| 201 | Desco Oil Company | Houston, TX 77056 | Oil & Gas Operator | Feb 2017 |
| 202 | Devon Energy Production Company LP | Oklahoma City, OK 73102 | Oil & Gas Operator | Apr 2025 |
| 203 | Devon Louisiana Corporation | Houston, TX 77002 | Oil & Gas Operator | Oct 2019 |
| 204 | Dewbre Petroleum Corporation | Corpus Chrsti, TX 78404 | Oil & Gas Operator | Apr 2025 |
| 205 | Dinero Oil Corporation | Corpus Chrsti, TX 78460 | Oil & Gas Operator | Nov 1999 |
| 206 | Dirks, R. W. | Tuleta, TX 78162 | Oil & Gas Operator | May 1999 |
| 207 | Dirks, R.W. Pet. Eng. Inc. | Tuleta, TX 78162 | Oil & Gas Operator | Jul 1999 |
| 208 | Dirnett, Inc. | Tuleta, TX 78162 | Oil & Gas Operator | Apr 2025 |
| 209 | Discorbis Oil Company | San Antonio, TX 78217 | Oil & Gas Operator | Jul 2019 |
| 210 | Discovery Energy Corp. CC | Corpus Chrsti, TX 78403 | Oil & Gas Operator | Apr 2025 |
| 211 | Discovery Petroleum, L.L.C. | Alice, TX 78333 | Oil & Gas Operator | Apr 2025 |
| 212 | Dominion Exploration & Production Inc | Houston, TX 77060 | Oil & Gas Operator | Apr 2015 |
| 213 | Dominion Minerals Corporation | Houston, TX 77014 | Oil & Gas Operator | Nov 2009 |
| 214 | Dominion Oklahoma Texas E&P, Inc | Richmond, VA 23219 | Oil & Gas Operator | Sep 2018 |
| 215 | Dorado Oil Company | Corpus Chrsti, TX 78403 | Oil & Gas Operator | Dec 2014 |
| 216 | Double Eagle Petroleum Corp | Evansville, IN 47725 | Oil & Gas Operator | Apr 2025 |
| 217 | Double Play Oil & Gas, Inc | Portland, TX 78374 | Oil & Gas Operator | Apr 2025 |
| 218 | Dreyfus, Louis Natural Gas Corp | Oklahoma City, OK 73134 | Oil & Gas Operator | Nov 2001 |
| 219 | DSW Production Corp. | Houston, TX 77265 | Oil & Gas Operator | Apr 2025 |
| 220 | Durst Oil Company | Corpus Chrsti, TX 78477 | Oil & Gas Operator | Sep 2000 |
| 221 | Dynamic Production, Inc. | Fort Worth, TX 76106 | Oil & Gas Operator | Apr 2025 |
| 222 | E.G. Operating | Dallas, TX 75206 | Oil & Gas Operator | Mar 2008 |
| 223 | E.G.L. Resources, Inc. | Midland, TX 79702 | Oil & Gas Operator | Feb 2025 |
| 224 | Edco Energy, Inc. | Austin, TX 78738 | Oil & Gas Operator | May 2003 |
| 225 | Edge Petroleum Corporation | Houston, TX 77002 | Oil & Gas Operator | Jun 1999 |
| 226 | Edge Petroleum Oper. Co., Inc. | Houston, TX 77042 | Oil & Gas Operator | Nov 2010 |
| 227 | Edinger Inc. | Oklahoma City, OK 73102 | Oil & Gas Operator | Jun 2007 |
| 228 | Eex E&P Company, L.P. | Houston, TX 77060 | Oil & Gas Operator | Jul 2003 |
| 229 | Eex Operating, L.P. | Houston, TX 77060 | Oil & Gas Operator | Jul 2003 |
| 230 | Egan Resources Inc. | Katy, TX 77494 | Oil & Gas Operator | Oct 2016 |
| 231 | El Paso Production Oil & Gas Co. | Houston, TX 77252 | Oil & Gas Operator | Apr 2025 |
| 232 | Elliott Oil & Gas Company | The Woodlands, TX 77380 | Oil & Gas Operator | Sep 2006 |
| 233 | Ellsworth, H. P. O&G Properties | Corpus Chrsti, TX 78413 | Oil & Gas Operator | Apr 2025 |
| 234 | Emerald Oil & Gas LC | Fort Worth, TX 76109 | Oil & Gas Operator | Apr 2025 |
| 235 | Enercorp Resources, Inc. | Houston, TX 77027 | Oil & Gas Operator | Dec 1993 |
| 236 | Energy Resource Management, Inc. | Caldwell, TX 77836 | Oil & Gas Operator | Mar 2008 |
| 237 | Energy Transfer Crude Marketing LLC | Houston, TX 77002 | Oil Operator | Jan 2025 |
| 238 | Energyquest II, LLC | The Woodlands, TX 77381 | Oil & Gas Operator | Jan 2025 |
| 239 | Enerquest Oil & Gas LLC | Oklahoma City, OK 73114 | Oil & Gas Operator | Jan 2025 |
| 240 | Enex Resources Corporation | Houston, TX 77002 | Oil & Gas Operator | Dec 2009 |
| 241 | Engroup Resources, L.P. | Houston, TX 77002 | Oil & Gas Operator | Apr 2025 |
| 242 | Enron Oil & Gas Company | Houston, TX 77210 | Oil & Gas Operator | Dec 1999 |
| 243 | Enserch Exploration Inc | Dallas, TX 75206 | Oil & Gas Operator | Apr 2015 |
| 244 | EP Operating Limited Partnership | Dallas, TX 75201 | Oil & Gas Operator | Feb 1995 |
| 245 | Erg Operating Company Inc | Houston, TX 77002 | Oil & Gas Operator | Dec 2006 |
| 246 | Erg Resources LLC | Houston, TX 77002 | Oil & Gas Operator | Oct 2015 |
| 247 | Erskine Energy, LLC | H SPG NTL PK, AR 71909 | Oil & Gas Operator | Apr 2025 |
| 248 | Erskine Operating LLC | Houston, TX 77079 | Oil & Gas Operator | Dec 2007 |
| 249 | Escondido Petroleum Company, Inc | Houston, TX 77063 | Oil & Gas Operator | Apr 2025 |
| 250 | Esenjay Exploration, Inc | Houston, TX 77042 | Oil & Gas Operator | Jan 2025 |
| 251 | Esenjay Petroleum Corp. | Corpus Chrsti, TX 78471 | Oil & Gas Operator | Jul 1998 |
| 252 | Estate Of James L. Nelson | Pettus, TX 78146 | Oil & Gas Operator | Apr 2025 |
| 253 | Etoco Incorporated | Houston, TX 77002 | Oil & Gas Operator | May 2005 |
| 254 | Etoco, L.P. | Houston, TX 77002 | Oil & Gas Operator | Apr 2025 |
| 255 | Everest Minerals Corp. | Corpus Chrsti, TX 78403 | Oil & Gas Operator | Apr 2001 |
| 256 | Everest Resource Company | Corpus Chrsti, TX 78403 | Oil & Gas Operator | Apr 2025 |
| 257 | Export Petroleum Corporation | Fort Worth, TX 76147 | Oil & Gas Operator | Apr 2025 |
| 258 | Express Oil Co. | Hallettsville, TX 77964 | Oil & Gas Operator | Apr 2025 |
| 259 | Extenergy, L.P. | The Woodlands, TX 77380 | Oil & Gas Operator | Dec 2014 |
| 260 | Exxon Corporation | Houston, TX 77210 | Oil & Gas Operator | Jun 2024 |
| 261 | F & M Oil Company Inc | Pettus, TX 78146 | Oil & Gas Operator | Apr 2025 |
| 262 | Faulconer Energy, LLC | Tyler, TX 75711 | Oil & Gas Operator | Apr 2025 |
| 263 | Faulconer Vernon E Inc | Tyler, TX 75711 | Oil & Gas Operator | Feb 2025 |
| 264 | Fina Oil And Chemical Company | Dallas, TX 75221 | Oil & Gas Operator | May 2019 |
| 265 | Finaly Resources LLC | Sunset Beach, CA 90742 | Oil & Gas Operator | Apr 2025 |
| 266 | Firstrike Energy Corporation | Cleburne, TX 76033 | Oil & Gas Operator | Jan 2025 |
| 267 | Fletcher Operating, LLC | Fairhope, AL 36532 | Oil & Gas Operator | Apr 2025 |
| 268 | Flint Interests, LLC | Houston, TX 77057 | Oil & Gas Operator | Apr 2025 |
| 269 | Flournoy Production Co. | Alice, TX 78333 | Oil & Gas Operator | Dec 2002 |
| 270 | Forbes, C. C. Company | Alice, TX 78333 | Oil & Gas Operator | Sep 2015 |
| 271 | Forest Oil Corporation | Houston, TX 77002 | Oil & Gas Operator | Mar 2015 |
| 272 | Fox, Hewitt B., Inc. | Corpus Chrsti, TX 78411 | Oil & Gas Operator | Apr 2025 |
| 273 | Freddy'S Well Service, Inc. | Victoria, TX 77902 | Oil & Gas Operator | Apr 2025 |
| 274 | Freeman, James C. | Corpus Chrsti, TX 78403 | Oil & Gas Operator | Sep 2000 |
| 275 | Frio Exploration Company | Pearland, TX 77588 | Oil & Gas Operator | Dec 2000 |
| 276 | Frio Production Co. | Alice, TX 78333 | Oil & Gas Operator | Sep 1998 |
| 277 | Gaither Petroleum Corporation | Katy, TX 77493 | Oil & Gas Operator | Apr 2025 |
| 278 | Gardner Energy Corporation | Houston, TX 77024 | Oil & Gas Operator | Mar 1999 |
| 279 | Gastex, Inc. | Midland, TX 79710 | Oil & Gas Operator | Mar 1995 |
| 280 | Gec Operating, Inc. | Houston, TX 77024 | Oil & Gas Operator | Apr 2025 |
| 281 | Geiser Operating, Inc. | Portland, TX 78374 | Oil & Gas Operator | Sep 2019 |
| 282 | Geiser, D. Allen | Portland, TX 78374 | Oil & Gas Operator | Oct 2005 |
| 283 | Gemarmi Inc. | Cypress, TX 77433 | Oil & Gas Operator | Apr 2025 |
| 284 | Genesis Crude Oil LP | Houston, TX 77002 | Oil & Gas Operator | Apr 2000 |
| 285 | Geo Energy & Compression, Inc. | Corpus Chrsti, TX 78404 | Oil & Gas Operator | Dec 2012 |
| 286 | Geodominion Petroleum | Corpus Chrsti, TX 78403 | Oil & Gas Operator | May 2012 |
| 287 | Geonatural Resources, Inc. | Dallas, TX 75240 | Oil & Gas Operator | Apr 2025 |
| 288 | Gillring Oil Company | Fort Worth, TX 76102 | Oil & Gas Operator | May 1994 |
| 289 | Gilster, Ralph R. III | Victoria, TX 77901 | Oil & Gas Operator | Jun 2004 |
| 290 | Go-Energy Co. | San Antonio, TX 78232 | Oil & Gas Operator | Mar 2002 |
| 291 | Gohlke Farms, Inc. | Corpus Chrsti, TX 78418 | Oil & Gas Operator | Aug 2011 |
| 292 | Goldking Prod. Co. | Houston, TX 77002 | Oil & Gas Operator | Apr 1998 |
| 293 | Goliad Holdings, LLC | Columbia, MS 39429 | Gas Operator | Oct 2020 |
| 294 | Goliad Operating Company | Houston, TX 77265 | Oil & Gas Operator | Aug 2003 |
| 295 | Grace Petroleum Corp. | Tulsa, OK 74103 | Oil & Gas Operator | Oct 1997 |
| 296 | Great West Energy & Expl., Inc. | Addison, TX 75001 | Oil & Gas Operator | Mar 2008 |
| 297 | Great Western Onshore Inc | Houston, TX 77002 | Oil & Gas Operator | Mar 2008 |
| 298 | Griffin Petroleum Company | Midland, TX 79705 | Oil & Gas Operator | Apr 2025 |
| 299 | Gruy Petroleum Management Co. | Irving, TX 75014 | Oil & Gas Operator | Nov 2014 |
| 300 | Gulf States Production Company | Houston, TX 77027 | Oil & Gas Operator | Aug 1997 |