| 301 | Adparo LLC | Oklahoma City, OK 73102-4803 | Oil & Gas Operator | Dec 2025 |
| 302 | Adr Operating, Inc. | Independence, KS 67301 | Oil & Gas Operator | Sep 2013 |
| 303 | Adrian Beachel | Henryetta, OK 74437 | Oil & Gas Operator | Nov 2025 |
| 304 | Ads | Caldwell, TX 77836 | Oil & Gas Operator | Dec 2010 |
| 305 | Ads Oil & Gas, Inc. | Caldwell, TX 77836 | Oil & Gas Operator | Feb 2026 |
| 306 | Advance Energy Partners Hat Mesa, LLC | Dallas, TX 75240 | Oil & Gas Operator | Jul 2023 |
| 307 | Advance Exploration | Abilene, TX 79601 | Oil & Gas Operator | Feb 2026 |
| 308 | Advance Oil Corporation | Kiefer, OK 74041-4105 | Oil & Gas Operator | Dec 2025 |
| 309 | Advanced Petro Corp | Hamburg, NY 14075-5003 | Oil & Gas Operator | Dec 1992 |
| 310 | Advanced Petroleum Enhancement, Inc | Madisonville, KY 42431 | Oil & Gas Operator | Dec 2021 |
| 311 | Advanced Recovery Services Co | Denver, CO 80265 | Oil & Gas Operator | Apr 2007 |
| 312 | Advanced Wireless Communications, L.L.C. | Farmington, NM 87401 | Oil & Gas Operator | Jan 2026 |
| 313 | Advantage Oil & Gas, Inc. | Pinehurst, TX 77362 | Oil & Gas Operator | Feb 2026 |
| 314 | Advantage Resour | | Oil & Gas Operator | May 1994 |
| 315 | Advantage Resources Inc | Broomfield, CO 80020 | Oil & Gas Operator | Sep 2025 |
| 316 | Advantagewon Oil, Us, Corp. | Batson, TX 77519 | Oil Operator | Dec 2019 |
| 317 | Advent Oil & Operating Inc | Gulfport, MS 39506-7115 | Oil & Gas Operator | Nov 2014 |
| 318 | Adventure Expl Partners II, LLC | Midland, TX 79701 | Oil & Gas Operator | Oct 2014 |
| 319 | Adventure Exploration Partners, LLC | Midland, TX 79702 | Oil & Gas Operator | Oct 2011 |
| 320 | Adventure Exploration PTRS, LLC | Midland, TX 79702 | Oil & Gas Operator | Aug 2012 |
| 321 | Adventure Operating Company, LLC | Midland, TX 79702 | Oil & Gas Operator | Jan 2021 |
| 322 | Adventure Properties Inc | Ada, OK 74820 | Oil & Gas Operator | Nov 2025 |
| 323 | Aec Operating Company | Roswell, NM 88202 | Oil & Gas Operator | Sep 2006 |
| 324 | Aed Development Inc | Columbus, OH 43220 | Oil & Gas Operator | Dec 1995 |
| 325 | Aeg Operating, LLC | Austin, TX 78746 | Oil Operator | Jun 2012 |
| 326 | Aegean Oil & Gas Inc | Brunswick, OH 44212 | Oil & Gas Operator | Dec 1993 |
| 327 | Aegean Petroleum | | Oil Operator | Mar 1982 |
| 328 | Aegis Energy, Inc. | Lafayette, LA 70505 | Oil & Gas Operator | Sep 1998 |
| 329 | Aegis Fluids Management, LLC | Plano, TX 75093 | Oil & Gas Operator | Feb 2026 |
| 330 | Aei Corporation-Oklahoma | Oklahoma City, OK 73101-1945 | Oil & Gas Operator | Sep 2014 |
| 331 | Aei Production Company | Edmond, OK 73083 | Oil & Gas Operator | Mar 2014 |
| 332 | Aeon Energy Corp. | | Oil & Gas Operator | Jan 2026 |
| 333 | Aeon Energy Inc | Claremore, OK 74017 | Oil Operator | May 2009 |
| 334 | Aeon Operating, Inc. | Fate, TX 75132 | Oil & Gas Operator | Feb 2026 |
| 335 | Aera Energy LLC | | Oil & Gas Operator | Dec 2025 |
| 336 | Aerie Energy | Cedar Creek, TX 78612 | Oil Operator | Feb 2026 |
| 337 | Aesir Energy | | Oil Operator | Oct 2007 |
| 338 | Aeternum Energy, LLC | Tyler, TX 75713 | Oil & Gas Operator | Feb 2026 |
| 339 | Aethon Energy Operating LLC | Dallas, TX 75251 | Oil & Gas Operator | Feb 2026 |
| 340 | Aethon I LP | Dallas, TX 75206 | Oil & Gas Operator | Mar 2015 |
| 341 | Aexco Petroleum Inc | Denver, CO 80202 | Oil & Gas Operator | Dec 2025 |
| 342 | Af Operating, LLC | Tuscaloosa, AL 35404 | Oil Operator | Sep 2012 |
| 343 | Afco Energy Prod Co | Indiana, PA 15701-0538 | Oil & Gas Operator | Dec 2019 |
| 344 | Afe Management Limited | Concord, Ontario, L4K 4G4 | Oil & Gas Operator | Sep 1987 |
| 345 | Afe Oil & Gas Consultants | Addison, TX 75001 | Gas Operator | Jan 2003 |
| 346 | Affiliated Holdings, Inc. | | Oil Operator | Dec 2010 |
| 347 | Afg Energy, Inc. | Houston, TX 77002 | Oil & Gas Operator | Dec 2009 |
| 348 | Afo LLC | Velma, OK 73491 | Oil & Gas Operator | Dec 2024 |
| 349 | Afoc, LLC | Fort Worth, TX 76147 | Oil & Gas Operator | Feb 2026 |
| 350 | Agape Energy Inc. | San Antonio, TX 78280 | Oil Operator | Feb 2026 |
| 351 | Agape Inc | Broken Arrow, OK 74011-4256 | Oil & Gas Operator | Sep 2025 |
| 352 | Agape Service Incorporated | Denver, CO 80201 | Gas Operator | Sep 2025 |
| 353 | Agar & Agar Inc | Norman, OK 73070 | Oil & Gas Operator | Oct 1996 |
| 354 | Agate Petroleum, Inc. | Tulsa, OK 74119 | Oil & Gas Operator | Mar 2015 |
| 355 | Agave Energy Inc | Stigler, OK 74462 | Oil & Gas Operator | Nov 2025 |
| 356 | Agave Operating Company, Inc. | Holliday, TX 76366 | Oil Operator | Feb 2026 |
| 357 | Agent Oil Corporation | Bison, OK 73720-0116 | Oil & Gas Operator | Mar 2005 |
| 358 | Ageron Energy, LLC | San Antonio, TX 78209 | Oil & Gas Operator | Feb 2026 |
| 359 | Agey Petroleum Co. | | Oil & Gas Operator | Dec 1998 |
| 360 | Aggie Oil Company | Lakewood, CO 80226 | Oil & Gas Operator | May 2001 |
| 361 | Aggietech Oil, LTD. | Midland, TX 79701 | Oil & Gas Operator | Aug 2016 |
| 362 | Aghorn Operating, Inc. | Odessa, TX 79768 | Oil & Gas Operator | Feb 2026 |
| 363 | Agip Petroleum Co., Inc. | | Oil & Gas Operator | Jan 2003 |
| 364 | Agis Energy Inc. | Lafayette, LA 70508 | Oil & Gas Operator | Feb 2026 |
| 365 | Agis Energy LLC | Lafayette, LA 70508 | Oil & Gas Operator | Feb 2026 |
| 366 | Agp Energy Services LLC | Midland, TX 79701 | Oil & Gas Operator | Feb 2026 |
| 367 | Agri-Acres Inc | Billings, MT 59103 | Oil Operator | Jun 1996 |
| 368 | Agricultural Energy Services | Edmond, OK 73003 | Oil & Gas Operator | Sep 2025 |
| 369 | Agricultural Energy Services Inc | Edmond, OK 73012 | Oil Operator | Oct 2025 |
| 370 | Agroil, Inc. | Brownwood, TX 76801 | Oil & Gas Operator | Feb 2026 |
| 371 | Agua Sucia LLC | Lovington, NM 88260 | Oil & Gas Operator | Jul 2018 |
| 372 | Aguila Operating Company LLC | Edmond, OK 73034 | Oil & Gas Operator | Nov 2025 |
| 373 | Agv Corp. | Attica, KS 67009 | Oil & Gas Operator | Sep 2025 |
| 374 | Ah Operating, LLC | Midland, TX 79710 | Gas Operator | Feb 2026 |
| 375 | Ahabb Oil | Luling, TX 78648 | Oil & Gas Operator | Dec 1998 |
| 376 | Aicr LLC | Odessa, TX 79768 | Oil Operator | Feb 2026 |
| 377 | Aiello Bros Oil & Gas Inc | Bradford, PA 16701-2925 | Oil & Gas Operator | Dec 2024 |
| 378 | Aikins Drilling Company | Mohave Valley, AZ 86440 | Oil Operator | Dec 2019 |
| 379 | Aikman Brothers | Midland, TX 79705 | Oil & Gas Operator | Dec 2000 |
| 380 | Aikman Brothers, LLC | Amarillo, TX 79109 | Oil & Gas Operator | Nov 2025 |
| 381 | Aikman Oil Corp. | Oklahoma City, OK 73157 | Oil & Gas Operator | Feb 2026 |
| 382 | Ailey A C | Stroud, OK 74079-9209 | Oil & Gas Operator | Nov 2021 |
| 383 | Aim Consultants Inc. | Rockville, MD 20852 | Oil & Gas Operator | Mar 2008 |
| 384 | Aim Energy LLC | North Canton, OH 44720 | Oil & Gas Operator | Dec 2024 |
| 385 | Ainsworth Operat | | Oil Operator | Apr 1995 |
| 386 | Ainsworth Operating Co. | Salem, OR 97302 | Oil Operator | Sep 2025 |
| 387 | Ainsworth Prod Co. | | Oil Operator | Aug 1986 |
| 388 | Ainsworth Rig Service, LLC | | Oil Operator | Nov 2024 |
| 389 | Ainsworth, Otis | | Oil & Gas Operator | Jun 1987 |
| 390 | Airdale Oil & Gas LLC | Oil City, PA 16301-3771 | Oil & Gas Operator | Dec 2025 |
| 391 | Airport Developm | | Gas Operator | Apr 1993 |
| 392 | Aix Energy Inc | | Oil & Gas Operator | Jul 2016 |
| 393 | Aix Energy LLC | | Oil & Gas Operator | Jan 2026 |
| 394 | Aj Oil, Inc. | Springfield, LA 70462 | Oil Operator | Oct 2019 |
| 395 | Aj'S Pump Truck Service, Inc. | Odessa, TX 79760 | Oil & Gas Operator | Feb 2026 |
| 396 | Ajar International, Inc. | Randolph, NY 14772 | Gas Operator | Dec 2024 |
| 397 | Ajax Oil & Gas C | | Oil & Gas Operator | Jun 1989 |
| 398 | Ajax Oil Company | Billings, MT 59103 | Oil & Gas Operator | Dec 2003 |
| 399 | Ajax Resources, LLC | Houston, TX 77046 | Oil & Gas Operator | Feb 2026 |
| 400 | Ajb Oil LLC | Tulsa, OK 74114-5218 | Oil Operator | Nov 2025 |