| 21401 | Outlook Petroleum Corp. | Midland, TX 79702 | Oil & Gas Operator | Jan 2001 |
| 21402 | Outman, Joshua J. | Andover, NY 14806 | Oil & Gas Operator | Dec 2024 |
| 21403 | Output Acquisition Corp. | | Oil & Gas Operator | Jul 2010 |
| 21404 | Output Exploration LLC | | Oil & Gas Operator | Dec 2006 |
| 21405 | Ouut Investing LLC | Mineral Wells, TX 76068 | Oil Operator | Mar 2020 |
| 21406 | Ovaco Energy Inc. | | Oil & Gas Operator | Nov 2009 |
| 21407 | Ovation Energy II, LP | Houston, TX 77279 | Oil & Gas Operator | Jun 2011 |
| 21408 | Ovation Energy, LP | N Richlnd HLS, TX 76180 | Oil & Gas Operator | Sep 2004 |
| 21409 | Overfield, Lee R | Waverly, KY 42462 | Oil Operator | Dec 2016 |
| 21410 | Overflow Energy Stack LLC | Booker, TX 79005 | Oil Operator | Sep 2022 |
| 21411 | Overflow Energy, LLC | Perryton, TX 79070 | Oil & Gas Operator | Oct 2025 |
| 21412 | Overland Exploration Company | | Oil Operator | May 2025 |
| 21413 | Overland Investments Inc | Coweta, OK 74429 | Oil & Gas Operator | Jun 2025 |
| 21414 | Overland Operating Company, LLC | Abilene, TX 79601 | Oil Operator | Oct 2025 |
| 21415 | Overland Resources LLC | Greenwood VIllage, CO 80111 | Oil & Gas Operator | Jul 2019 |
| 21416 | Overly Operating Co. | San Antonio, TX 78209 | Oil & Gas Operator | Jul 2013 |
| 21417 | Overstreet, Jamie L | Hondo, TX 78861 | Oil & Gas Operator | Oct 2025 |
| 21418 | Overton Park Oil & Gas LP | Fort Worth, TX 76109 | Oil & Gas Operator | Oct 2025 |
| 21419 | Ovintiv Mid-Continent Inc. | The Woodlands, TX 77380-2764 | Oil & Gas Operator | Jun 2025 |
| 21420 | Ovintiv USA Inc. | Denver, CO 80202 | Oil & Gas Operator | Oct 2025 |
| 21421 | Owco Production Co., Inc. | | Oil Operator | Aug 1997 |
| 21422 | Owen Production Co | | Oil Operator | May 2001 |
| 21423 | Owen'S Pumping Service | | Oil Operator | Jun 2025 |
| 21424 | Owen, Matthew | Hamilton, KS 66853 | Oil Operator | Sep 2016 |
| 21425 | Owens James W | Tulsa, OK 74114-1425 | Oil & Gas Operator | Oct 2022 |
| 21426 | Owens Oil | | Oil Operator | Dec 2000 |
| 21427 | Owens Oil Company | Iowa Park, TX 76367 | Oil & Gas Operator | Sep 2008 |
| 21428 | Owens Oil Company, LLC | Yates Center, KS 66783 | Oil Operator | Jun 2025 |
| 21429 | Owens Pet Inc | Midland, TX 79702 | Oil & Gas Operator | Aug 1995 |
| 21430 | Owens Petroleum | | Oil Operator | May 2006 |
| 21431 | Owens Petroleum LLC | Yates Center, KS 66783 | Oil & Gas Operator | Jun 2025 |
| 21432 | Owens Petroleum, Inc. | Midland, TX 79702 | Oil & Gas Operator | Aug 1995 |
| 21433 | Owi Operating Co. LC | Ottawa, KS 66067 | Oil & Gas Operator | Dec 2009 |
| 21434 | Owl Creek Operating Co., Inc. | Denver, CO 80206 | Oil & Gas Operator | Oct 2025 |
| 21435 | Owl Creek Production Co., Inc. | Houston, TX 77027 | Oil & Gas Operator | Apr 2006 |
| 21436 | Owl Creek Production Co., LLC | Denver, CO 80265 | Oil & Gas Operator | Jan 2006 |
| 21437 | Owl Operating Ventures L.L.C. | Midland, TX 79708 | Oil & Gas Operator | Dec 2022 |
| 21438 | Owl Ops II LLC | Midland, TX 79701 | Oil & Gas Operator | Oct 2025 |
| 21439 | Owl Ops LLC | Midland, TX 79701 | Oil & Gas Operator | Oct 2025 |
| 21440 | Own Resources Operating LLC | The Woodlands, TX 77381 | Oil & Gas Operator | Jul 2025 |
| 21441 | Ows Acquisition Co LLC | Louisville, OH 44641 | Oil & Gas Operator | Dec 2024 |
| 21442 | Ows Energy LLC | Carlton, PA 16311-1605 | Oil & Gas Operator | Jul 2025 |
| 21443 | Ows Energy, Inc. | Montgomery, TX 77356 | Oil & Gas Operator | Oct 2025 |
| 21444 | Oxbow EP LLC | Mathis, TX 78368 | Oil Operator | Oct 2025 |
| 21445 | Oxbow Oil Company,A Kansas General Partnership | Grenola, KS 67346 | Oil Operator | Apr 2015 |
| 21446 | Oxbow Petroleum, LLC | Midland, TX 79703 | Oil & Gas Operator | May 2025 |
| 21447 | Oxbow Properties Inc | Centennial, CO 80122-1422 | Oil & Gas Operator | Jan 2025 |
| 21448 | Oxco, LLC | | Oil & Gas Operator | Feb 2015 |
| 21449 | Oxenergy Incorporated | Flower Mound, TX 75022 | Oil & Gas Operator | Oct 2025 |
| 21450 | Oxford Explorati | | Oil & Gas Operator | Mar 1993 |
| 21451 | Oxford Exploration | | Oil Operator | Apr 1988 |
| 21452 | Oxford Exploration Company | Denver, CO 80237 | Oil & Gas Operator | Aug 1995 |
| 21453 | Oxford Oil | Zanesville, OH 43702 | Oil & Gas Operator | Dec 2012 |
| 21454 | Oxford Oil Co. | Rockdale, TX 76567 | Oil & Gas Operator | Aug 2004 |
| 21455 | Oxford Oil Inc | Cleveland, OK 74020 | Oil & Gas Operator | Feb 1997 |
| 21456 | Oxley Energy LLC | Houston, TX 77042 | Gas Operator | Jun 2025 |
| 21457 | Oxley John C | Tulsa, OK 74103 | Oil & Gas Operator | Sep 1996 |
| 21458 | Oxley Petroleum | Tulsa, OK 74119-3609 | Oil & Gas Operator | Jan 2020 |
| 21459 | Oxley Petroleum Co | Oklahoma City, OK 73118-1044 | Oil & Gas Operator | Sep 2017 |
| 21460 | Oxson Co. | Uvalde, TX 78802 | Gas Operator | Oct 2025 |
| 21461 | Oxtex Inc | | Oil & Gas Operator | Oct 1989 |
| 21462 | Oxxn | Weatherford, TX 76086 | Oil & Gas Operator | Oct 2023 |
| 21463 | Oxy Little Knife, LLC | | Oil & Gas Operator | Jan 2016 |
| 21464 | Oxy Petroleum Inc | | Oil & Gas Operator | Jan 1986 |
| 21465 | Oxy USA | | Oil Operator | Apr 1992 |
| 21466 | Oxy USA Inc | Houston, TX 77046 | Oil & Gas Operator | Oct 2025 |
| 21467 | Oxy USA WTP Limited Partnership | Houston, TX 772104294 | Oil & Gas Operator | Jul 2025 |
| 21468 | Oxy USA WTP LP | Houston, TX 77046 | Oil & Gas Operator | Oct 2025 |
| 21469 | Oxyrock Operating, LLC | Houston, TX 77046 | Oil & Gas Operator | Oct 2025 |
| 21470 | Oz Gas Corporation | Austin, TX 78746 | Gas Operator | Oct 2025 |
| 21471 | Oz Gas LTD | Tidioute, PA 16351-2648 | Oil & Gas Operator | Dec 2016 |
| 21472 | Ozark Enterprise | | Oil Operator | Nov 1990 |
| 21473 | Ozark Exploration, Inc. | Dallas, TX 75205 | Oil & Gas Operator | Oct 2025 |
| 21474 | Ozark Oil Corporation | Springfield, MO 65804 | Oil & Gas Operator | Oct 1992 |
| 21475 | Ozark Oil LLC | Beallsville, OH 43716 | Oil & Gas Operator | Dec 2024 |
| 21476 | Ozark Production Company, Inc. | | Oil & Gas Operator | Jan 2025 |
| 21477 | Oztx Oil & Gas, L.L.C. | Ozona, TX 76943 | Oil & Gas Operator | Oct 2025 |
| 21478 | Ozzo Corporation, The | Bedford, TX 76021 | Oil Operator | Oct 2025 |
| 21479 | P & A Oilfield Services, Inc. | | Oil & Gas Operator | Jan 1998 |
| 21480 | P & A Operating, Inc. | Kerrville, TX 78028 | Oil & Gas Operator | Oct 2025 |
| 21481 | P & A Well Service | | Oil & Gas Operator | Jan 1994 |
| 21482 | P & C Energy Co | Allegany, NY 14706-9615 | Oil Operator | Dec 2015 |
| 21483 | P & C Oil & Gas, Inc. | Linn, WV 26384 | Oil & Gas Operator | Dec 2021 |
| 21484 | P & C Oil Company | Leona, TX 75850 | Oil & Gas Operator | Aug 2025 |
| 21485 | P & C Petroleum, LLC | Shawnee, KS 66226 | Oil Operator | Apr 2025 |
| 21486 | P & D Valentine Oil Co | New Matamoras, OH 45767 | Oil & Gas Operator | Dec 2018 |
| 21487 | P & E Oil | | Oil & Gas Operator | Dec 2024 |
| 21488 | P & H Construction Inc | Wewoka, OK 74884 | Oil & Gas Operator | Jun 2024 |
| 21489 | P & H Oil & Gas Inc | Stroud, OK 74079 | Oil & Gas Operator | Jul 2025 |
| 21490 | P & H Vacuum Service | | Oil & Gas Operator | Dec 2024 |
| 21491 | P & J Resources, Inc | | Oil & Gas Operator | Dec 2013 |
| 21492 | P & M Construction | Graham, TX 76450 | Oil & Gas Operator | Oct 2025 |
| 21493 | P & M Drilling Company Inc | Depew, OK 74028 | Oil & Gas Operator | Dec 2004 |
| 21494 | P & M Energy, A General Partnership | Johnson, KS 67855 | Gas Operator | Sep 2003 |
| 21495 | P & M Oil Company | Hays, KS 67601 | Oil & Gas Operator | Jul 2025 |
| 21496 | P & M Petroleum Management | Denver, CO BAD ADDR | Oil & Gas Operator | Apr 2010 |
| 21497 | P & M Petroleum Management, LLC | Denver, CO 80202 | Oil & Gas Operator | Oct 2021 |
| 21498 | P & P Petroleum | Midland, TX 79706 | Oil & Gas Operator | Oct 2002 |
| 21499 | P & P Producing Inc | Midland, TX 79702 | Oil & Gas Operator | Feb 2015 |
| 21500 | P & R Oil Company | Post, TX 79356 | Oil & Gas Operator | Oct 2025 |