79081 | Oil & Gas Operator | Apr 2025 |
| 224 | Dakota Oil Company | Hebbronville, TX 78361 | Oil & Gas Operator | Apr 2025 |
| 225 | Dalen Resources Oil & Gas Co. | Dallas, TX 75206 | Oil & Gas Operator | Jun 2010 |
| 226 | Damson Oil Corporation | Houston, TX 77210 | Oil & Gas Operator | Mar 2005 |
| 227 | Daube Company The | Ardmore, OK 73401 | Oil & Gas Operator | Feb 2025 |
| 228 | Davis & Davis | | Oil & Gas Operator | Dec 2021 |
| 229 | Davis Operating Company | Elysian Field, TX 75642 | Oil & Gas Operator | Apr 2025 |
| 230 | Dawson Resources Inc | Franktown, CO 80116 | Oil & Gas Operator | Mar 2015 |
| 231 | DCP Operating Co LP | Houston, TX 77042 | Oil & Gas Operator | Jan 2025 |
| 232 | Deaton, Gary L. Corporation | Oklahoma City, OK 73105 | Oil & Gas Operator | Mar 2015 |
| 233 | Delong Ralph J | Sapulpa, OK 74066 | Oil & Gas Operator | Nov 2005 |
| 234 | Deminex U.S. Oil Company | | Oil & Gas Operator | Jan 1998 |
| 235 | Denveramerican Petro LLC | | Oil & Gas Operator | May 2006 |
| 236 | Devon Energy Corp (Nevada) | Oklahoma City, OK 73102 | Oil & Gas Operator | Feb 2017 |
| 237 | Devon Energy Operating Corp | Oklahoma City, OK 73102 | Oil & Gas Operator | Apr 2013 |
| 238 | Devon Energy Production Company LP | Oklahoma City, OK 73102 | Oil & Gas Operator | Apr 2025 |
| 239 | Devon Gas Services, L.P. | Oklahoma City, OK 73102 | Oil & Gas Operator | Aug 2023 |
| 240 | Devon Louisiana Corporation | Houston, TX 77002 | Oil & Gas Operator | Oct 2019 |
| 241 | Devon Resources Corporation | Jenks, OK 74037-3525 | Oil & Gas Operator | Dec 2024 |
| 242 | Diamond A Inc. | Tulsa, OK 74137 | Oil & Gas Operator | Jun 2001 |
| 243 | Diamond B Company Inc | Tulsa, OK 74170 | Oil & Gas Operator | Dec 2010 |
| 244 | Diamond Energy Operating Company | Tulsa, OK 74137 | Oil & Gas Operator | Mar 2005 |
| 245 | Diamond Production Company LLC | Irving, TX 75016-7853 | Oil & Gas Operator | Dec 2024 |
| 246 | Dinsmore C E | Enid, OK 73702 | Oil & Gas Operator | May 2009 |
| 247 | Diversified Production LLC | Keithville, LA 71047 | Oil & Gas Operator | Apr 2025 |
| 248 | Dixie Petroleum Inc | Cashion, OK 73016 | Oil & Gas Operator | May 2001 |
| 249 | DKT Energy LLC | Edmond, OK 73083-6844 | Oil & Gas Operator | Sep 2014 |
| 250 | DLB Energy Corporation | Oklahoma City, OK 73118-1401 | Oil & Gas Operator | Dec 2014 |
| 251 | DLB Oil & Gas, Inc. | Big Lake, TX 76932 | Oil & Gas Operator | Apr 2025 |
| 252 | DMS Oil Company | Houston, TX 77042 | Oil & Gas Operator | Jan 2025 |
| 253 | Doco Development Corporation | Norman, OK 73072 | Oil & Gas Operator | Feb 2025 |
| 254 | Dominion Exploration & Production Inc | Houston, TX 77060 | Oil & Gas Operator | Apr 2015 |
| 255 | Dominion Ok TX E & P Inc | Oklahoma City, OK 73134 | Oil & Gas Operator | Nov 2018 |
| 256 | Donaldson Richard E | Bartlesville, OK 74005-0032 | Oil & Gas Operator | Nov 2005 |
| 257 | Double H Petroleum Corporation | Tulsa, OK 74136-5414 | Oil & Gas Operator | May 2006 |
| 258 | Draco Production Company | Tulsa, OK 74133 | Oil & Gas Operator | Jul 2012 |
| 259 | Duncan Oil Properties, Inc. | Oklahoma City, OK 73102 | Oil & Gas Operator | Apr 2025 |
| 260 | Dyco Petroleum Corporation | Tulsa, OK 74103 | Oil & Gas Operator | Mar 2015 |
| 261 | Ea Petroleum Inc | Norman, OK 73072-4147 | Oil & Gas Operator | May 2006 |
| 262 | Eagle Energy PTR I LP | Houston, TX 77064 | Oil & Gas Operator | Feb 2015 |
| 263 | Eagle Exploration Production LLC | Tulsa, OK 74103 | Oil & Gas Operator | Feb 2025 |
| 264 | Eagle Gas Marketing Co | Oklahoma City, OK 73114-2202 | Oil & Gas Operator | Nov 2022 |
| 265 | Eagle Oil & Gas Co. | Dallas, TX 75225 | Oil & Gas Operator | Apr 2025 |
| 266 | Eagle Rock Mid-Continent Operating LLC | Tulsa, OK 74103-3703 | Oil & Gas Operator | Jan 2025 |
| 267 | Earlsboro Energies Corporation | Oklahoma City, OK 73116-3605 | Oil & Gas Operator | Jan 2025 |
| 268 | Edinger Engineering, Inc. | Oklahoma City, OK 73102 | Oil & Gas Operator | Feb 2025 |
| 269 | Edwards & Leach Oil Company | Oklahoma City, OK 73114 | Oil & Gas Operator | Mar 2005 |
| 270 | Eec Inc | Norman, OK 73069-6344 | Oil & Gas Operator | Feb 2025 |
| 271 | Egolf Operating Company | Oklahoma City, OK 73114-7899 | Oil & Gas Operator | Apr 1998 |
| 272 | Eight Round Corporation | Seminole, OK 74818-1482 | Oil & Gas Operator | Jul 2012 |
| 273 | El Paso Production Company | Houston, TX 77002 | Oil & Gas Operator | Mar 2016 |
| 274 | Eland Energy Inc | Dallas, TX 75248 | Oil & Gas Operator | Feb 2025 |
| 275 | Elite Resources Inc | Cleveland, OK 74020 | Oil & Gas Operator | Feb 2025 |
| 276 | Elite Tank Trucks, Inc | | Oil & Gas Operator | Feb 2025 |
| 277 | Emc Exploration Company Inc | Oklahoma City, OK 73103-3775 | Oil & Gas Operator | Jul 2007 |
| 278 | Encino Operating, LLC | Houston, TX 77057 | Oil & Gas Operator | Apr 2025 |
| 279 | Encore Operating LP | Plano, TX 75024 | Oil & Gas Operator | Feb 2025 |
| 280 | Endeavor Natural Gas, LLC | Houston, TX 77002 | Oil & Gas Operator | Feb 2015 |
| 281 | Energex Inc. | Abilene, TX 79604 | Oil & Gas Operator | Apr 2025 |
| 282 | Energy Development Corporation | Houston, TX 77067 | Oil & Gas Operator | Dec 2024 |
| 283 | Energy Production Services LLC | Oklahoma City, OK 73162-4736 | Oil & Gas Operator | Apr 2020 |
| 284 | Enernet Inc | Oklahoma City, OK 73102-8004 | Oil & Gas Operator | Nov 2014 |
| 285 | Enerquest Oil & Gas LLC | Oklahoma City, OK 73114 | Oil & Gas Operator | Jan 2025 |
| 286 | Enervest Operating LLC | Houston, TX 77002 | Oil & Gas Operator | Apr 2025 |
| 287 | Ennex, Inc. | | Oil & Gas Operator | Oct 1993 |
| 288 | Enogex Services Corporation | Oklahoma City, OK 73124-0300 | Oil & Gas Operator | Apr 2009 |
| 289 | Enserch Exploration Inc | Dallas, TX 75206 | Oil & Gas Operator | Apr 2015 |
| 290 | Enterprise Crude Oil LLC | Oklahoma City, OK 73102 | Oil Operator | Aug 2011 |
| 291 | EOG (Oklahoma) Inc. | Oklahoma City, OK 73112 | Oil & Gas Operator | Oct 2016 |
| 292 | EOG Resources, Inc. | Midland, TX 79702 | Oil & Gas Operator | Apr 2025 |
| 293 | Eott Energy Corporation | Oklahoma City, OK 73118 | Oil & Gas Operator | Dec 1995 |
| 294 | EP Operating LP | Dallas, TX 75201 | Oil & Gas Operator | Mar 2015 |
| 295 | Equipment Lott Inc The | Hennessey, OK 73742-0655 | Oil & Gas Operator | Mar 2008 |
| 296 | Esco Exploration, Inc | Dallas, TX 75201 | Oil & Gas Operator | Mar 2015 |
| 297 | Esenjay Exploration, Inc | Houston, TX 77042 | Oil & Gas Operator | Jan 2025 |
| 298 | Esis Inc | | Oil & Gas Operator | Feb 2017 |
| 299 | Essex Energy Inc | Yukon, OK 73099-5126 | Oil & Gas Operator | Apr 2014 |
| 300 | Evergreen Operating Corp | Denver, CO 80202 | Oil & Gas Operator | Dec 2019 |