| 501 | Bois D'Arc Offshore LTD. | Houston, TX 77002 | Oil & Gas Operator | Aug 2008 |
| 502 | Bois D'Arc Operating Corporation | Houston, TX 77040 | Oil & Gas Operator | Jan 2000 |
| 503 | Bolinger Oil L.L.C. | | Oil Operator | Dec 2024 |
| 504 | Bomar Oil & Gas, Inc. | Dallas, TX 75206 | Oil & Gas Operator | Dec 2020 |
| 505 | Bon Oil Company, Inc. | | Oil & Gas Operator | Nov 1993 |
| 506 | Bonanza Salvage & Prod. Co Inc | | Oil & Gas Operator | Oct 2005 |
| 507 | Bonita Hydrocarbons Company | Dallas, TX 75229 | Oil & Gas Operator | Jun 2008 |
| 508 | Bonner & Carter | | Oil & Gas Operator | Sep 1988 |
| 509 | Booher Energy, LLC | | Oil Operator | Dec 2024 |
| 510 | Booher Engineering, Inc. | Tyler, TX 75711 | Oil & Gas Operator | May 2025 |
| 511 | Bopco, L.P. | Midland, TX 79701 | Oil & Gas Operator | May 2025 |
| 512 | Borden, Inc. | Columbus, OH 43215 | Oil & Gas Operator | May 1990 |
| 513 | Bottomland Energy, LLC | | Oil Operator | Dec 2024 |
| 514 | Bowie Operating Company, LLC | Graham, TX 76450 | Oil & Gas Operator | Mar 2011 |
| 515 | Boyter Brothers | | Oil Operator | Jul 1995 |
| 516 | BP America Production Company | Denver, CO 80202 | Oil & Gas Operator | Feb 2025 |
| 517 | BP Exploration Inc | | Oil & Gas Operator | May 1993 |
| 518 | BPR Energy, Inc. | | Oil & Gas Operator | Apr 2021 |
| 519 | BPX (KCS Resources), LLC | | Oil & Gas Operator | Feb 2022 |
| 520 | BPX Operating Company | Denver, CO 80202 | Oil & Gas Operator | May 2025 |
| 521 | Brad Acree Pet. Consultants | | Oil & Gas Operator | Apr 1986 |
| 522 | Bradco Oil & Gas Company | | Oil & Gas Operator | Dec 1980 |
| 523 | Bradford Oil Company | Denver, CO 80249 | Oil & Gas Operator | Apr 2025 |
| 524 | Bradford Oil LLC | | Oil Operator | Jan 2025 |
| 525 | Bradoil, Inc. | | Gas Operator | Feb 1991 |
| 526 | Bralorne International, Inc. | | Oil Operator | Jan 1987 |
| 527 | Brammer Engineering, Inc. | Shreveport, LA 71101 | Oil & Gas Operator | May 2025 |
| 528 | Brammer Petroleum, Inc. | Gainesville, TX 76241 | Oil & Gas Operator | May 2025 |
| 529 | Brammer-Keystone Energy, L.L.C. | Shreveport, LA 71101 | Oil & Gas Operator | Mar 2000 |
| 530 | Branch Investment Corporation | | Oil & Gas Operator | Jan 2025 |
| 531 | Branta Production Company LLC | The Woodlands, TX 77380 | Oil & Gas Operator | May 2025 |
| 532 | Brasseaux Oil Company | Wichita Falls, TX 76309 | Oil & Gas Operator | Mar 2008 |
| 533 | Bray Drilling Co., Inc. | | Oil Operator | Feb 1982 |
| 534 | Brazos River LLC | | Oil & Gas Operator | Apr 2002 |
| 535 | Brbco, LLC | | Oil & Gas Operator | Dec 2024 |
| 536 | Breakthrough Ventures, LLC | | Oil Operator | Jan 2025 |
| 537 | Brechtel Energy Corporation | | Oil & Gas Operator | Sep 2008 |
| 538 | Breck Operating Corp. | Breckenridge, TX 76424 | Oil & Gas Operator | Feb 2025 |
| 539 | Brehm Exploration, Inc. | | Oil & Gas Operator | Mar 1995 |
| 540 | Breitburn Operating LP | Houston, TX 77002 | Oil & Gas Operator | May 2025 |
| 541 | Brent Exploration Inc. | | Oil & Gas Operator | Apr 1983 |
| 542 | Breton Sound Holdings, LLC | | Oil & Gas Operator | Dec 2024 |
| 543 | Brewton And Martin | | Oil Operator | Dec 1997 |
| 544 | BRG Petroleum Corporation | Tulsa, OK 74136 | Oil & Gas Operator | Mar 2020 |
| 545 | Brian C. Register | | Oil & Gas Operator | Jun 2011 |
| 546 | Bridas Energy USA, Inc. | The Woodlands, TX 77380 | Oil & Gas Operator | Aug 2008 |
| 547 | Bridge Oil Company LP | Midland, TX 79702 | Oil & Gas Operator | May 1999 |
| 548 | Bridges Drilling | | Oil & Gas Operator | Jan 2025 |
| 549 | Bridges Oil Co Etal | | Oil Operator | Dec 1996 |
| 550 | Bridwell Oil Company | Wichita Falls, TX 76307 | Oil & Gas Operator | May 2025 |
| 551 | Bridwell Oil Management, LLC | Wichita Falls, TX 76307 | Oil & Gas Operator | May 2025 |
| 552 | Bridwell Oil MGMT Of Al, LLC | | Oil & Gas Operator | Apr 2006 |
| 553 | Briggs Operating Company | | Oil & Gas Operator | Nov 1998 |
| 554 | Briggs Properties, L.L.C. | | Oil Operator | Mar 2015 |
| 555 | Brigham Oil & Gas, L.P. | Austin, TX 78730 | Oil & Gas Operator | Oct 2015 |
| 556 | Bright & Company | The Colony, TX 75056 | Oil & Gas Operator | May 2015 |
| 557 | Bright & Schiff | | Oil & Gas Operator | Dec 1977 |
| 558 | Brighton Energy LLC | Tulsa, OK 74170 | Oil & Gas Operator | Mar 2015 |
| 559 | Bristol Resources Corporation | Tulsa, OK 74170 | Oil & Gas Operator | Feb 2022 |
| 560 | British-Borneo Exploration Inc | | Oil & Gas Operator | Dec 1999 |
| 561 | Britlind Oil LLC | | Oil & Gas Operator | Dec 2020 |
| 562 | Brix Operating LLC | | Gas Operator | Apr 2021 |
| 563 | Broad Oak Energy, Inc. | Farmers BRNCH, TX 75234 | Oil & Gas Operator | Jul 2011 |
| 564 | Broad Street Financial Co. | | Oil & Gas Operator | Nov 1998 |
| 565 | Brock Energy Corporation | Houston, TX 77002 | Oil & Gas Operator | Jun 1986 |
| 566 | Brock Exploration Corporation | New Orleans, LA 70112-1707 | Oil & Gas Operator | Jan 1999 |
| 567 | Brock Oil & Gas Corporation | Tulsa, OK 74103 | Oil & Gas Operator | Jun 2019 |
| 568 | Brock Petroleum Corporation | | Oil & Gas Operator | Sep 1984 |
| 569 | Broco Oil, LP | | Oil & Gas Operator | Nov 2024 |
| 570 | Bronco Resources Inc. | | Oil Operator | Dec 1984 |
| 571 | Brooklyn Union Expl. Co., Inc. | | Oil & Gas Operator | Jul 1994 |
| 572 | Brooks And Lee | | Oil & Gas Operator | Dec 1994 |
| 573 | Brooks Oil Company | Kilgore, TX 75662 | Oil & Gas Operator | May 2025 |
| 574 | Brookston Energy, Inc. | Tyler, TX 75702 | Oil & Gas Operator | May 2025 |
| 575 | Brookwater Energy Services, LLC | | Oil & Gas Operator | Dec 2024 |
| 576 | Brown & McKenzie, Inc. | | Oil & Gas Operator | May 1984 |
| 577 | Brown Oil Properties | | Oil Operator | Nov 1983 |
| 578 | Brown Operating & MGMT Corp. | | Oil & Gas Operator | Feb 1991 |
| 579 | Browning Oil Company, Inc. | Dallas, TX 75251 | Oil & Gas Operator | May 2025 |
| 580 | Broyles Oil & Gas, Inc. | | Oil & Gas Operator | Jun 1994 |
| 581 | Broyles-Wheless Industries Inc | | Oil & Gas Operator | Apr 1993 |
| 582 | Bruce H. Weaver & Sons | | Oil Operator | Jan 2025 |
| 583 | Bruce H. Weaver Prod. | | Oil Operator | Nov 1987 |
| 584 | Bruce N. Lynn | | Oil & Gas Operator | Sep 1994 |
| 585 | Brumar, Inc. | | Oil Operator | Dec 1995 |
| 586 | Brumley Prod. | | Oil & Gas Operator | Jun 2006 |
| 587 | Brushy Creek Oil Co. | Luling, TX 78648 | Oil & Gas Operator | May 2025 |
| 588 | Bruxoil Inc | | Oil & Gas Operator | Feb 2025 |
| 589 | Bryant Oil & Gas Corporation | | Oil & Gas Operator | Mar 1987 |
| 590 | Bse Production Co. | Victoria, TX 77903 | Oil & Gas Operator | May 2025 |
| 591 | Bsfi Western E & P, Inc. | | Oil & Gas Operator | Jun 2005 |
| 592 | Bsi Operating, LLC | | Oil & Gas Operator | Dec 2019 |
| 593 | Bta Oil Producers | Midland, TX 79701 | Oil & Gas Operator | Sep 2009 |
| 594 | Bta Oil Producers, LLC | Midland, TX 79701 | Oil & Gas Operator | May 2025 |
| 595 | Buckeye Petroleum Company, Inc | | Oil & Gas Operator | Apr 1983 |
| 596 | Bud'S Pumping Service Inc. | | Oil Operator | Dec 1997 |
| 597 | Buffco Production, Inc. | Longview, TX 75606 | Oil & Gas Operator | May 2025 |
| 598 | Bull Operating, LLC | Houston, TX 77010 | Oil & Gas Operator | May 2025 |
| 599 | Burk Royalty Co., LTD. | Wichita Falls, TX 76308 | Oil & Gas Operator | May 2025 |
| 600 | Burk Royalty Company | Wichita Falls, TX 76308 | Oil & Gas Operator | Jan 2002 |