| 20801 | Oleksandr Antonyuk | | Oil & Gas Operator | Dec 2018 |
| 20802 | Oleum Energy LLC | Georgetown, TX 78628 | Oil & Gas Operator | Jun 2024 |
| 20803 | Oleum Exploration, LLC | Brodheadsvill, PA 18322 | Oil & Gas Operator | Mar 2023 |
| 20804 | Oleum Incorporat | | Gas Operator | Dec 1990 |
| 20805 | Oleum Incorporated | | Oil & Gas Operator | Mar 1996 |
| 20806 | Oleum Operating Company, L.C. | Longview, TX 75606 | Oil & Gas Operator | Dec 2021 |
| 20807 | Oleum Operating La LLC | | Oil & Gas Operator | Nov 2022 |
| 20808 | Oleum Partners, LLC | Frisco, TX 75034 | Oil & Gas Operator | Sep 2024 |
| 20809 | Olia Oil & Gas Services LLC | Cedar Park, TX 78630-2049 | Oil & Gas Operator | Aug 2022 |
| 20810 | Oliditt Corporation | | Gas Operator | Mar 2022 |
| 20811 | Oliditt Production Inc. | | Gas Operator | Sep 1998 |
| 20812 | Olifant Energy LLC | Tulsa, OK 74119 | Oil & Gas Operator | Jun 2019 |
| 20813 | Olipdp II, LLC | Tulsa, OK 74119 | Oil & Gas Operator | Sep 2024 |
| 20814 | Oliphant Gertrud | Holdenville, OK 74848-0849 | Oil Operator | Aug 2013 |
| 20815 | Oliphant Operating LTD LLC | Tulsa, OK 74159-4529 | Oil Operator | Jun 2024 |
| 20816 | Olive Oil & Gas | Ellensboro, WV 26346 | Oil & Gas Operator | Dec 2021 |
| 20817 | Olive Oil & Gas Inc | Jennings, OK 74038 | Oil & Gas Operator | Apr 2024 |
| 20818 | Oliver Oil & Gas | Midland, TX 79702 | Oil & Gas Operator | Sep 2024 |
| 20819 | Olmos Partners, Inc. | Boerne, TX 78006 | Oil & Gas Operator | Sep 2024 |
| 20820 | Olney Oil LLC | Boerne, TX 78006 | Oil Operator | Sep 2024 |
| 20821 | Olney Properties, Inc. | Wichita Falls, TX 76307 | Oil & Gas Operator | Sep 2003 |
| 20822 | Olsan Brothers, Inc. | Dallas, TX 75251 | Oil & Gas Operator | Apr 1994 |
| 20823 | Olsen Energy Inc. | Boerne, TX 78006 | Oil & Gas Operator | Sep 2024 |
| 20824 | Olson D Producti | | Oil Operator | Jul 1994 |
| 20825 | Olson, S. A. | Kenedy, TX 78119 | Oil & Gas Operator | Aug 1994 |
| 20826 | Olson-Anderson Lease | | Oil Operator | Mar 2018 |
| 20827 | Oltex Production | Idalou, TX 79329 | Oil & Gas Operator | Sep 2024 |
| 20828 | Olympia Oil Inc | Edmond, OK 73083-7088 | Oil & Gas Operator | Jul 2020 |
| 20829 | Olympic Exploration & Production Co | Norman, OK 73072 | Oil Operator | May 2003 |
| 20830 | Olympic Exploration Inc | Denver, CO 80202 | Oil & Gas Operator | Jul 2004 |
| 20831 | Olympic Natural Gas Company | | Oil & Gas Operator | Oct 1990 |
| 20832 | Olympic Oil & Gas Co., Inc. | | Oil Operator | Apr 1991 |
| 20833 | Olympic Oil, Inc. | Hutchinson, KS 67502 | Oil & Gas Operator | May 2024 |
| 20834 | Olympic Petroleu | | Oil & Gas Operator | Jul 1993 |
| 20835 | Olympic Petroleum Company | Tulsa, OK 74114 | Oil & Gas Operator | Jun 1998 |
| 20836 | Olympic Production Company | | Oil & Gas Operator | Jul 1994 |
| 20837 | Olympic Resources Co | Wooster, OH 44691 | Oil & Gas Operator | Dec 2000 |
| 20838 | Olympus Energy, LLC | Canonsburg, PA 15317 | Gas Operator | Jul 2024 |
| 20839 | Olympus Prop Inc | Franklin Park, IL 60131-1418 | Oil & Gas Operator | Dec 1997 |
| 20840 | Omac Oil & Gas Co | Newark, OH 43055 | Oil & Gas Operator | Dec 1990 |
| 20841 | Omar Operating Company | Midland, TX 79702 | Oil & Gas Operator | Sep 2013 |
| 20842 | Omber Petroleum & Energy Corp. | New Braunfels, TX 78131 | Oil & Gas Operator | Sep 2024 |
| 20843 | Omeara Bros. | | Oil & Gas Operator | Oct 1982 |
| 20844 | Omega Alpha Resources, LLC | Dallas, TX 75219 | Oil Operator | Sep 2024 |
| 20845 | Omega Energy Corp. | Graham, TX 76450 | Oil & Gas Operator | Sep 2024 |
| 20846 | Omega Energy Incorporated | | Oil & Gas Operator | May 1998 |
| 20847 | Omega Energy, LLC | Corpus Chrsti, TX 78418 | Oil & Gas Operator | Sep 2024 |
| 20848 | Omega Enterprise | | Oil Operator | Sep 1990 |
| 20849 | Omega Oil Corp | Lafayette, IN 47903 | Oil & Gas Operator | Dec 1987 |
| 20850 | Omega Operating, Inc. | Odessa, TX 79769 | Oil & Gas Operator | Mar 2001 |
| 20851 | Omega Resources Inc | | Oil & Gas Operator | Nov 1998 |
| 20852 | Omimex Canada, LTD. | Fort Worth, TX 76120-3608 | Oil & Gas Operator | Jun 2024 |
| 20853 | Omimex Energy, Inc. | Fort Worth, TX 76120 | Oil & Gas Operator | Jan 2024 |
| 20854 | Omimex International Corporation | Fort Worth, TX 76103-2300 | Oil & Gas Operator | Jun 2024 |
| 20855 | Omimex Petroleum Inc | Fort Worth, TX 76120 | Oil & Gas Operator | Aug 2022 |
| 20856 | Omimex Petroleum Inc (Co) | Newcastle, WY 82701 | Oil & Gas Operator | May 2001 |
| 20857 | Omimex Petroleum Inc (De) | Fort Worth, TX 76120 | Oil & Gas Operator | Aug 2020 |
| 20858 | Omni E & P, Inc. | San Antonio, TX 78229 | Oil Operator | Apr 2010 |
| 20859 | Omni Oil & Gas, Inc. | San Antonio, TX 78229 | Oil & Gas Operator | Oct 2017 |
| 20860 | Omni Operating Company | Osage, WY 82723 | Oil & Gas Operator | Sep 2001 |
| 20861 | Omni Operating Company(A) | Dallas, TX 75370 | Oil & Gas Operator | Sep 2024 |
| 20862 | Omni Petroleum Corporation | Austin, TX 78738 | Oil & Gas Operator | Sep 2024 |
| 20863 | Omr Drilling & Acquisition LLC | Albany, KY 42602 | Oil Operator | Dec 2015 |
| 20864 | On Pointe Operating LLC | Austin, TX 78746 | Oil & Gas Operator | Sep 2024 |
| 20865 | On-Line Oil Inc | Oklahoma City, OK 73105-5208 | Oil & Gas Operator | Mar 2015 |
| 20866 | Onapa Gas Company LLC | Tulsa, OK 74136-7253 | Gas Operator | Nov 2019 |
| 20867 | Onaroll Operating LLC | Levelland, TX 79336 | Oil Operator | Sep 2024 |
| 20868 | Onco Petroleum USA Inc | | Oil Operator | Dec 2009 |
| 20869 | One Epoch Energy, Inc. | Abilene, TX 79604 | Oil & Gas Operator | Mar 2008 |
| 20870 | One Nickel Operating LLC | Westbrook, TX 79565 | Oil Operator | Sep 2024 |
| 20871 | One Source Financial Services Inc. | McAllen, TX 78501 | Gas Operator | Dec 2019 |
| 20872 | One Tec Operating, LLC | Houston, TX 77002 | Oil & Gas Operator | Feb 2011 |
| 20873 | One World Operating, LLC | Tampa, FL 33602 | Oil & Gas Operator | Sep 2024 |
| 20874 | Oneenergy Partners Operating, LLC | Houston, TX 77019 | Oil & Gas Operator | Nov 2018 |
| 20875 | Oneida Energy Corporation | Tulsa, OK 74137 | Oil & Gas Operator | Jul 2003 |
| 20876 | Oneok Energy Service | | Gas Operator | Dec 2008 |
| 20877 | Oneok Exploratio | | Oil & Gas Operator | Mar 1995 |
| 20878 | Oneok Exploration Company | Tulsa, OK 74102 | Oil & Gas Operator | Feb 2017 |
| 20879 | Oneok Field Services Company | Tulsa, OK 74103 | Oil & Gas Operator | Jul 2022 |
| 20880 | Oneok Gas Processing LLC | Tulsa, OK 74103 | Oil & Gas Operator | May 2018 |
| 20881 | Oneok Gas Transportation Co | Tulsa, OK 74121-2089 | Oil & Gas Operator | Oct 2014 |
| 20882 | Oneok Resources Company | Tulsa, OK 74102 | Oil & Gas Operator | Feb 2017 |
| 20883 | Onexxx Prod & Exploration Corp | Jeannette, PA 15644-9691 | Gas Operator | Dec 2023 |
| 20884 | Onnen, Gerhard E. | Yates Center, KS 66783 | Oil Operator | Feb 2002 |
| 20885 | Onpoint Oil & Gas LLC | Oklahoma City, OK 73170-4848 | Oil & Gas Operator | Jun 2024 |
| 20886 | Onshore Exp Cor-La Nat Res Inc | | Oil & Gas Operator | Oct 1978 |
| 20887 | Onshore Pipeline Const Co Inc | | Oil & Gas Operator | Aug 1998 |
| 20888 | Onshore Royalties LLC | Houston, TX 77269 | Oil & Gas Operator | Jul 2024 |
| 20889 | Onshore, L.L.C. | Wichita, KS 67205 | Oil & Gas Operator | Dec 2009 |
| 20890 | Onyx Energy Corporation | Oklahoma City, OK 73157 | Oil & Gas Operator | May 1994 |
| 20891 | Onyx Energy Dev Of Texas Inc. | | Oil Operator | Dec 1996 |
| 20892 | Onyx Energy Of Texas Inc. | | Oil Operator | Dec 1996 |
| 20893 | Onyx Industries LTD, Inc. | Wichita Falls, TX 76308 | Oil & Gas Operator | Aug 2003 |
| 20894 | Onyx Int'L Exploration LLC | | Oil & Gas Operator | Dec 2015 |
| 20895 | Onyx Producing Company, Inc. | Pampa, TX 79066 | Oil & Gas Operator | Mar 2008 |
| 20896 | Onyx Properties Corp | Oklahoma City, OK 73114 | Oil & Gas Operator | May 2006 |
| 20897 | Onyxx Energy LLC | | Oil & Gas Operator | Mar 2017 |
| 20898 | Onyxx Oil Corpor | | Oil Operator | Jul 1992 |
| 20899 | Oolite Energy Corp | Amarillo, TX 79105 | Oil & Gas Operator | Apr 2022 |
| 20900 | Oonk, Harvey D. | Clymer, NY 14724 | Gas Operator | Dec 2023 |