| 20701 | Oklahoma Petroleum MGMT Corp | Tulsa, OK 74119 | Oil & Gas Operator | Jun 1993 |
| 20702 | Oklahoma Prime Energy LLC | Ardmore, OK 73401 | Oil Operator | May 2020 |
| 20703 | Oklahoma Prod & Exp Co | Broken Arrow, OK 74012 | Oil & Gas Operator | May 2013 |
| 20704 | Oklahoma RB Operating Company | Midland, TX 79701 | Oil & Gas Operator | Jan 1998 |
| 20705 | Oklahoma Rig & Salvage Inc | Oklahoma City, OK 73114 | Oil & Gas Operator | Mar 2015 |
| 20706 | Oklahoma SWD Systems Inc | Odessa, TX 79762-8132 | Oil & Gas Operator | Jan 2026 |
| 20707 | Oklahoma Tank Service Inc | Oklahoma City, OK 73143 | Oil Operator | Aug 1997 |
| 20708 | Okland Oil Company | Oklahoma City, OK 73102-9022 | Oil & Gas Operator | Feb 2026 |
| 20709 | Oklaoleum Oil And Gas Inc | Bristow, OK 74010-0057 | Oil Operator | Jan 2016 |
| 20710 | Oklatex Energy, Inc. | Beaumont, TX 77702 | Oil Operator | Apr 2026 |
| 20711 | Okmar Oil Compan | | Oil & Gas Operator | Feb 1995 |
| 20712 | Okmar Oil Company | Marietta, OH 45750 | Oil & Gas Operator | Jun 2005 |
| 20713 | Okreek Oil Company | Weatherford, TX 76086 | Oil & Gas Operator | Apr 2026 |
| 20714 | Okt Petroleum Company Inc | Oklahoma City, OK 73118-7425 | Oil & Gas Operator | Oct 2013 |
| 20715 | Okt Resources, LLC | Edmond, OK 73013 | Oil & Gas Operator | Apr 2026 |
| 20716 | Oktex Operating LLC | Edmond, OK 73013-1961 | Oil & Gas Operator | May 2020 |
| 20717 | Oky Investments, Inc. | Edmond, OK 73013 | Oil & Gas Operator | Sep 2021 |
| 20718 | Ol' Boys Operations LLC | Pampa, TX 79065 | Oil & Gas Operator | Apr 2026 |
| 20719 | Ol' Oily LLC | | Oil Operator | Dec 2025 |
| 20720 | Old Acres Farm, Inc. | Perry, NY 14530 | Gas Operator | Dec 2024 |
| 20721 | Old Cedron, L.L.C. | Lubbock, TX 79410 | Oil & Gas Operator | May 2004 |
| 20722 | Old Chief Oil, LLC | San Antonio, TX 78205 | Oil Operator | Apr 2026 |
| 20723 | Old Dominion Oil Corporation | Oklahoma City, OK 73107 | Oil & Gas Operator | Apr 2009 |
| 20724 | Old Field Associates | | Oil & Gas Operator | Dec 2025 |
| 20725 | Old MTN Gas Co Inc | Pleasantville, PA 16341-0329 | Oil & Gas Operator | Dec 2020 |
| 20726 | Old Pine Energy Corporation | Austin, TX 78755 | Oil Operator | Apr 2026 |
| 20727 | Old South Oil LLC | Marietta, OH 45750 | Oil & Gas Operator | Dec 2025 |
| 20728 | Old Timers Oil | Saratoga, TX 77585 | Oil & Gas Operator | Nov 2014 |
| 20729 | Old Timers Oil Company, LLC | Saratoga, TX 77585 | Oil Operator | Aug 2022 |
| 20730 | Old Timers Oil No. 2 Incorporated | Saratoga, TX 77585 | Oil Operator | Apr 2026 |
| 20731 | Old Union Operating Company | Austin, TX 78716 | Oil & Gas Operator | Apr 2026 |
| 20732 | Olde Chautauqua Farms | Portland, NY 14769 | Gas Operator | Dec 2024 |
| 20733 | Older Than Dirt LLC | Weatherford, TX 76086 | Oil & Gas Operator | Apr 2026 |
| 20734 | Oldfield Acquisition LP | Austin, TX 78733 | Oil & Gas Operator | Sep 1996 |
| 20735 | Oldfield Operating Corporation | | Oil Operator | Dec 2013 |
| 20736 | Olds Oil Company | Casper, WY 82604 | Oil Operator | Jun 1988 |
| 20737 | Ole Chaparral On Possum Kingdom | Wichita Falls, TX 76307 | Oil & Gas Operator | Dec 1997 |
| 20738 | Ole Crow Operating | Wichita Falls, TX 76308 | Oil Operator | Jan 2026 |
| 20739 | Ole Miss Oil & Gas Inc | New Bremen, OH 45689 | Oil & Gas Operator | Dec 1985 |
| 20740 | Ole, Inc. | Graham, TX 76450 | Oil & Gas Operator | Aug 2003 |
| 20741 | Oleksandr Antonyuk | | Oil & Gas Operator | Dec 2018 |
| 20742 | Olenox Corp. | Katy, TX 77449 | Oil Operator | Apr 2026 |
| 20743 | Oleum Energy LLC | Georgetown, TX 78628 | Oil & Gas Operator | Feb 2026 |
| 20744 | Oleum Exploration, LLC | Brodheadsvill, PA 18322 | Oil & Gas Operator | Mar 2023 |
| 20745 | Oleum Inc | | Oil & Gas Operator | Mar 1996 |
| 20746 | Oleum Incorporat | | Gas Operator | Dec 1990 |
| 20747 | Oleum Operating Company, L.C. | Longview, TX 75606 | Oil & Gas Operator | Dec 2021 |
| 20748 | Oleum Operating La LLC | | Oil & Gas Operator | Nov 2022 |
| 20749 | Oleum Partners, LLC | Frisco, TX 75034 | Oil & Gas Operator | Apr 2026 |
| 20750 | Olia Oil & Gas Services LLC | Cedar Park, TX 78630-2049 | Oil & Gas Operator | Aug 2022 |
| 20751 | Oliditt Corporation | | Gas Operator | Mar 2022 |
| 20752 | Oliditt Production Inc. | | Gas Operator | Sep 1998 |
| 20753 | Olifant Energy LLC | Tulsa, OK 74119 | Oil & Gas Operator | Jun 2019 |
| 20754 | Olipdp II, LLC | Lafayette, LA 70503 | Oil & Gas Operator | Apr 2026 |
| 20755 | Oliphant Gertrud | Holdenville, OK 74848-0849 | Oil Operator | Aug 2013 |
| 20756 | Oliphant Operating Co,LTD,LLC | | Oil Operator | Feb 2026 |
| 20757 | Olive Oil & Gas Inc | Jennings, OK 74052 | Oil & Gas Operator | Jan 2026 |
| 20758 | Oliver Oil & Gas | Midland, TX 79702 | Oil & Gas Operator | Apr 2026 |
| 20759 | Olmos Partners, Inc. | Boerne, TX 78006 | Oil & Gas Operator | Apr 2026 |
| 20760 | Olney Oil LLC | Boerne, TX 78006 | Oil Operator | Apr 2026 |
| 20761 | Olney Properties, Inc. | Wichita Falls, TX 76307 | Oil & Gas Operator | Sep 2003 |
| 20762 | Olsan Brothers, Inc. | Dallas, TX 75251 | Oil & Gas Operator | Apr 1994 |
| 20763 | Olsen Energy Inc. | Boerne, TX 78006 | Oil & Gas Operator | Apr 2026 |
| 20764 | Olson D Producti | | Oil Operator | Jul 1994 |
| 20765 | Olson, S. A. | Kenedy, TX 78119 | Oil & Gas Operator | Aug 1994 |
| 20766 | Olson-Anderson Lease | | Oil Operator | Mar 2018 |
| 20767 | Oltex Production | Idalou, TX 79329 | Oil & Gas Operator | Apr 2026 |
| 20768 | Olympia Oil Inc | Edmond, OK 73083-7088 | Oil & Gas Operator | Jul 2020 |
| 20769 | Olympic Exploration & Production Co | Norman, OK 73072 | Oil Operator | May 2003 |
| 20770 | Olympic Exploration Inc | Denver, CO 80202 | Oil & Gas Operator | Jul 2004 |
| 20771 | Olympic Natural Gas Company | | Oil & Gas Operator | Oct 1990 |
| 20772 | Olympic Oil & Gas Co., Inc. | | Oil Operator | Apr 1991 |
| 20773 | Olympic Oil, Inc. | Hutchinson, KS 67502 | Oil & Gas Operator | Jul 2025 |
| 20774 | Olympic Petroleu | | Oil & Gas Operator | Jul 1993 |
| 20775 | Olympic Petroleum Co | Tulsa, OK 74114 | Oil & Gas Operator | Jun 1998 |
| 20776 | Olympic Production Company | | Oil & Gas Operator | Jul 1994 |
| 20777 | Olympic Resources Co | Wooster, OH 44691 | Oil & Gas Operator | Dec 2000 |
| 20778 | Olympus Energy, LLC | Canonsburg, PA 15317-7536 | Gas Operator | Jun 2025 |
| 20779 | Olympus Prop Inc | Franklin Park, IL 60131-1418 | Oil & Gas Operator | Dec 1997 |
| 20780 | Omac Oil & Gas Co | Newark, OH 43055 | Oil & Gas Operator | Dec 1990 |
| 20781 | Omar Operating Company | Midland, TX 79702 | Oil & Gas Operator | Sep 2013 |
| 20782 | Omber Petroleum & Energy Corp. | New Braunfels, TX 78131 | Oil & Gas Operator | Apr 2026 |
| 20783 | Omeara Bros. | | Oil & Gas Operator | Oct 1982 |
| 20784 | Omega Alpha Resources, LLC | Dallas, TX 75219 | Oil Operator | Apr 2026 |
| 20785 | Omega Energy Corp. | Graham, TX 76450 | Oil & Gas Operator | Apr 2026 |
| 20786 | Omega Energy Incorporated | | Oil & Gas Operator | May 1998 |
| 20787 | Omega Energy, LLC | Corpus Chrsti, TX 78418 | Oil & Gas Operator | Apr 2026 |
| 20788 | Omega Enterprise | | Oil Operator | Sep 1990 |
| 20789 | Omega Oil Corp | Lafayette, IN 47903 | Oil & Gas Operator | Dec 1987 |
| 20790 | Omega Operating, Inc. | Odessa, TX 79769 | Oil & Gas Operator | Mar 2001 |
| 20791 | Omega Resources Inc | | Oil & Gas Operator | Nov 1998 |
| 20792 | Omimex Canada, LTD. | Fort Worth, TX 76120-3608 | Oil & Gas Operator | Jan 2026 |
| 20793 | Omimex Energy, Inc. | Fort Worth, TX 76120 | Oil & Gas Operator | Aug 2025 |
| 20794 | Omimex International Corp | Fort Worth, TX 76103-2300 | Oil & Gas Operator | Jan 2026 |
| 20795 | Omimex Petroleum Inc | Fort Worth, TX 76120 | Oil & Gas Operator | Aug 2022 |
| 20796 | Omimex Petroleum Inc (Co) | Newcastle, WY 82701 | Oil & Gas Operator | May 2001 |
| 20797 | Omimex Petroleum Inc (De) | Fort Worth, TX 76120 | Oil & Gas Operator | Aug 2020 |
| 20798 | Omni E & P, Inc. | San Antonio, TX 78229 | Oil Operator | Apr 2010 |
| 20799 | Omni Oil & Gas, Inc. | San Antonio, TX 78229 | Oil & Gas Operator | Oct 2017 |
| 20800 | Omni Operating Company | Osage, WY 82723 | Oil & Gas Operator | Sep 2001 |