| 201 | Channel Exploration Company | | Oil & Gas Operator | Feb 1997 |
| 202 | Chanse Energy Corporation | Shreveport, LA 71165-1572 | Oil & Gas Operator | Sep 2021 |
| 203 | Chaparral Energy, Inc. | Oklahoma City, OK 73114 | Oil & Gas Operator | Dec 2009 |
| 204 | Chaparral Energy, L.L.C. | Oklahoma City, OK 73142 | Oil & Gas Operator | Dec 2025 |
| 205 | Chaparral Expl & C L Morris In | | Oil & Gas Operator | Nov 1994 |
| 206 | Chaparral Exploration, Inc. | | Oil & Gas Operator | Jun 2000 |
| 207 | Chaparral Operating, Inc. | Shreveport, LA 71166 | Oil & Gas Operator | Dec 2025 |
| 208 | Charing Cross Properties | | Oil Operator | Aug 1995 |
| 209 | Charles A. O'Niell, Jr. | | Oil & Gas Operator | Apr 2001 |
| 210 | Charles B. Bice | | Oil & Gas Operator | Jul 1983 |
| 211 | Charles E. Mayfield | | Oil & Gas Operator | Mar 2001 |
| 212 | Charles F. Word & Associates | | Oil Operator | Dec 1978 |
| 213 | Charles G. Dannelly | | Oil & Gas Operator | Mar 1998 |
| 214 | Charles Holston, Inc. | | Oil Operator | Jan 2025 |
| 215 | Charles Holston, Inc. Dba GTTS | | Oil Operator | Apr 2009 |
| 216 | Charles M. Nolan | | Oil Operator | Aug 1984 |
| 217 | Charleston Oil & Gas, Inc. | | Oil & Gas Operator | Mar 1997 |
| 218 | Chateau Oil And Gas, Inc. | Dallas, TX 75225 | Oil & Gas Operator | Feb 2017 |
| 219 | CHC Energy, LLC | | Gas Operator | Nov 2012 |
| 220 | Cheniere Petroleum Corporation | | Oil & Gas Operator | Feb 1989 |
| 221 | Chesapeake Operating LLC | Oklahoma City, OK 73154 | Oil & Gas Operator | Dec 2025 |
| 222 | Chesapeake Operating, Inc. | Oklahoma City, OK 73154 | Oil & Gas Operator | Jun 2025 |
| 223 | Chester Floyd | | Oil Operator | Feb 1996 |
| 224 | Chestnut Exploration And Production, Inc | Richardson, TX 78081 | Oil & Gas Operator | Nov 2020 |
| 225 | Chestnut Petroleum, Inc. | Richardson, TX 75080 | Oil & Gas Operator | Nov 2011 |
| 226 | Chevron Pipe Line Company | Houston, TX 77001 | Oil Operator | Feb 2015 |
| 227 | Chevron USA Inc | Midland, TX 79706 | Oil & Gas Operator | Dec 2025 |
| 228 | Chiles Oil Field Supply | | Oil & Gas Operator | Jan 2025 |
| 229 | Chinn Exploration Company | Longview, TX 75605 | Oil & Gas Operator | Nov 2015 |
| 230 | Chisos, LTD | Houston, TX 77098 | Oil & Gas Operator | Dec 2025 |
| 231 | Cholla Resources, Inc. | Denver, CO 80202 | Oil & Gas Operator | Jan 1997 |
| 232 | Christeve Oil Company, Inc. | Houston, TX 77068 | Oil & Gas Operator | Dec 2022 |
| 233 | Christopher Oil & Gas Inc | Fulshear, TX 77441 | Oil & Gas Operator | Apr 2015 |
| 234 | Chroma Operating, Inc. | Washington, DC 20036 | Oil & Gas Operator | Jun 2016 |
| 235 | Churchill Energy, Inc. | | Oil & Gas Operator | Aug 2020 |
| 236 | Cibco Resources, LLC | | Oil & Gas Operator | Nov 2024 |
| 237 | Cibolo Energy Operating, Inc. | Bulverde, TX 78163 | Oil & Gas Operator | Dec 2025 |
| 238 | Cico Oil & Gas Company | Houston, TX 77057 | Oil & Gas Operator | Aug 2019 |
| 239 | Ciera Resources, Inc. | | Gas Operator | Nov 1998 |
| 240 | Cimarex Energy Co | Midland, TX 79706 | Oil & Gas Operator | Dec 2025 |
| 241 | Cimarex Energy Co. Of Colorado | Midland, TX 79706 | Oil & Gas Operator | Dec 2025 |
| 242 | Cimic Energy, LLC | | Oil Operator | Jan 2025 |
| 243 | Cinder Production Company | | Oil & Gas Operator | Apr 2014 |
| 244 | Cisco Petroleum, Inc. | | Oil & Gas Operator | Oct 2010 |
| 245 | Citation Oil & Gas Corp | Houston, TX 77269 | Oil & Gas Operator | Dec 2025 |
| 246 | Cities Service Company | | Oil & Gas Operator | Mar 1983 |
| 247 | Cities Service Oil & Gas Corp | | Oil & Gas Operator | Mar 1988 |
| 248 | Cities Service Oil Co. | | Oil & Gas Operator | Dec 1986 |
| 249 | Cits BK & Trust Of Springhill | | Oil & Gas Operator | Jun 1990 |
| 250 | Civego, Inc. | | Oil & Gas Operator | Jul 1994 |
| 251 | Clarence F. Routon, Jr. | | Oil Operator | Apr 1990 |
| 252 | Clark Oil Producing Company | | Oil & Gas Operator | Oct 1979 |
| 253 | Claron Corporation | Houston, TX 77219 | Oil & Gas Operator | Dec 2025 |
| 254 | Classic Hydrocarbons, Inc. | | Gas Operator | Dec 2007 |
| 255 | Classic Oil & Gas, Inc. | Tyler, TX 75701 | Oil & Gas Operator | Jan 2004 |
| 256 | Claude Debeaux, Jr. Et Al | | Oil Operator | Dec 1999 |
| 257 | Claude S. Hinds | | Oil Operator | Aug 1985 |
| 258 | Clayton W. Williams, Jr. | | Oil & Gas Operator | Sep 1986 |
| 259 | Clayton W. Williams, Jr., Inc. | | Oil & Gas Operator | May 1993 |
| 260 | Clayton Williams Energy, Inc. | Houston, TX 77070 | Oil & Gas Operator | Apr 2017 |
| 261 | Clear Lake Oil Co. | | Oil Operator | Jan 2025 |
| 262 | Clearly Petroleum, LLC | Houston, TX 77086 | Oil & Gas Operator | Jun 2020 |
| 263 | Clements Energy, Inc. | | Oil & Gas Operator | Oct 1987 |
| 264 | Clements-B & MCK - Luffey | | Gas Operator | Apr 1979 |
| 265 | Click Corp | Monroe, LA 71207 | Oil & Gas Operator | Jan 2025 |
| 266 | Cliffs Drilling Company | | Oil & Gas Operator | Dec 1984 |
| 267 | Cliffs Oil And Gas Company | | Oil & Gas Operator | Oct 1997 |
| 268 | Cliffwood Production Co. | Houston, TX 77090 | Oil & Gas Operator | Aug 2013 |
| 269 | CLK Energy Partners, LLC | | Oil & Gas Operator | Aug 2018 |
| 270 | Clovelly DRLG & Dev Co Inc | | Oil & Gas Operator | Oct 1983 |
| 271 | Clovelly Oil Co. LLC | | Oil & Gas Operator | Nov 2024 |
| 272 | Clovelly Oil Co., Inc. | | Oil & Gas Operator | Nov 2008 |
| 273 | Clovelly Oil Co., Inc. - Ripco | | Oil & Gas Operator | Nov 1991 |
| 274 | Clover Energy Corp | | Oil & Gas Operator | May 1980 |
| 275 | CM Oil Co., L.L.C. | | Oil Operator | Jan 2025 |
| 276 | CMS Nomeco Oil & Gas Co. | Jackson, MI 49201 | Oil & Gas Operator | Jan 2015 |
| 277 | CMS Oil And Gas Company | Jackson, MI 49201 | Oil & Gas Operator | Oct 2002 |
| 278 | CNC Oil Co., Inc. | | Oil Operator | Aug 1991 |
| 279 | CNG Producing Co.-Tulsa Div. | | Oil & Gas Operator | Jun 1986 |
| 280 | CNG Producing Company | New Orleans, LA 70112 | Oil & Gas Operator | Dec 2015 |
| 281 | CNR Resources Inc | Houston, TX 77002-4103 | Oil & Gas Operator | May 2005 |
| 282 | Co-Wil-Co, Incorporated | | Oil Operator | Dec 1990 |
| 283 | Coalinga Corporation | Houston, TX 77002 | Oil & Gas Operator | May 1999 |
| 284 | Coast Exploration Co. | | Oil & Gas Operator | Nov 1997 |
| 285 | Coastal Management Corporation | Midland, TX 79702 | Oil & Gas Operator | Mar 2008 |
| 286 | Coastal Minerals, Inc. | | Oil Operator | Aug 1991 |
| 287 | Coastal Oil & Gas Corp | Houston, TX 77252 | Oil & Gas Operator | Dec 2009 |
| 288 | Coastal Plains Exploration, LLC | Port Lavaca, TX 77979 | Oil & Gas Operator | Dec 2025 |
| 289 | Coastal Production Inc. | | Oil & Gas Operator | Aug 2000 |
| 290 | Coastal States & Emerald Oil | | Oil & Gas Operator | Dec 1979 |
| 291 | Coastal States Gas Prod Co | | Oil & Gas Operator | Jun 1996 |
| 292 | Cobra Oil & Gas Corporation | Wichita Falls, TX 76307 | Oil & Gas Operator | Dec 2025 |
| 293 | Cobra-Lyons-Hilliard-Watson | | Oil & Gas Operator | Jun 1992 |
| 294 | Cochon Properties, LLC | | Oil & Gas Operator | Aug 2016 |
| 295 | Cockrell Oil Corporation | Houston, TX 77002-7348 | Oil & Gas Operator | Feb 2001 |
| 296 | Coda Energy, Inc. | Dallas, TX 75231 | Oil & Gas Operator | Aug 1998 |
| 297 | Cody C. Beasley | | Oil & Gas Operator | Apr 1987 |
| 298 | Cody Energy LLC | Houston, TX 77024 | Oil & Gas Operator | Jun 2020 |
| 299 | Cody Energy, Inc. | Houston, TX 77077 | Oil & Gas Operator | Oct 2025 |
| 300 | Cohen & Kosovitz | | Oil & Gas Operator | May 1998 |