| 201 | Eex Corporation | Houston, TX 77060 | Oil & Gas Operator | Feb 2000 |
| 202 | Eex E&P Company, L.P. | Houston, TX 77060 | Oil & Gas Operator | Jul 2003 |
| 203 | Eex Operating, L.P. | Houston, TX 77060 | Oil & Gas Operator | Jul 2003 |
| 204 | El Paso Production Company | Houston, TX 77002 | Oil & Gas Operator | Mar 2016 |
| 205 | El Paso Production Oil & Gas Co. | Houston, TX 77252 | Oil & Gas Operator | Jul 2025 |
| 206 | Eland Energy Inc | Dallas, TX 75248 | Oil & Gas Operator | May 2025 |
| 207 | Elk Energy Holdings LLC | Wichita, KS 67226 | Oil & Gas Operator | Mar 2025 |
| 208 | Elliott Oil & Gas Company | The Woodlands, TX 77380 | Oil & Gas Operator | Sep 2006 |
| 209 | Elliott Oil & Gas Operating Co. | Magnolia, TX 77354 | Oil & Gas Operator | Jul 2025 |
| 210 | Ellsworth, H. P. O&G Properties | Corpus Chrsti, TX 78413 | Oil & Gas Operator | Jul 2025 |
| 211 | Encana Oil & Gas (USA) Inc. | Denver, CO 80202 | Oil & Gas Operator | Oct 2020 |
| 212 | Endeavor Natural Gas, LLC | Houston, TX 77002 | Oil & Gas Operator | Feb 2015 |
| 213 | Endeavor Natural Gas, LP | Houston, TX 77002 | Oil & Gas Operator | Jul 2025 |
| 214 | Energy 2000, Inc. | Reno, NV 89501 | Oil & Gas Operator | Jul 2025 |
| 215 | Energy Development Corporation | Houston, TX 77067 | Oil & Gas Operator | Dec 2024 |
| 216 | Energy Partners, LTD. | New Orleans, LA 70170 | Oil & Gas Operator | Aug 2012 |
| 217 | Energy Transfer Crude Marketing LLC | Dallas, TX 75225 | Oil Operator | Mar 2025 |
| 218 | Engelke, R. H. | San Antonio, TX 78230 | Oil & Gas Operator | Jul 2025 |
| 219 | Enpower Resources Inc. | Sugar Land, TX 77479 | Oil & Gas Operator | Jul 2025 |
| 220 | Enre Corp. | San Antonio, TX 78209 | Oil & Gas Operator | Mar 2005 |
| 221 | Enre LP | Kingwood, TX 77339 | Oil & Gas Operator | Feb 2004 |
| 222 | Enserch Exploration Inc | Dallas, TX 75206 | Oil & Gas Operator | Apr 2015 |
| 223 | EOG Resources, Inc. | Midland, TX 79702 | Oil & Gas Operator | Jul 2025 |
| 224 | EP Operating Limited Partnership | Dallas, TX 75201 | Oil & Gas Operator | Feb 1995 |
| 225 | Ermis Vacuum Service | El Campo, TX 77437 | Oil & Gas Operator | Mar 2010 |
| 226 | Ermis Vacuum Service, LLC | El Campo, TX 77437 | Oil & Gas Operator | Jul 2025 |
| 227 | Ernest Operating Company | Rockdale, TX 76567 | Oil & Gas Operator | Jul 2025 |
| 228 | Esenjay Petroleum Corp. | Corpus Chrsti, TX 78471 | Oil & Gas Operator | Jul 1998 |
| 229 | Espada Operating LLC | San Antonio, TX 78209 | Oil Operator | Jul 2025 |
| 230 | Etoco, L.P. | Houston, TX 77002 | Oil & Gas Operator | Jul 2025 |
| 231 | Evans, Julian | Houston, TX 77024 | Oil & Gas Operator | Nov 1995 |
| 232 | Evans, S. Lavon Jr. Oper. Co. | Laurel, MS 39442 | Oil & Gas Operator | Jul 2025 |
| 233 | Everest Resource Company | Corpus Chrsti, TX 78403 | Oil & Gas Operator | Jul 2025 |
| 234 | Evergreen Energy, Inc | Houston, TX 77098 | Oil & Gas Operator | Jul 2025 |
| 235 | Exp, Inc. | Dallas, TX 75244 | Oil & Gas Operator | May 2003 |
| 236 | Express Oil Co. | Hallettsville, TX 77964 | Oil & Gas Operator | Jul 2025 |
| 237 | Exxcel Operating Company | San Antonio, TX 78227 | Oil & Gas Operator | Jul 2025 |
| 238 | Exxon Corporation | Houston, TX 77210 | Oil & Gas Operator | Jun 2024 |
| 239 | Exxon Mobil Corporation | Spring, TX 77389 | Oil & Gas Operator | Jul 2025 |
| 240 | Falcon Bay Operations, LLC | Midland, TX 79701 | Oil & Gas Operator | Oct 2007 |
| 241 | Faulconer Energy, LLC | Tyler, TX 75711 | Oil & Gas Operator | Jul 2025 |
| 242 | Faulconer Vernon E Inc | Tyler, TX 75711 | Oil & Gas Operator | May 2025 |
| 243 | Ffa Petroleum Services | Victoria, TX 77903 | Oil & Gas Operator | Sep 2001 |
| 244 | Field Petroleum Corp. | San Antonio, TX 78216 | Oil & Gas Operator | Jul 2025 |
| 245 | Fieldwood Onshore LLC | Houston, TX 77098 | Oil & Gas Operator | Jul 2025 |
| 246 | Finaly Resources LLC | Sunset Beach, CA 90742 | Oil & Gas Operator | Jul 2025 |
| 247 | Finley Resources Inc | Fort Worth, TX 76113 | Oil & Gas Operator | Jul 2025 |
| 248 | First Aransas Reserves, Inc. | Alvin, TX 77511 | Oil & Gas Operator | Mar 2018 |
| 249 | Five-Jab, Inc. | Tomball, TX 77377 | Oil & Gas Operator | Jul 2025 |
| 250 | Fletcher Operating, LLC | Fairhope, AL 36532 | Oil & Gas Operator | Jul 2025 |
| 251 | Floex Energy LLC | Tyler, TX 75701 | Oil Operator | Jul 2025 |
| 252 | Flow Energy Inc. | Bellaire, TX 77401 | Oil & Gas Operator | Sep 1996 |
| 253 | Forbes, C. C. Company | Alice, TX 78333 | Oil & Gas Operator | Sep 2015 |
| 254 | Forcenergy Onshore Inc. | Houston, TX 77002 | Oil & Gas Operator | Dec 2012 |
| 255 | Forest Oil Corporation | Houston, TX 77002 | Oil & Gas Operator | Mar 2015 |
| 256 | Forney & McCombs | Houston, TX 77056 | Oil & Gas Operator | Jan 1998 |
| 257 | Forney Oil Corporation | Houston, TX 77056 | Oil & Gas Operator | Jan 1998 |
| 258 | Forrest Energy, LLC | Hattiesburg, MS 39401 | Oil & Gas Operator | Feb 1998 |
| 259 | Fort Apache Energy, Inc. | Boerne, TX 78015 | Oil & Gas Operator | Jul 2025 |
| 260 | Fortune Resources LLC | Longview, TX 75604 | Oil & Gas Operator | Jul 2025 |
| 261 | Forza Operating, LLC | The Woodlands, TX 77380 | Oil & Gas Operator | Jul 2025 |
| 262 | Foundation Oil Company, Inc. | Kingwood, TX 77325 | Oil & Gas Operator | Jul 2025 |
| 263 | Fredco | Louise, TX 77455 | Oil & Gas Operator | Jul 2025 |
| 264 | Fredonia Resources Inc. | Longview, TX 75606 | Oil & Gas Operator | Aug 2003 |
| 265 | Frio Engineering Inc. | Houston, TX 77066 | Oil & Gas Operator | Jul 2025 |
| 266 | Fuji Resources Production Co,Inc | Houston, TX 77036 | Oil & Gas Operator | Feb 2000 |
| 267 | Future Petroleum Company LLC | Houston, TX 77027 | Oil & Gas Operator | Jun 2013 |
| 268 | Future Petroleum Corporation | Houston, TX 77002 | Oil & Gas Operator | Sep 1999 |
| 269 | G & W Production Company L.L.C. | El Campo, TX 77437 | Oil Operator | May 2017 |
| 270 | G E Operating, Inc. | Graham, TX 76450 | Oil & Gas Operator | May 2020 |
| 271 | G.R.P. Gauging, Inc. | Wharton, TX 77488 | Oil & Gas Operator | Oct 2010 |
| 272 | Gaither Petroleum Corporation | Katy, TX 77493 | Oil & Gas Operator | Jul 2025 |
| 273 | Galloway Lone Star, L.L.C. | Tomball, TX 77377 | Oil & Gas Operator | Jul 2025 |
| 274 | Gardner Energy Corporation | Houston, TX 77024 | Oil & Gas Operator | Mar 1999 |
| 275 | Garrison LTD. | San Antonio, TX 78257 | Oil & Gas Operator | Jul 2025 |
| 276 | Gasper Rice Resources, LTD. | Houston, TX 77068 | Oil & Gas Operator | Jul 2025 |
| 277 | Gcer Onshore, LLC | Houston, TX 77002 | Oil & Gas Operator | Dec 2015 |
| 278 | Gec Operating, Inc. | Houston, TX 77024 | Oil & Gas Operator | Jul 2025 |
| 279 | Gemarmi Inc. | Cypress, TX 77433 | Oil & Gas Operator | Jul 2025 |
| 280 | General Oil Company, Inc. | Wichita, KS 67213 | Oil & Gas Operator | Jul 2025 |
| 281 | Geodominion Petroleum | Corpus Chrsti, TX 78403 | Oil & Gas Operator | May 2012 |
| 282 | Geodyne Operating Company | Tulsa, OK 74103 | Oil & Gas Operator | Jun 2015 |
| 283 | Geosouthern Energy Corporation | The Woodlands, TX 77380 | Oil & Gas Operator | Jul 2025 |
| 284 | Gillring Oil Company | Fort Worth, TX 76102 | Oil & Gas Operator | May 1994 |
| 285 | Glenn, Wayne E. & Assoc., Inc. | Dickinson, TX 77539 | Oil & Gas Operator | Jun 2005 |
| 286 | Goldenrod Gas, Inc. | Victoria, TX 77904 | Gas Operator | Jul 2025 |
| 287 | Goldking Operating Company, Inc. | Houston, TX 77002 | Oil & Gas Operator | Jun 2007 |
| 288 | Goldking Prod. Co. | Houston, TX 77002 | Oil & Gas Operator | Apr 1998 |
| 289 | Goldston Oil Corporation | Houston, TX 77257 | Oil & Gas Operator | Jul 2025 |
| 290 | Goliad Operating Company | Houston, TX 77265 | Oil & Gas Operator | Aug 2003 |
| 291 | Grace Petroleum Corp. | Tulsa, OK 74103 | Oil & Gas Operator | Oct 1997 |
| 292 | Grand Resources Inc | Tulsa, OK 74137 | Oil & Gas Operator | Jul 2025 |
| 293 | Great Western Drilling Co | Midland, TX 79701 | Oil & Gas Operator | Jul 2025 |
| 294 | Great Western Onshore Inc | Houston, TX 77002 | Oil & Gas Operator | Mar 2008 |
| 295 | Green Exploration Company | Austin, TX 78711 | Oil & Gas Operator | Jul 2025 |
| 296 | Greenhill Petroleum Corporation | Houston, TX 77077 | Oil & Gas Operator | Jan 1998 |
| 297 | Gruy Petroleum Management Co. | Irving, TX 75014 | Oil & Gas Operator | Nov 2014 |
| 298 | Gulf States Production Company | Houston, TX 77027 | Oil & Gas Operator | Aug 1997 |
| 299 | Gulfstar Properties, Inc. | San Antonio, TX 78229 | Oil & Gas Operator | Jul 2025 |
| 300 | H & S Production, Inc. | Dallas, TX 75252 | Oil & Gas Operator | Mar 2004 |