| 201 | Export Petroleum Corporation | Fort Worth, TX 76147 | Oil & Gas Operator | May 2025 |
| 202 | Exxon Corporation | Houston, TX 77210 | Oil & Gas Operator | Jun 2024 |
| 203 | Exxon Mobil Corporation | Spring, TX 77389 | Oil & Gas Operator | May 2025 |
| 204 | Exxonmobil Oil Corp | Houston, TX 77210 | Oil & Gas Operator | Feb 2025 |
| 205 | Fina Oil And Chemical Company | Dallas, TX 75221 | Oil & Gas Operator | May 2019 |
| 206 | Finger Oil & Gas, Inc. | Castroville, TX 78009 | Oil & Gas Operator | May 2021 |
| 207 | First Rock, Inc. | Corpus Chrsti, TX 78401 | Oil & Gas Operator | May 2025 |
| 208 | Fischer Operating Corporation | Victoria, TX 77902 | Oil & Gas Operator | Jan 1999 |
| 209 | Five-Jab, Inc. | Tomball, TX 77377 | Oil & Gas Operator | May 2025 |
| 210 | Flat Top Operating, LLC | Midland, TX 79707 | Oil & Gas Operator | May 2025 |
| 211 | Forza Operating, LLC | The Woodlands, TX 77380 | Oil & Gas Operator | May 2025 |
| 212 | Freeport-McMoran Oil & Gas LLC | Houston, TX 77002 | Oil & Gas Operator | Mar 2025 |
| 213 | Fuego Energy, LLC | Fort Worth, TX 76136 | Oil Operator | May 2025 |
| 214 | Gaea Services, Inc. | San Antonio, TX 78216 | Oil & Gas Operator | Sep 2021 |
| 215 | Gardner Energy Corporation | Houston, TX 77024 | Oil & Gas Operator | Mar 1999 |
| 216 | Garrison LTD. | San Antonio, TX 78257 | Oil & Gas Operator | May 2025 |
| 217 | Gasper Rice Resources, LTD. | Houston, TX 77068 | Oil & Gas Operator | May 2025 |
| 218 | Geo-Graphic Production, Inc. | Gonzales, TX 78629 | Oil & Gas Operator | May 2025 |
| 219 | Geosouthern Energy Corporation | The Woodlands, TX 77380 | Oil & Gas Operator | May 2025 |
| 220 | Ginco Operating Co. | San Antonio, TX 78217 | Oil & Gas Operator | May 2025 |
| 221 | Glenco Oil & Gas Company | Seguin, TX 78155 | Oil & Gas Operator | Dec 1994 |
| 222 | Global Training Academy, Inc. | Somerset, TX 78069 | Oil Operator | May 2025 |
| 223 | GN&J LLC | Pharr, TX 78577 | Oil & Gas Operator | May 2025 |
| 224 | Goodnight Midstream Permian, LLC | Dallas, TX 75206 | Oil & Gas Operator | May 2025 |
| 225 | Grand Operating, Inc. | Addison, TX 75001 | Oil & Gas Operator | Dec 2020 |
| 226 | Great Bay Operations, LLC | Portsmouth, NH 03801 | Oil & Gas Operator | Nov 2016 |
| 227 | Great Plains Resources, Inc. | Nixon, TX 78140 | Oil & Gas Operator | May 2025 |
| 228 | Great West Energy & Expl., Inc. | Addison, TX 75001 | Oil & Gas Operator | Mar 2008 |
| 229 | Green Star | Somerset, TX 78069 | Oil Operator | May 2025 |
| 230 | Gsi Oil & Gas, Inc. | Bryan, TX 77806 | Oil & Gas Operator | May 2025 |
| 231 | Guinn Operating Company | Spring Branch, TX 78070 | Oil & Gas Operator | Feb 2014 |
| 232 | Guinn Operating Company, LLC | San Antonio, TX 78260 | Oil Operator | May 2025 |
| 233 | Gulfmark Energy Inc | Houston, TX 77027 | Gas Operator | Apr 2023 |
| 234 | Gulfstar Properties, Inc. | San Antonio, TX 78229 | Oil & Gas Operator | May 2025 |
| 235 | Gulftex Energy III, LP | San Antonio, TX 78257 | Oil & Gas Operator | Jul 2018 |
| 236 | Gulftex Energy IV, LP | San Antonio, TX 78257 | Oil & Gas Operator | Jul 2019 |
| 237 | H & T Oil & Gas Company, Inc. | Alice, TX 78333 | Oil & Gas Operator | Mar 2008 |
| 238 | H&K Energy | Stockdale, TX 78160 | Oil & Gas Operator | Jul 2005 |
| 239 | H. & J. Drilling Company | Fort Worth, TX 76114 | Oil & Gas Operator | Aug 2003 |
| 240 | Hamilton Brothers Oil Co. | Houston, TX 77057 | Oil & Gas Operator | Mar 2015 |
| 241 | Hardwick, Ross H. Oil Company | Devine, TX 78016 | Oil & Gas Operator | May 2025 |
| 242 | Harper Hefte, Inc. | Corpus Chrsti, TX 78410 | Oil & Gas Operator | May 2025 |
| 243 | Harrison Interests, LTD. | Houston, TX 77002 | Oil & Gas Operator | May 2025 |
| 244 | Harvest Petroleum Inc. | Frisco, TX 75033 | Oil & Gas Operator | May 2025 |
| 245 | Harvey Brothers Oil & Gas | Corpus Chrsti, TX 78408 | Oil & Gas Operator | Jul 2004 |
| 246 | Harvey, Mike W. Oil & Gas | Corpus Chrsti, TX 78408 | Oil & Gas Operator | Aug 2003 |
| 247 | Hawthorn Energy Partners, LLC | Nichols Hill, OK 73116 | Oil & Gas Operator | May 2025 |
| 248 | HCM | Dallas, TX 75206 | Oil & Gas Operator | Mar 2015 |
| 249 | Headline Resources, Inc. | Richardson, TX 75080 | Oil & Gas Operator | Aug 1997 |
| 250 | Heartland Resources, Inc. | Temple, TX 76501 | Oil & Gas Operator | Mar 2008 |
| 251 | Henry Petroleum Corp. | Midland, TX 79703 | Oil & Gas Operator | Mar 2001 |
| 252 | Hexp Operating, LLC | Midland, TX 79705 | Oil & Gas Operator | May 2025 |
| 253 | Hilcorp Energy Company | Houston, TX 77208 | Oil & Gas Operator | May 2025 |
| 254 | Hollimon Oil Corporation | Castroville, TX 78009 | Oil & Gas Operator | Nov 2016 |
| 255 | Holloway Oil Company | Austin, TX 78764 | Oil & Gas Operator | Feb 2004 |
| 256 | Hollub, Lambert Drilling Company | Seguin, TX 78155 | Oil & Gas Operator | May 2025 |
| 257 | Home Petroleum Corp | Victoria, TX 77902 | Oil & Gas Operator | May 2025 |
| 258 | Horizon Natural Resources, Inc. | Tulsa, OK 74136 | Oil & Gas Operator | Jan 2019 |
| 259 | Horizon Ridge Oil Company | Austin, TX 78738 | Oil Operator | May 2025 |
| 260 | Howard, Douglas J. | Houston, TX 77070 | Oil & Gas Operator | Mar 2008 |
| 261 | HRB Oil | Houston, TX 77042 | Oil & Gas Operator | Oct 1998 |
| 262 | Hughes, Dan A. Company | Beeville, TX 78104 | Oil & Gas Operator | May 2006 |
| 263 | Humedel Land & Minerals, Inc. | Jourdanton, TX 78026 | Oil & Gas Operator | Mar 2008 |
| 264 | Hunt Oil Company | Dallas, TX 75201 | Oil & Gas Operator | May 2025 |
| 265 | Hunter Petroleum Inc. | Alice, TX 78333 | Oil & Gas Operator | May 2014 |
| 266 | Hunters Creek Oil & Gas | Houston, TX 77042 | Oil & Gas Operator | May 2025 |
| 267 | Huntington Energy LLC | Nichols Hill, OK 73116 | Oil & Gas Operator | May 2025 |
| 268 | Imperial Oil Company | Houston, TX 77073 | Oil & Gas Operator | Oct 2004 |
| 269 | Impetro Operating LLC | Fort Worth, TX 76102 | Oil & Gas Operator | Nov 2020 |
| 270 | Ineos USA Oil & Gas LLC | Denver, CO 80202 | Oil & Gas Operator | May 2025 |
| 271 | Infinity Hydrocarbons LLC | Houston, TX 77079 | Oil & Gas Operator | Aug 2022 |
| 272 | Inland Ocean, Inc. | San Antonio, TX 78205 | Oil & Gas Operator | May 2025 |
| 273 | Inpex Eagle Ford, LLC | San Antonio, TX 78216 | Oil & Gas Operator | Dec 2022 |
| 274 | Ipact | Austin, TX 78734 | Oil & Gas Operator | May 2025 |
| 275 | Island Exploration | Houston, TX 77058 | Oil & Gas Operator | May 2025 |
| 276 | J&J Oil | La Vernia, TX 78121 | Oil & Gas Operator | May 2025 |
| 277 | J-Energy | La Vernia, TX 78121 | Oil & Gas Operator | May 2017 |
| 278 | J.P. Oil Company, Inc. | Midland, TX 79702 | Oil & Gas Operator | May 2025 |
| 279 | Jab Operating, Inc. | San Antonio, TX 78205 | Oil & Gas Operator | Dec 2008 |
| 280 | Jamco Oil | Somerset, TX 78069 | Oil Operator | May 2025 |
| 281 | James, J. W. | Somerset, TX 78069 | Oil & Gas Operator | Aug 2004 |
| 282 | Javelin Energy Partners Management, LLC | Irving, TX 75038 | Oil & Gas Operator | May 2025 |
| 283 | JB Oil & Gas Well Service | Dilley, TX 78017 | Oil & Gas Operator | May 2025 |
| 284 | JD Oil Company | Longview, TX 75605 | Oil & Gas Operator | Sep 2014 |
| 285 | Jenco Petroleum Corporation | The Woodlands, TX 77380 | Oil Operator | May 2025 |
| 286 | Jenex Petroleum Corporation | The Woodlands, TX 77380 | Oil & Gas Operator | May 2025 |
| 287 | JJRS Investments Inc. | Corpus Chrsti, TX 78409 | Oil & Gas Operator | May 2025 |
| 288 | JL Resources, LLC | San Antonio, TX 78217 | Oil & Gas Operator | May 2025 |
| 289 | JM Calk Operating, LLC | Lytle, TX 78052 | Oil Operator | May 2025 |
| 290 | JMD Resources Inc | Belot, OH 44609 | Oil & Gas Operator | Dec 2015 |
| 291 | Johnson Brothers Oil | Bigfoot, TX 78005 | Oil & Gas Operator | May 2025 |
| 292 | JPW Energy, L.L.C. | San Antonio, TX 78216 | Oil & Gas Operator | May 2025 |
| 293 | Jupiter Energy LLC | Richmond, TX 77469 | Oil Operator | May 2025 |
| 294 | K And R Oil Company | Stanton, TX 79782 | Oil & Gas Operator | Aug 2003 |
| 295 | K2 Petroleum, Inc. | San Antonio, TX 78239 | Oil & Gas Operator | May 2025 |
| 296 | Kaiser-Francis Oil Company | Tulsa, OK 74121 | Oil & Gas Operator | May 2025 |
| 297 | Katz Oil Co. | San Antonio, TX 78218 | Oil & Gas Operator | Dec 2002 |
| 298 | Kebo Oil & Gas, Inc. | Portland, TX 78374 | Oil & Gas Operator | May 2025 |
| 299 | Kelpetro, Inc. | Houston, TX 77056 | Oil & Gas Operator | Mar 2012 |
| 300 | Kemco Oil | Alice, TX 78332 | Oil & Gas Operator | Aug 2009 |