| 21501 | Otc Investors Inc | | Oil Operator | Jan 2025 |
| 21502 | Otc Petroleum Corporation | Nichols Hill, OK 73116 | Oil & Gas Operator | Mar 2015 |
| 21503 | Otc/Occ Not Assigned | | Oil & Gas Operator | Dec 2024 |
| 21504 | Otex Inc | N Canton, OH 44720 | Oil & Gas Operator | Dec 1988 |
| 21505 | Otex LLC | Santa Anna, TX 76878 | Oil & Gas Operator | May 2025 |
| 21506 | Otex Resources LLC | Baytown, TX 77520 | Oil & Gas Operator | May 2025 |
| 21507 | Otis C. Coles, Jr. | | Oil & Gas Operator | Jan 1998 |
| 21508 | Oto, Co. | Woodward, OK 73802 | Oil & Gas Operator | Jun 1998 |
| 21509 | Ott Inc | Casper, WY 82602 | Oil Operator | Dec 2024 |
| 21510 | Otter Exploration Inc | Warren, PA 16365-9689 | Oil & Gas Operator | Dec 2021 |
| 21511 | Ouachita Development Corp. | | Gas Operator | Mar 2014 |
| 21512 | Ouachita Exploration Inc | Chickasha, OK 73018 | Oil & Gas Operator | Feb 2025 |
| 21513 | Ouida Oil | Rowlett, TX 75030 | Oil & Gas Operator | Mar 2008 |
| 21514 | Ouida Oil Co. | | Oil & Gas Operator | Apr 1999 |
| 21515 | Outback Oil, Inc. | Pratt, KS 67124 | Gas Operator | Sep 2019 |
| 21516 | Outback Petroleum Inc | Moore, OK 73160-9998 | Oil & Gas Operator | Mar 2015 |
| 21517 | Outlaw Oil And Gas LLC | Kaw City, OK 74641 | Oil & Gas Operator | Feb 2025 |
| 21518 | Outlaw Oil LLC | Caldwell, TX 77836 | Oil & Gas Operator | May 2025 |
| 21519 | Outlaw Well Service LLC | Hays, KS 67601 | Oil Operator | Oct 2024 |
| 21520 | Outline Oil Company LLC | Beeville, TX 78104 | Oil Operator | May 2025 |
| 21521 | Outline Oil Corp. | San Antonio, TX 78217 | Oil & Gas Operator | May 2025 |
| 21522 | Outlook Petroleum Corp. | Midland, TX 79702 | Oil & Gas Operator | Jan 2001 |
| 21523 | Outman, Joshua J. | Andover, NY 14806 | Oil & Gas Operator | Dec 2023 |
| 21524 | Output Acquisition Corp. | | Oil & Gas Operator | Jul 2010 |
| 21525 | Output Exploration LLC | | Oil & Gas Operator | Dec 2006 |
| 21526 | Ouut Investing LLC | Mineral Wells, TX 76068 | Oil Operator | Mar 2020 |
| 21527 | Ovaco Energy Inc. | | Oil & Gas Operator | Nov 2009 |
| 21528 | Ovation Energy II, LP | Houston, TX 77279 | Oil & Gas Operator | Jun 2011 |
| 21529 | Ovation Energy, LP | N Richlnd HLS, TX 76180 | Oil & Gas Operator | Sep 2004 |
| 21530 | Overfield, Lee R | Waverly, KY 42462 | Oil Operator | Dec 2016 |
| 21531 | Overflow Energy Stack LLC | Booker, TX 79005 | Oil Operator | Sep 2022 |
| 21532 | Overflow Energy, LLC | Booker, TX 79005 | Oil & Gas Operator | May 2025 |
| 21533 | Overland Exploration Company | | Oil Operator | Jan 2025 |
| 21534 | Overland Investments Inc | Coweta, OK 74429 | Oil & Gas Operator | Feb 2025 |
| 21535 | Overland Operating Company, LLC | Abilene, TX 79601 | Oil Operator | May 2025 |
| 21536 | Overland Resources LLC | Greenwood VIllage, CO 80111 | Oil & Gas Operator | Jul 2019 |
| 21537 | Overly Operating Co. | San Antonio, TX 78209 | Oil & Gas Operator | Jul 2013 |
| 21538 | Overstreet, Jamie L | Hondo, TX 78861 | Oil & Gas Operator | May 2025 |
| 21539 | Overton Park Oil & Gas LP | Fort Worth, TX 76109 | Oil & Gas Operator | May 2025 |
| 21540 | Ovintiv Mid-Continent Inc. | The Woodlands, TX 77380-2764 | Oil & Gas Operator | Mar 2025 |
| 21541 | Ovintiv USA Inc. | Denver, CO 80202 | Oil & Gas Operator | May 2025 |
| 21542 | Owco Production Co., Inc. | | Oil Operator | Aug 1997 |
| 21543 | Owen Production Co | | Oil Operator | May 2001 |
| 21544 | Owen'S Pumping Service | | Oil Operator | Jan 2025 |
| 21545 | Owen, Matthew | Hamilton, KS 66853 | Oil Operator | Sep 2016 |
| 21546 | Owens James W | Tulsa, OK 74114-1425 | Oil & Gas Operator | Oct 2022 |
| 21547 | Owens Oil | | Oil Operator | Dec 2000 |
| 21548 | Owens Oil Company | Iowa Park, TX 76367 | Oil & Gas Operator | Sep 2008 |
| 21549 | Owens Oil Company, LLC | Yates Center, KS 66783 | Oil Operator | Jan 2025 |
| 21550 | Owens Pet Inc | Midland, TX 79702 | Oil & Gas Operator | Aug 1995 |
| 21551 | Owens Petroleum | | Oil Operator | May 2006 |
| 21552 | Owens Petroleum LLC | Yates Center, KS 66783 | Oil & Gas Operator | Jan 2025 |
| 21553 | Owens Petroleum, Inc. | Midland, TX 79702 | Oil & Gas Operator | Aug 1995 |
| 21554 | Owi Operating Co. LC | Ottawa, KS 66067 | Oil & Gas Operator | Dec 2009 |
| 21555 | Owl Creek Operating Co., Inc. | Denver, CO 80206 | Oil & Gas Operator | May 2025 |
| 21556 | Owl Creek Production Co., Inc. | Houston, TX 77027 | Oil & Gas Operator | Apr 2006 |
| 21557 | Owl Creek Production Co., LLC | Denver, CO 80265 | Oil & Gas Operator | Jan 2006 |
| 21558 | Owl Operating Ventures L.L.C. | Midland, TX 79708 | Oil & Gas Operator | Dec 2022 |
| 21559 | Owl Ops II LLC | Midland, TX 79701 | Oil & Gas Operator | May 2025 |
| 21560 | Owl Ops LLC | Midland, TX 79701 | Oil & Gas Operator | May 2025 |
| 21561 | Own Resources Operating LLC | The Woodlands, TX 77381 | Oil & Gas Operator | Mar 2025 |
| 21562 | Ows Acquisition Co LLC | Louisville, OH 44641 | Oil & Gas Operator | Dec 2024 |
| 21563 | Ows Energy LLC | Carlton, PA 16311-1605 | Oil & Gas Operator | Feb 2025 |
| 21564 | Ows Energy, Inc. | Montgomery, TX 77356 | Oil & Gas Operator | May 2025 |
| 21565 | Oxbow EP LLC | | Oil Operator | Dec 2024 |
| 21566 | Oxbow Oil Company,A Kansas General Partnership | Grenola, KS 67346 | Oil Operator | Apr 2015 |
| 21567 | Oxbow Petroleum, LLC | Midland, TX 79703 | Oil & Gas Operator | May 2025 |
| 21568 | Oxbow Properties Inc | Centennial, CO 80122-1422 | Oil & Gas Operator | Jan 2025 |
| 21569 | Oxco, LLC | | Oil & Gas Operator | Feb 2015 |
| 21570 | Oxenergy Incorporated | Flower Mound, TX 75022 | Oil & Gas Operator | May 2025 |
| 21571 | Oxford Explorati | | Oil & Gas Operator | Mar 1993 |
| 21572 | Oxford Exploration | | Oil Operator | Apr 1988 |
| 21573 | Oxford Exploration Company | Denver, CO 80237 | Oil & Gas Operator | Aug 1995 |
| 21574 | Oxford Oil | Zanesville, OH 43702-0910-0910 | Oil & Gas Operator | Dec 2012 |
| 21575 | Oxford Oil Co. | Rockdale, TX 76567 | Oil & Gas Operator | Aug 2004 |
| 21576 | Oxford Oil Inc | Cleveland, OK 74020 | Oil & Gas Operator | Feb 1997 |
| 21577 | Oxley Energy LLC | Houston, TX 77042 | Gas Operator | Feb 2025 |
| 21578 | Oxley John C | Tulsa, OK 74103 | Oil & Gas Operator | Sep 1996 |
| 21579 | Oxley Petroleum | Tulsa, OK 74119-3609 | Oil & Gas Operator | Jan 2020 |
| 21580 | Oxley Petroleum Co | Oklahoma City, OK 73118-1044 | Oil & Gas Operator | Sep 2017 |
| 21581 | Oxson Co. | Uvalde, TX 78802 | Gas Operator | May 2025 |
| 21582 | Oxtex Inc | | Oil & Gas Operator | Oct 1989 |
| 21583 | Oxxn | Weatherford, TX 76086 | Oil & Gas Operator | Oct 2023 |
| 21584 | Oxy Little Knife, LLC | | Oil & Gas Operator | Jan 2016 |
| 21585 | Oxy Petroleum Inc | | Oil & Gas Operator | Jan 1986 |
| 21586 | Oxy USA | | Oil Operator | Apr 1992 |
| 21587 | Oxy USA Inc | Houston, TX 77046 | Oil & Gas Operator | May 2025 |
| 21588 | Oxy USA WTP Limited Partnership | Houston, TX 772104294 | Oil & Gas Operator | Mar 2025 |
| 21589 | Oxy USA WTP LP | Houston, TX 77046 | Oil & Gas Operator | May 2025 |
| 21590 | Oxyrock Operating, LLC | Houston, TX 77046 | Oil & Gas Operator | May 2025 |
| 21591 | Oz Gas Corporation | Austin, TX 78746 | Gas Operator | May 2025 |
| 21592 | Oz Gas LTD | Tidioute, PA 16351-2648 | Oil & Gas Operator | Dec 2016 |
| 21593 | Ozark Enterprise | | Oil Operator | Nov 1990 |
| 21594 | Ozark Exploration, Inc. | Dallas, TX 75205 | Oil & Gas Operator | May 2025 |
| 21595 | Ozark Oil Corporation | Springfield, MO 65804 | Oil & Gas Operator | Oct 1992 |
| 21596 | Ozark Oil LLC | Beallsville, OH 43716 | Oil & Gas Operator | Dec 2024 |
| 21597 | Ozark Production Company, Inc. | | Oil & Gas Operator | Jan 2025 |
| 21598 | Oztx Oil & Gas, L.L.C. | Ozona, TX 76943 | Oil & Gas Operator | May 2025 |
| 21599 | Ozzo Corporation, The | Bedford, TX 76021 | Oil Operator | May 2025 |
| 21600 | P & A Oilfield Services, Inc. | | Oil & Gas Operator | Jan 1998 |