| 20901 | Obax Oil And Gas LLC | Saint Louis, MO 63131 | Oil Operator | Oct 2025 |
| 20902 | Obele Oil Corporation | Sedona, AZ 86336-5745 | Oil & Gas Operator | May 2017 |
| 20903 | Obele Operating Company LLC | Sedona, AZ 86336-5745 | Oil & Gas Operator | Jun 2025 |
| 20904 | Oberlander Leslie A Jake | Covington, OK 73730 | Oil Operator | Jun 2007 |
| 20905 | Obermiller Clarence Trust | Creston, OH 44217 | Oil & Gas Operator | Dec 1987 |
| 20906 | Obermiller Paul J | Creston, OH 44217 | Oil & Gas Operator | Dec 2014 |
| 20907 | Oblaen Resources LLC | Wallis, TX 77485 | Oil & Gas Operator | Oct 2025 |
| 20908 | Occ Operating Co. | | Oil & Gas Operator | Apr 2019 |
| 20909 | Occam Petroleum E&P, LLC | Meeker, OK 74855 | Oil Operator | Oct 2025 |
| 20910 | Occidental Energy Company, Inc. | Houston, TX 77282 | Oil & Gas Operator | Jul 2021 |
| 20911 | Occidental Energy Marketing, Inc. | Houston, TX 77227 | Gas Operator | Sep 2015 |
| 20912 | Occidental Of Elk Hills Inc. | | Oil & Gas Operator | Dec 2014 |
| 20913 | Occidental Permian LTD. | Houston, TX 77046 | Oil & Gas Operator | Oct 2025 |
| 20914 | Occidental Petroleum Corporation | | Oil & Gas Operator | Dec 2021 |
| 20915 | Occidental W TX Overthrust, Inc. | Houston, TX 77210 | Oil & Gas Operator | Dec 2021 |
| 20916 | Ocean Energy Inc Ndba Devon Louisiana Corp | | Oil & Gas Operator | Jul 2001 |
| 20917 | Ocean Energy Resources Inc. | Houston, TX 77002 | Oil & Gas Operator | Mar 2025 |
| 20918 | Ocean Energy, Inc. | Houston, TX 77002 | Oil & Gas Operator | Aug 2003 |
| 20919 | Ocfiw Oil Company, Inc. | Hartington, NE 68739 | Oil & Gas Operator | Dec 2009 |
| 20920 | Ochiltree Oil Company | Edmond, OK 73034 | Oil & Gas Operator | Apr 2020 |
| 20921 | Oci LLC | Thermopolis, WY 82443 | Oil Operator | Jan 2024 |
| 20922 | Ocotillo Energy Resources, LLC | Odessa, TX 79765 | Oil Operator | Oct 2025 |
| 20923 | Octagon Resources Corporation | | Oil Operator | Apr 2005 |
| 20924 | Octagon Resources LLC | Norman, OK 73071-1295 | Oil & Gas Operator | May 2015 |
| 20925 | Octane Energy Operating, LLC | Midland, TX 79701 | Oil & Gas Operator | Oct 2025 |
| 20926 | Odebralski, Michael & Connie | Fredonia, NY 14063 | Gas Operator | Dec 2024 |
| 20927 | Odegard Energy, Inc. | Houston, TX 77024 | Oil & Gas Operator | Jul 2020 |
| 20928 | Odegard Resources/Omni Exp | Columbus, OH 43207 | Oil & Gas Operator | Sep 1986 |
| 20929 | Odell Larry | Oologah, OK 74053 | Oil Operator | Apr 2011 |
| 20930 | Oden, Robin H., Inc. | Midland, TX 79702 | Oil & Gas Operator | Apr 1994 |
| 20931 | Odessa Exploration, Inc. | Midland, TX 79702 | Oil & Gas Operator | Oct 2025 |
| 20932 | Odessa Oil Investment Co., Inc. | Odessa, TX 79762 | Oil & Gas Operator | Nov 2016 |
| 20933 | Odom, Claude | | Oil Operator | Jul 1983 |
| 20934 | Odom, R. H. | Snyder, TX 79550 | Oil & Gas Operator | Jun 1996 |
| 20935 | Odom, Ralph R. | | Oil & Gas Operator | Aug 1993 |
| 20936 | Odum Oil & Gas Co. | Harper, TX 78631 | Oil & Gas Operator | Oct 2025 |
| 20937 | Odum Ronald L | Garfield, AR 72732 | Oil Operator | May 2025 |
| 20938 | Ody Oil Corp. | | Oil & Gas Operator | Oct 1994 |
| 20939 | Odyssey Operating Company | Shreveport, LA 71106 | Oil & Gas Operator | Sep 2020 |
| 20940 | Odyssey Petroleum Company | Houston, TX 77010 | Oil & Gas Operator | Apr 1995 |
| 20941 | Odyssey Petroleum Corp. | | Oil & Gas Operator | Jun 2011 |
| 20942 | Oedekoven Amerifields Resources LLC | Sugar Land, TX 77478 | Oil Operator | Jun 2025 |
| 20943 | Oedekoven Water & Hot Oil | Recluse, WY 82725 | Oil & Gas Operator | Sep 2025 |
| 20944 | Oeth DRLG Co | | Oil Operator | Dec 2018 |
| 20945 | Oex-1 LLC | Tulsa, OK 74105-5153 | Oil & Gas Operator | Mar 2024 |
| 20946 | Oexco, Inc. | Tulsa, OK 74136 | Oil & Gas Operator | Mar 2015 |
| 20947 | Off Broadway Mineral Rights LLC | | Oil & Gas Operator | Oct 2024 |
| 20948 | Offield Lease Operations LLC | Wilson, OK 73463 | Oil & Gas Operator | May 2023 |
| 20949 | Offset Oil & Gas | Big Spring, TX 79720 | Oil & Gas Operator | Aug 2003 |
| 20950 | Offshore Group, Inc. The | Houston, TX 77024 | Oil & Gas Operator | Oct 2025 |
| 20951 | Offshore Oil & Gas Inc | Houston, TX 77063 | Oil & Gas Operator | Sep 1994 |
| 20952 | Offshore Shelf LLC | | Oil & Gas Operator | Dec 2007 |
| 20953 | Ofs-Tulsa Corporation | Fort Worth, TX 76102 | Oil & Gas Operator | Feb 1997 |
| 20954 | Oft Inc. | Houston, TX 77079 | Oil & Gas Operator | Oct 2025 |
| 20955 | Og Co., Inc. | Houston, TX 77057 | Oil & Gas Operator | Oct 2025 |
| 20956 | Oga Operating L.L.C. | Midland, TX 79702 | Oil & Gas Operator | Jan 2000 |
| 20957 | Ogden Oil Co., Inc. | | Oil Operator | May 1981 |
| 20958 | Ogden Resources Corporation | Bryan, TX 77802 | Oil & Gas Operator | Oct 2025 |
| 20959 | Ogden Resources, LTD. | Bryan, TX 77802 | Oil & Gas Operator | Feb 2009 |
| 20960 | Ogh Oil Company | | Oil Operator | Sep 1995 |
| 20961 | Ogle Petroleum Inc. | | Oil & Gas Operator | Dec 1989 |
| 20962 | Oglesby Oil Company | | Oil & Gas Operator | Nov 2023 |
| 20963 | Oglesby Prod & Expl Co Inc | | Oil & Gas Operator | Nov 1987 |
| 20964 | Oglesby, Marshall | | Oil Operator | May 1990 |
| 20965 | Ogog Operating, LLC | Dallas, TX 75367 | Oil & Gas Operator | Oct 2025 |
| 20966 | Ogris Operating, LLC | Midland, TX 79710 | Oil & Gas Operator | Oct 2025 |
| 20967 | Ogs Operating Company, Inc. | Midland, TX 79701 | Oil & Gas Operator | Sep 2008 |
| 20968 | Ogx Operating, LLC | Midland, TX 79702 | Oil & Gas Operator | Oct 2025 |
| 20969 | Ogx Resources LLC | Midland, TX 79702 | Oil & Gas Operator | Oct 2011 |
| 20970 | Ohio Energy Assets, Inc. | Laurelville, OH 43135 | Oil & Gas Operator | Dec 2014 |
| 20971 | Ohio Energy Group Inc | Uniontown, OH 44685 | Oil & Gas Operator | Dec 1988 |
| 20972 | Ohio Energy Operators LLC | Colorado Spring, CO 80908 | Oil Operator | Dec 2018 |
| 20973 | Ohio Investment Leas Inc | Danville, OH 43014 | Oil & Gas Operator | Dec 1989 |
| 20974 | Ohio Kentucky Oil Corporation | Lexington, KY 40503 | Oil & Gas Operator | Dec 2023 |
| 20975 | Ohio L & M Company Inc | Marietta, OH 45750 | Oil & Gas Operator | Dec 2008 |
| 20976 | Ohio Natural Fuel Co | Canton, OH 44718 | Oil & Gas Operator | Dec 1985 |
| 20977 | Ohio Oil & Gas | Fowler, OH 44418 | Oil & Gas Operator | Dec 1988 |
| 20978 | Ohio Production Corp | Westerville, OH 43081 | Oil & Gas Operator | Dec 2001 |
| 20979 | Ohio Production* | Newark, OH 43055 | Oil & Gas Operator | Dec 1987 |
| 20980 | Ohio Valley Energy Systems Corp | Austintown, OH 44515 | Oil & Gas Operator | Dec 2024 |
| 20981 | Ohio Valley Energy, Inc | Livermore, KY 42352 | Oil Operator | Dec 2023 |
| 20982 | Ohlhausen Oil Company | Abilene, TX 79608 | Oil & Gas Operator | Oct 2025 |
| 20983 | Oi Auburn, Inc. | Tulsa, OK 74135 | Gas Operator | Dec 2024 |
| 20984 | Oil & Gas Acquisition Group Inc | Austin, TX 78716 | Oil & Gas Operator | May 2003 |
| 20985 | Oil & Gas Development Company | | Oil & Gas Operator | May 1991 |
| 20986 | Oil & Gas Exploration Inc | Cleveland, OK 74020 | Oil & Gas Operator | Aug 2013 |
| 20987 | Oil & Gas MGMT Inc | Mount Pleasant, PA 15666-3304 | Oil & Gas Operator | Dec 2024 |
| 20988 | Oil & Gas Operations | Midland, TX 79706 | Oil & Gas Operator | Oct 2025 |
| 20989 | Oil & Gas Producers, Inc. | Topeka, KS 66604 | Oil Operator | Jun 2004 |
| 20990 | Oil & Gas Properties | Midland, TX 79704 | Oil & Gas Operator | Oct 2025 |
| 20991 | Oil & Gas Property MGMT., Inc. | Dallas, TX 75201 | Oil & Gas Operator | Jul 1996 |
| 20992 | Oil & Gas Servic | | Oil Operator | Jun 1983 |
| 20993 | Oil & Gas Solutions LTD | Wooster, OH 44691 | Oil & Gas Operator | Dec 2007 |
| 20994 | Oil & Gas SVC Inc | Reelsville, IN 46171-9686 | Gas Operator | Dec 1991 |
| 20995 | Oil & Gas Unlimited Inc | | Oil & Gas Operator | May 2013 |
| 20996 | Oil & Realty Devlop Inc | Columbus, OH 43212 | Oil Operator | Dec 1986 |
| 20997 | Oil And Gas Futures, Inc. | | Oil & Gas Operator | May 1977 |
| 20998 | Oil Capital Corporation | Littleton, CO 80122 | Gas Operator | May 2009 |
| 20999 | Oil Center Operating Inc | Fort Worth, TX 76102-5108 | Oil & Gas Operator | Apr 2014 |
| 21000 | Oil Coast Corp. | S Houston, TX 77587 | Oil & Gas Operator | Oct 2025 |