| 2001 | Commerce Energy, Inc. | | Oil & Gas Operator | Dec 1999 |
| 2002 | Commerce Oil & Gas Co | Rocky River, OH 44116 | Oil & Gas Operator | Dec 1996 |
| 2003 | Commercial Energ | | Gas Operator | Oct 1996 |
| 2004 | Commercial Oil - | | Oil Operator | Apr 1994 |
| 2005 | Commercial Oil Company, Inc. | Wichita, KS 67204 | Oil Operator | Jun 2001 |
| 2006 | Commodore Energy Co | Rolling Hills, CA 90274-5265 | Oil & Gas Operator | Dec 2007 |
| 2007 | Common Energy Inc | Douglas, WY 82633 | Oil & Gas Operator | Aug 1995 |
| 2008 | Common Resources L.L.C. | The Woodlands, TX 77380 | Oil & Gas Operator | May 2010 |
| 2009 | Commonwealth Energy, Inc. | Weston, WV 26452-0000 | Oil & Gas Operator | Dec 2021 |
| 2010 | Commonwealth Pet | | Oil & Gas Operator | Nov 1995 |
| 2011 | Commonwealth Resources, LLC | Fort Collins, CO 80524 | Oil Operator | Dec 2008 |
| 2012 | Commonwealth Royalty, LLC | Balmorhea, TX 79718 | Oil Operator | Apr 2025 |
| 2013 | Compadre Drilling & Expl Corp | Ardmore, OK 73402 | Oil & Gas Operator | Mar 2015 |
| 2014 | Compadres, Inc. | | Oil & Gas Operator | Dec 1988 |
| 2015 | Compass Drilling Inc | Enid, OK 73702-5467 | Oil & Gas Operator | Sep 2014 |
| 2016 | Compass Energy Operating, LLC | Tulsa, OK 74136 | Oil & Gas Operator | Apr 2025 |
| 2017 | Compass Energy, Inc. | Shelby, MT 59474 | Gas Operator | Feb 2007 |
| 2018 | Compass Global Resources LLC | | Oil & Gas Operator | Dec 2015 |
| 2019 | Compass Operating, L.L.C. | Midland, TX 79702 | Oil & Gas Operator | Apr 2025 |
| 2020 | Compass Resources | Enid, OK 73702 | Oil & Gas Operator | Dec 2007 |
| 2021 | Complete Energy Services LLC | Gainesville, TX 76240 | Oil Operator | Aug 2022 |
| 2022 | Compostella Oil Company | Midland, TX 79702 | Oil & Gas Operator | Mar 2008 |
| 2023 | Compressor Syste | | Oil Operator | May 1991 |
| 2024 | Compro Services Inc | Williamstown, WV 26187 | Oil & Gas Operator | Dec 1985 |
| 2025 | Comstock Energy, LLC | Wichita Falls, TX 76301 | Oil & Gas Operator | Apr 2025 |
| 2026 | Comstock Offshore, LLC | | Oil & Gas Operator | Nov 2004 |
| 2027 | Comstock Oil & Gas -- La, Inc. | | Oil & Gas Operator | Mar 2005 |
| 2028 | Comstock Oil & Gas, Inc. | Frisco, TX 75034 | Oil & Gas Operator | Dec 2012 |
| 2029 | Comstock Oil & Gas, LLC | Frisco, TX 75034 | Oil & Gas Operator | Apr 2025 |
| 2030 | Comstock Oil & Gas, LP | Frisco, TX 75034 | Oil & Gas Operator | Aug 2019 |
| 2031 | Comstock Oil & Gas--La, LLC | | Oil & Gas Operator | Dec 2024 |
| 2032 | Comyn Natural Gas, Inc. | Fort Worth, TX 76163 | Oil & Gas Operator | Apr 2025 |
| 2033 | Con-Lin Oil Co. | Graham, TX 76450 | Oil & Gas Operator | Nov 2017 |
| 2034 | Conch Oil, Inc. | Wichita, KS 67202 | Oil Operator | Jun 2002 |
| 2035 | Concho Exploration | Midland, TX 79701 | Oil & Gas Operator | Feb 2004 |
| 2036 | Concho Exploration Inc | Oklahoma City, OK 73154 | Oil & Gas Operator | Mar 2015 |
| 2037 | Concho Oil & Gas Corp. | Midland, TX 79701 | Oil & Gas Operator | May 2003 |
| 2038 | Concho Oilfield Serv & Oper Co. | Eden, TX 76837 | Oil & Gas Operator | Apr 2025 |
| 2039 | Concho Oilfield Service, Inc. | Albany, TX 76430 | Oil & Gas Operator | Apr 2013 |
| 2040 | Concho Petroleum | | Oil & Gas Operator | Dec 1994 |
| 2041 | Concho Resources Inc. | Oklahoma City, OK 73154 | Oil & Gas Operator | Mar 2004 |
| 2042 | Concor Petroleum, Inc. | | Oil & Gas Operator | Feb 1983 |
| 2043 | Concord Energy LLC | Denver, CO 80202 | Oil & Gas Operator | Jan 2021 |
| 2044 | Concord Energy, Inc. | Glen Rose, TX 76043 | Oil & Gas Operator | Apr 2025 |
| 2045 | Concord Operating Incorporated | Horseshoe Bay, TX 78657 | Oil & Gas Operator | Dec 2008 |
| 2046 | Concord Resources, LLC | | Oil & Gas Operator | Nov 2000 |
| 2047 | Concorde Exploration, Inc. | Dallas, TX 75206 | Oil & Gas Operator | Oct 1994 |
| 2048 | Concorde Resources Corporation | Eufaula, OK 74432 | Oil & Gas Operator | Feb 2025 |
| 2049 | Concordia Resources Inc. | | Oil & Gas Operator | Dec 2024 |
| 2050 | Condor Energy | | Oil Operator | Aug 1995 |
| 2051 | Condor Energy Inc | Great Bend, KS 67530 | Oil & Gas Operator | Oct 2021 |
| 2052 | Condor Energy Technology LLC | | Oil & Gas Operator | Jul 2018 |
| 2053 | Condor Exploration LLC | Greenwood VIllage, CO 80111 | Oil & Gas Operator | Sep 2009 |
| 2054 | Condor Oil Company Inc. | | Oil & Gas Operator | Dec 2000 |
| 2055 | Condor Oil Corp | Boulder, CO 80303 | Oil & Gas Operator | Dec 1994 |
| 2056 | Condor Operating Co. | Midland, TX 79702 | Oil & Gas Operator | Feb 2015 |
| 2057 | Condor Operating Company, LLC | Midland, TX 79702 | Oil & Gas Operator | Apr 2025 |
| 2058 | Condor Petroleum | | Oil & Gas Operator | Nov 1990 |
| 2059 | Condor Petroleum Corporation | | Oil & Gas Operator | Aug 2020 |
| 2060 | Condor Petroleum, Inc. | Denver, CO 80202 | Oil & Gas Operator | Jun 2019 |
| 2061 | Condra, James M. Jr. | Sonora, TX 76950 | Oil & Gas Operator | May 1996 |
| 2062 | Condrin Oil 1985-A LTD | Tulsa, OK 74136 | Oil & Gas Operator | Nov 1998 |
| 2063 | Condry Oil Compa | | Oil Operator | May 1992 |
| 2064 | Cone & Petree Oil & Gas Exp. Inc | Lubbock, TX 79453 | Oil & Gas Operator | May 2024 |
| 2065 | Cone, Charles M. Services, Inc. | Dallas, TX 75372 | Oil & Gas Operator | Sep 2005 |
| 2066 | Cone, S. E. Jr. | Lubbock, TX 79408 | Oil & Gas Operator | Feb 2002 |
| 2067 | Conerty Oil & Gas Co | Chicora, PA 16025-1823 | Oil & Gas Operator | Dec 2009 |
| 2068 | Confed Oil Incorporated | Tulsa, OK 74103 | Oil & Gas Operator | Mar 2008 |
| 2069 | Confederate Bay LLC | Okemah, OK 74859 | Oil & Gas Operator | Jan 2025 |
| 2070 | Confederate Spooling Inc | Okemah, OK 74859-2409 | Oil & Gas Operator | Apr 2020 |
| 2071 | Conklin Robert L Dba Conklin Oil LLC | Tulsa, OK 74153 | Oil Operator | Jan 2025 |
| 2072 | Conklin, Patrick J. | Rushville, NY 14544 | Gas Operator | Dec 2023 |
| 2073 | Conley Energy Co LLC | Marietta, OH 45750 | Oil & Gas Operator | Dec 2020 |
| 2074 | Conley Oil Co | Pawhuska, OK 74056 | Oil Operator | Aug 2000 |
| 2075 | Conley Oil, Inc | Salyersville, KY 41465 | Oil & Gas Operator | Dec 2022 |
| 2076 | Conley P Smith Operating Co. | | Oil & Gas Operator | Jun 1995 |
| 2077 | Conley, Harry | Colony, KS 66015 | Oil Operator | Nov 2024 |
| 2078 | Conn Energy Group, LLC | | Oil & Gas Operator | Apr 2024 |
| 2079 | Conn-Okla Producing Co Inc | | Oil & Gas Operator | Nov 1992 |
| 2080 | Connaway Oil & Gas Co. | Brookesmith, TX 76827 | Oil & Gas Operator | Feb 2016 |
| 2081 | Connell, Mark Allen | Claflin, KS 67525 | Oil Operator | Dec 2024 |
| 2082 | Conner Family Limited Partnership | Humble, TX 77338 | Oil & Gas Operator | Jan 2025 |
| 2083 | Conner Jelly | Seminole, OK 74868 | Oil & Gas Operator | Mar 1996 |
| 2084 | Conner Production Co LLC | Seminole, OK 74868 | Oil & Gas Operator | Jan 2025 |
| 2085 | Conner, E B Jr | | Oil & Gas Operator | Dec 2023 |
| 2086 | Conner, Eugene | Bartlesville, OK 74005 | Oil & Gas Operator | Jul 2020 |
| 2087 | Conner, Rick | Winfield, KS 67156 | Oil Operator | Aug 2019 |
| 2088 | Conner-Marrs Company | Tulsa, OK 74105 | Oil & Gas Operator | Apr 2025 |
| 2089 | Connie J & Ronald L Yeany | Fairmount City, PA 16224-1903 | Gas Operator | Dec 2024 |
| 2090 | Connoil LLC | Grove City, OH 43123 | Oil & Gas Operator | Dec 2024 |
| 2091 | Conoco Inc. | Houston, TX 77252 | Oil & Gas Operator | Mar 2015 |
| 2092 | Conoco Incorpora | | Oil & Gas Operator | Apr 1988 |
| 2093 | ConocoPhillips Alaska, Inc. | | Oil & Gas Operator | Mar 2025 |
| 2094 | ConocoPhillips Company | Midland, TX 79701 | Oil & Gas Operator | Apr 2025 |
| 2095 | Conquest Energy, Inc. | Fort Worth, TX 76116 | Oil & Gas Operator | Apr 2025 |
| 2096 | Conquest Exploration | Houston, TX 77068 | Oil & Gas Operator | May 1991 |
| 2097 | Conquest Exploration Co. | | Oil & Gas Operator | Mar 1992 |
| 2098 | Conquest Oil Company | Big Spring, TX 79721 | Oil & Gas Operator | Aug 2024 |
| 2099 | Conquest Petroleum Inc | | Oil & Gas Operator | Nov 2014 |
| 2100 | Conquistador Petroleum,Inc. | Coleman, TX 76834 | Oil & Gas Operator | Apr 2025 |