| 301 | Alpha Petrovision Us Inc | Canada, 00100 | Oil & Gas Operator | May 2013 |
| 302 | Alpine Exploration Co, Inc. | Dallas, TX 75360 | Oil & Gas Operator | Nov 2017 |
| 303 | Alpine Gas Company, LLC | Dallas, TX 75201 | Oil & Gas Operator | Oct 2006 |
| 304 | Alpine Petroleum | Abilene, TX 79608 | Oil & Gas Operator | Jul 2018 |
| 305 | Alpine Resources, Inc. | Houston, TX 77002 | Oil & Gas Operator | Mar 2008 |
| 306 | Alps Oil Company | Odessa, TX 79760 | Oil & Gas Operator | Aug 1999 |
| 307 | Alta Energy Corporation | Midland, TX 79701 | Oil & Gas Operator | Apr 1995 |
| 308 | Alta Mesa Services, LP | Houston, TX 77084 | Oil & Gas Operator | Aug 2024 |
| 309 | Altair Energy Corp. | Tyler, TX 75702 | Oil & Gas Operator | Jun 1994 |
| 310 | Altalay STX LLC | San Juan, PR 00968 | Oil & Gas Operator | Aug 2024 |
| 311 | Altex Resources, Inc. | Carney, OK 74832 | Oil & Gas Operator | Mar 2015 |
| 312 | Altman Energy, Inc. | Tulsa, OK 74114 | Oil & Gas Operator | Aug 2024 |
| 313 | Alto Minerals, Inc. | Midland, TX 79708 | Oil & Gas Operator | Apr 2019 |
| 314 | Altura Energy LTD. | Houston, TX 77210 | Oil & Gas Operator | Apr 2000 |
| 315 | Alumni Oil LLC | Plano, TX 75024 | Oil Operator | Aug 2024 |
| 316 | Alvarado 2014 LLC | Houston, TX 77027 | Oil & Gas Operator | Aug 2024 |
| 317 | Alyaha Energy, LLC | Dumas, TX 79029 | Gas Operator | Aug 2024 |
| 318 | Alyana Energy Corporation | Houston, TX 77227 | Oil & Gas Operator | Apr 1995 |
| 319 | Alyndson Oil & Gas Inc. | Alice, TX 78333 | Oil & Gas Operator | Jun 2000 |
| 320 | Amac Energy, L.L.C. | The Woodlands, TX 77381 | Oil & Gas Operator | Aug 2024 |
| 321 | Amarillo Exploration, Inc. | Dallas, TX 75360 | Oil & Gas Operator | Aug 2024 |
| 322 | Amarillo Natural Gas, Inc. | Amarillo, TX 79119 | Gas Operator | Jul 1996 |
| 323 | Amax Oil & Gas Inc | Fort Worth, TX 76107 | Oil & Gas Operator | Nov 2014 |
| 324 | Amazon Royalties, Inc. | Fulshear, TX 77441 | Oil & Gas Operator | Aug 2024 |
| 325 | Ambassador Oil Company, LLC | Abilene, TX 79604 | Oil & Gas Operator | Aug 2024 |
| 326 | Ambassador Petroleum, Inc. | Katy, TX 77494 | Oil & Gas Operator | Aug 2024 |
| 327 | Amble Petroleum Co., Inc. | Tuscola, TX 79562 | Oil Operator | Aug 2024 |
| 328 | Ambrit Energy Corporation | Garland, TX 75044 | Oil & Gas Operator | Jun 2003 |
| 329 | Amcon Resources, Inc. | Oklahoma City, OK 73101 | Gas Operator | Jun 2016 |
| 330 | Amedan Resources, Inc. | Chickasha, OK 73023 | Oil & Gas Operator | Mar 2008 |
| 331 | Amelia Exploration LLC | Rowlett, TX 75088 | Oil Operator | Aug 2024 |
| 332 | Amen Oil LLC | Graham, TX 76450 | Oil & Gas Operator | Aug 2024 |
| 333 | Amend Energy Company | Houston, TX 77227 | Oil & Gas Operator | Apr 2002 |
| 334 | Amerac Energy Corporation | Tulsa, OK 74136 | Oil & Gas Operator | Jun 2013 |
| 335 | Amerada Hess Corporation | Houston, TX 77252 | Oil & Gas Operator | Aug 2013 |
| 336 | Ameredev Operating, LLC | Austin, TX 78746 | Oil & Gas Operator | Aug 2024 |
| 337 | American Cascade Energy, Inc. | Barker, TX 77413 | Oil & Gas Operator | Aug 2024 |
| 338 | American Coastal Energy, Inc. | Houston, TX 77225 | Oil & Gas Operator | May 2008 |
| 339 | American Cometra, Inc. | Fort Worth, TX 76102 | Oil & Gas Operator | Mar 2008 |
| 340 | American Crude, Inc. | Houston, TX 77002 | Gas Operator | Jan 1987 |
| 341 | American Delta Corporation | Portland, TX 78374 | Oil & Gas Operator | Jun 2013 |
| 342 | American Eagle Operating LLC | Gainesville, TX 76240 | Oil Operator | Aug 2024 |
| 343 | American Eagle Operating, Inc. | Spring, TX 77386 | Oil Operator | Aug 2010 |
| 344 | American Eagle Resources, Inc. | San Antonio, TX 78217 | Oil & Gas Operator | Aug 2024 |
| 345 | American Energy | Abilene, TX 79604 | Oil & Gas Operator | Jul 2004 |
| 346 | American Energy Op. Corp.,The | Houston, TX 77099 | Oil & Gas Operator | Aug 2024 |
| 347 | American Energy Partners Inc | Boerne, TX 78006 | Oil & Gas Operator | Dec 2011 |
| 348 | American Energy Sources, Inc. | Spring, TX 77388 | Oil & Gas Operator | Dec 2008 |
| 349 | American Energy Texas Inc | Mineral Wells, TX 76067 | Oil Operator | Aug 2024 |
| 350 | American Energy-Perm Basin, LLC | Oklahoma City, OK 73113 | Oil & Gas Operator | May 2016 |
| 351 | American Exploration | Houston, TX 77010 | Gas Operator | Apr 1994 |
| 352 | American Exploration Company | Houston, TX 77010 | Oil & Gas Operator | Jan 2000 |
| 353 | American Explorer, Inc. | Lafayette, LA 70505 | Oil & Gas Operator | Jan 1999 |
| 354 | American Int'L Energy Corp. | Houston, TX 77057 | Oil & Gas Operator | Aug 2019 |
| 355 | American National Petroleum Co. | Houston, TX 77057 | Oil & Gas Operator | Aug 1995 |
| 356 | American Natural Energy Corp | Oklahoma City, OK 73114 | Oil & Gas Operator | May 2023 |
| 357 | American Oilfield Systems, Inc. | Nichols Hill, OK 73116 | Oil & Gas Operator | Jun 2001 |
| 358 | American Operating Company | Kilgore, TX 75663 | Oil & Gas Operator | Oct 2003 |
| 359 | American Operating Company (A) | Dallas, TX 75244 | Oil & Gas Operator | Aug 2024 |
| 360 | American Petrofina Co Of TX | Dallas, TX 75221-2159 | Oil & Gas Operator | Nov 2000 |
| 361 | American Petroleum Corp | Addison, TX 75001 | Oil & Gas Operator | Aug 2024 |
| 362 | American Pumping & Trucking | New Braunfels, TX 78131 | Oil & Gas Operator | Aug 2024 |
| 363 | American Quasar Petroleum Co. | Fort Worth, TX 76102 | Oil & Gas Operator | Apr 2014 |
| 364 | American Resources, Inc. | Houston, TX 77079 | Oil & Gas Operator | Aug 2024 |
| 365 | American Royalty | Caldwell, TX 77836 | Oil & Gas Operator | Oct 2005 |
| 366 | American Shoreline, Inc. | Corpus Chrsti, TX 78401 | Oil & Gas Operator | Aug 2024 |
| 367 | American Star Energy & Min. Corp | Katy, TX 77449 | Oil & Gas Operator | Aug 2024 |
| 368 | American West | Burkett, TX 76828 | Oil & Gas Operator | Aug 2024 |
| 369 | American West Resources, Inc | Fort Worth, TX 76161 | Oil & Gas Operator | Aug 2024 |
| 370 | Americana Petroleum Corp | Waco, TX 76710 | Oil Operator | Aug 1992 |
| 371 | Americo Energy Resources, LLC | Houston, TX 77063 | Oil & Gas Operator | Aug 2024 |
| 372 | Americo Oil Company | Oklahoma City, OK 73154 | Oil & Gas Operator | Feb 2012 |
| 373 | Amerind Oil Company, LTD. | Midland, TX 79701 | Oil & Gas Operator | Nov 2004 |
| 374 | Ameristate Exploration LLC | Austin, TX 78701 | Oil & Gas Operator | Nov 2009 |
| 375 | Ameritech Oil & Gas Corporation | Dallas, TX 75248 | Oil & Gas Operator | May 1996 |
| 376 | Amerril Energy LLC | Houston, TX 77042 | Oil & Gas Operator | Aug 2024 |
| 377 | Ames Financial, Inc | Shreveport, LA 71101 | Oil & Gas Operator | Jun 2024 |
| 378 | Ames Oil | Cross Plains, TX 76443 | Oil & Gas Operator | Aug 2024 |
| 379 | Ames Oil Corporation Of Texas | Austin, TX 78720 | Oil & Gas Operator | Mar 2015 |
| 380 | Amexco, LLC | San Antonio, TX 78259 | Oil & Gas Operator | Aug 2024 |
| 381 | Amherst Energy Holdings, LLC | Highland VLG, TX 75077 | Oil Operator | Aug 2024 |
| 382 | Aminex USA, Inc. | Somerset, TX 78069 | Oil & Gas Operator | May 2018 |
| 383 | Amirmex Inc. | Denver, CO 80234 | Oil & Gas Operator | Aug 2024 |
| 384 | Amistad Energy Services, LLC | Katy, TX 77450 | Oil & Gas Operator | Oct 2017 |
| 385 | Amity Oil Co., Inc. | Dallas, TX 75206 | Oil & Gas Operator | Aug 1977 |
| 386 | Ammonite Energy Texas, Inc. | Midland, TX 79710 | Oil & Gas Operator | Aug 2003 |
| 387 | Amoco Production Co-Ratliff City | Ratliff City, OK 73081 | Oil Operator | May 1998 |
| 388 | Amoco Production Co. | Houston, TX 77253 | Oil & Gas Operator | Jun 2015 |
| 389 | Ampak Oil Company | Plano, TX 75074 | Oil & Gas Operator | Aug 2024 |
| 390 | Amplify Energy Operating LLC | Houston, TX 77002 | Oil & Gas Operator | Aug 2024 |
| 391 | Amron Petroleum, Inc. | Midland, TX 79708 | Oil & Gas Operator | Jan 1996 |
| 392 | Amt Resources, Inc. | Cisco, TX 76437 | Oil & Gas Operator | Aug 2024 |
| 393 | Amtex Energy | Midland, TX 79702 | Oil & Gas Operator | Aug 1995 |
| 394 | Amtex Energy, Inc. | Fort Worth, TX 76147 | Oil & Gas Operator | Aug 2024 |
| 395 | Amx Energy, Inc. | Tyler, TX 75701 | Oil & Gas Operator | Aug 2024 |
| 396 | Anadarko Austin Chalk Company | Houston, TX 77251 | Oil & Gas Operator | Feb 2006 |
| 397 | Anadarko E&P Company LP | Houston, TX 77251 | Oil & Gas Operator | Aug 2014 |
| 398 | Anadarko E&P Onshore LLC | Houston, TX 77046 | Oil & Gas Operator | Aug 2024 |
| 399 | Anadarko Minerals Inc | Oklahoma City, OK 73102 | Oil & Gas Operator | Jun 2024 |
| 400 | Anadarko Ogc Company | Houston, TX 77251 | Oil & Gas Operator | Dec 1998 |