| 401 | Belco Development Corporation | Tulsa, OK 74136 | Oil & Gas Operator | Feb 1994 |
| 402 | Belco Energy Corp. | Dallas, TX 75231 | Oil & Gas Operator | Mar 2015 |
| 403 | Belco Operating Corp. | Dallas, TX 75231 | Oil & Gas Operator | Aug 1998 |
| 404 | Belco Petroleum Corp | Grand Junction, CO | Oil & Gas Operator | Dec 1983 |
| 405 | Belden & Blake Corporation | North Canton, OH 44720 | Oil & Gas Operator | Dec 2016 |
| 406 | Belle Exploration, Inc. | | Oil & Gas Operator | Jun 2021 |
| 407 | Belle Oil, Inc. | | Oil & Gas Operator | Dec 2025 |
| 408 | Bellwether Exploration Company | Houston, TX 77010 | Oil & Gas Operator | May 2001 |
| 409 | Belnorth Petroleum Corporation | Midland, TX 79701 | Oil & Gas Operator | Feb 1991 |
| 410 | Ben Carroll | | Oil Operator | Dec 1985 |
| 411 | Bengal Oil & Gas, Inc. | | Gas Operator | Mar 2006 |
| 412 | Benton Oil & Gas Company Of La | | Oil & Gas Operator | Apr 1997 |
| 413 | Bepco, L.P. | Fort Worth, TX 76102 | Oil & Gas Operator | Dec 2008 |
| 414 | Bering Operating Company, Inc. | Tyler, TX 75701 | Oil & Gas Operator | May 2001 |
| 415 | Berkshire Operating, LLC | Kilgore, TX 75663 | Oil & Gas Operator | Feb 2026 |
| 416 | Bert & Glen Loe | | Oil Operator | Jul 1979 |
| 417 | Bert Fields, Jr. | | Oil & Gas Operator | Nov 1986 |
| 418 | Beta Oil Inc | | Oil Operator | Feb 1986 |
| 419 | Beta Operating, Inc | | Oil & Gas Operator | May 2001 |
| 420 | Bethlan Production Corporation | | Oil & Gas Operator | Dec 1994 |
| 421 | Betsy Production Company, Inc. | Magnolia, AR 71753 | Oil & Gas Operator | Dec 2025 |
| 422 | Beusa Energy, Inc. | Spring, TX 77380 | Oil & Gas Operator | Apr 2011 |
| 423 | Beusa Energy, LLC | | Oil & Gas Operator | Nov 2017 |
| 424 | Bev Exploration, Inc. | | Oil Operator | Jun 1985 |
| 425 | BHB Oil, Inc | | Oil & Gas Operator | Dec 2024 |
| 426 | BHP Billiton Petro (KCS Resources), LLC | | Oil & Gas Operator | Jul 2019 |
| 427 | BHP Billiton Petro (Txla Operating) Co. | | Gas Operator | Jul 2019 |
| 428 | BHP Billiton Petro (WSF Operating), Inc. | | Oil & Gas Operator | Jul 2019 |
| 429 | BHP Petroleum (Americas) Inc | Houston, TX 77056 | Oil & Gas Operator | Mar 2015 |
| 430 | BHP Petroleum Company Inc | Houston, TX 77057 | Oil & Gas Operator | Jun 2016 |
| 431 | BHP Petroleum, Inc. | | Oil & Gas Operator | Aug 1985 |
| 432 | Biedenharn Et Al | | Gas Operator | Nov 1996 |
| 433 | Big Creek Operating, Inc. | | Oil & Gas Operator | Jan 1991 |
| 434 | Big G Exploration, Inc. | | Oil Operator | Mar 1988 |
| 435 | Big Island Operating Corp. | | Oil & Gas Operator | Aug 1988 |
| 436 | Big M Oil Company | | Oil & Gas Operator | Jan 2025 |
| 437 | Big Pine Petroleum Inc. | | Oil & Gas Operator | Dec 2024 |
| 438 | Big River Oil Field Services, LLC | | Oil Operator | Mar 2017 |
| 439 | Big Run Production Company | Kilgore, TX 75663 | Oil & Gas Operator | Feb 2026 |
| 440 | Big-Joe Operating, Co. | | Oil & Gas Operator | May 2017 |
| 441 | Bigfoot Energy Services LLC | Carthage, TX 75633 | Oil & Gas Operator | Aug 2024 |
| 442 | Biggs Resources, Inc. | | Oil Operator | Apr 1984 |
| 443 | Biglane Operating Company | | Oil & Gas Operator | Nov 2025 |
| 444 | Bike Oil & Gas Company, Inc. | | Oil & Gas Operator | Aug 2002 |
| 445 | Bileta Corporation | | Oil & Gas Operator | Aug 2010 |
| 446 | Bill Foster | | Oil Operator | Dec 2024 |
| 447 | Bill Gary | | Gas Operator | Jul 1995 |
| 448 | Bill Gary, Et Al | | Gas Operator | Jul 1995 |
| 449 | Bill Tarver | | Oil Operator | Nov 2004 |
| 450 | Billingsley Engineering Co. | | Oil & Gas Operator | May 1994 |
| 451 | Billy A. Poisso | | Oil & Gas Operator | Apr 2023 |
| 452 | Billy E. Bayles | | Oil & Gas Operator | Apr 1998 |
| 453 | Billy P. Bullock-Production | | Oil Operator | Jan 1991 |
| 454 | Billy Young | | Oil Operator | Aug 1989 |
| 455 | Bintliff Props. LTD. PRTNRSHP. | | Oil & Gas Operator | Dec 1987 |
| 456 | Bishop Petroleum Inc. | Houston, TX 77007 | Oil & Gas Operator | Feb 2026 |
| 457 | Bison Energy Partners, LLC | | Oil & Gas Operator | Jan 2025 |
| 458 | BJT Properties Of Lasalle, LLC | | Oil Operator | Dec 2024 |
| 459 | Bke-A, L L C | | Oil & Gas Operator | Jun 1999 |
| 460 | Bke-Theall, LLC | | Oil & Gas Operator | Feb 2000 |
| 461 | BKV Ventures, LLC | | Oil & Gas Operator | Nov 2020 |
| 462 | Black Bayou Gas Processing, Inc. | | Oil Operator | Dec 2024 |
| 463 | Black Bayou Gas Systems, Inc. | | Oil Operator | Feb 2009 |
| 464 | Black Bayou Management Co Inc. | | Oil & Gas Operator | Aug 1980 |
| 465 | Black Bayou Operating, LLC | Fort Worth, TX 76116 | Oil & Gas Operator | Jan 2025 |
| 466 | Black Bayou Petroleum | | Oil Operator | Jul 1999 |
| 467 | Black Bayou Resources, Inc. | | Oil & Gas Operator | Jun 1992 |
| 468 | Black Bear Midstream LLC | | Oil Operator | Jan 2025 |
| 469 | Black Diamond Energy, LLC | | Oil & Gas Operator | Oct 2008 |
| 470 | Black Diamond Production Co. | | Oil & Gas Operator | Mar 2021 |
| 471 | Black Elk Energy Offshore Operations LLC | | Oil & Gas Operator | Jun 2016 |
| 472 | Black Gold Prod Co., Inc. | | Oil & Gas Operator | Feb 1998 |
| 473 | Black Gold Resources LLC | Houston, TX 77056 | Oil Operator | Sep 2013 |
| 474 | Black Hawk Resources | | Oil & Gas Operator | Dec 1984 |
| 475 | Black Jack Oil Co Inc | Holliday, TX 76366 | Oil & Gas Operator | Dec 2025 |
| 476 | Black Pearl Exploration, L.L.C. | Houston, TX 77095 | Oil & Gas Operator | May 2015 |
| 477 | Black Pool Energy, LP | Houston, TX 77070 | Oil & Gas Operator | Jul 2024 |
| 478 | Black Stone Oil Company | Dallas, TX 75244 | Oil & Gas Operator | Feb 1997 |
| 479 | Blackbeard Operating East LLC | Midland, TX 79701-4532 | Oil & Gas Operator | Dec 2020 |
| 480 | Blackbird Company | Shreveport, LA 71106 | Oil & Gas Operator | Jan 2025 |
| 481 | Blackbrush O & G, LLC | San Antonio, TX 78259 | Oil & Gas Operator | Feb 2026 |
| 482 | Blackhorse Energy, LLC Of Texas | | Oil Operator | Jan 2025 |
| 483 | Blackjack Oil, Inc. | Las Vegas, NV 89128 | Oil & Gas Operator | Nov 2019 |
| 484 | Blackjack Operating L. L. C. | Cibolo, TX 78108 | Oil & Gas Operator | Feb 2026 |
| 485 | Blakely Land & Exploration Co. | | Oil & Gas Operator | Apr 1991 |
| 486 | Blanco Oil Co. | San Antonio, TX 78230 | Oil & Gas Operator | Feb 2004 |
| 487 | Blanco Oil Co., Etal | | Oil Operator | Aug 1985 |
| 488 | Bligh Petroleum, Inc. | | Oil & Gas Operator | Jun 2004 |
| 489 | Block "T" Petroleum, Inc. | Tyler, TX 75707 | Oil & Gas Operator | Feb 2026 |
| 490 | Block T Operating, LLC | Dallas, TX 75201 | Oil & Gas Operator | Dec 2025 |
| 491 | Blocker Exploration Company | | Oil & Gas Operator | Apr 1983 |
| 492 | Blue Bird Oil & Gas Prod. Co. | | Gas Operator | Dec 2007 |
| 493 | Blue Creek Resources, Inc. | | Oil & Gas Operator | May 1990 |
| 494 | Blue Diamond Drilling, Inc. | | Oil Operator | Nov 1995 |
| 495 | Blue Dome Operating, LLC | Tulsa, OK 74119 | Gas Operator | Feb 2026 |
| 496 | Blue Mill Farms, Inc. | | Oil & Gas Operator | Apr 1992 |
| 497 | Blue Ridge Group, Inc. | Bowling Green, KY 42101 | Oil & Gas Operator | Dec 2023 |
| 498 | BMR Oil & Gas, Inc. | | Oil & Gas Operator | Dec 2024 |
| 499 | Bo Luvan | | Oil & Gas Operator | Oct 2003 |
| 500 | Boarich Petroleum Corporation | | Gas Operator | Mar 1996 |