| 2001 | Conley, Harry | Colony, KS 66015 | Oil Operator | Nov 2025 |
| 2002 | Conley, John | | Oil Operator | Aug 2000 |
| 2003 | Conn Energy Group, LLC | | Oil & Gas Operator | Apr 2024 |
| 2004 | Conn-Okla Producing Co Inc | | Oil & Gas Operator | Nov 1992 |
| 2005 | Connaway Oil & Gas Co. | Brookesmith, TX 76827 | Oil & Gas Operator | Feb 2016 |
| 2006 | Connell, Mark Allen | Claflin, KS 67525 | Oil Operator | Dec 2025 |
| 2007 | Conner Jelly | Seminole, OK 74868 | Oil & Gas Operator | Mar 1996 |
| 2008 | Conner Production Co LLC | Seminole, OK 74868 | Oil & Gas Operator | Feb 2026 |
| 2009 | Conner, E B Jr | | Oil & Gas Operator | Dec 2023 |
| 2010 | Conner, Eugene | Bartlesville, OK 74005 | Oil & Gas Operator | Jul 2020 |
| 2011 | Conner, Rick | Winfield, KS 67156 | Oil Operator | Aug 2019 |
| 2012 | Conner-Marrs Company | Tulsa, OK 74105 | Oil & Gas Operator | Apr 2026 |
| 2013 | Connie J & Ronald L Yeany | Fairmount City, PA 16224-1903 | Gas Operator | Dec 2025 |
| 2014 | Connoil LLC | Grove City, OH 43123 | Oil & Gas Operator | Dec 2025 |
| 2015 | Conoco Inc | Houston, TX 77252 | Oil & Gas Operator | Mar 2015 |
| 2016 | Conoco Incorpora | | Oil & Gas Operator | Apr 1988 |
| 2017 | ConocoPhillips Alaska, Inc. | | Oil & Gas Operator | Feb 2026 |
| 2018 | ConocoPhillips Company | Midland, TX 79701 | Oil & Gas Operator | Apr 2026 |
| 2019 | Conquest Energy, Inc. | Fort Worth, TX 76116 | Oil & Gas Operator | Apr 2026 |
| 2020 | Conquest Exploration | Houston, TX 77068 | Oil & Gas Operator | May 1991 |
| 2021 | Conquest Exploration Co. | | Oil & Gas Operator | Mar 1992 |
| 2022 | Conquest Oil Company | Big Spring, TX 79721 | Oil & Gas Operator | Aug 2024 |
| 2023 | Conquest Petroleum Inc | | Oil & Gas Operator | Nov 2014 |
| 2024 | Conquistador Petroleum,Inc. | Coleman, TX 76834 | Oil & Gas Operator | Apr 2026 |
| 2025 | Conrade Patsy | | Oil Operator | Jan 1986 |
| 2026 | Cons Asset MGMT SVCS E&P Op, LLC | Houston, TX 77002 | Oil Operator | Dec 2017 |
| 2027 | Considine, Barry | Burrton, KS 67020 | Gas Operator | Mar 2025 |
| 2028 | Consol Gas Company | Canonsburg, PA 15317 | Oil & Gas Operator | Dec 2021 |
| 2029 | Consolidated Energy Inv., Inc. | | Oil & Gas Operator | Oct 2013 |
| 2030 | Consolidated Energy Res., Inc. | | Oil Operator | Jun 1992 |
| 2031 | Consolidated Engy Reserve Inc | | Oil & Gas Operator | Jul 1991 |
| 2032 | Consolidated Exploration Company | Nichols Hill, OK 73116 | Oil & Gas Operator | Apr 2015 |
| 2033 | Consolidated Gas & Energy Corp. | San Diego, CA 92130 | Oil Operator | Apr 2012 |
| 2034 | Consolidated Natural Res. Corp. | Kilgore, TX 75662 | Oil & Gas Operator | Jan 2016 |
| 2035 | Consolidated Oil | | Oil Operator | Jul 1996 |
| 2036 | Consolidated Oil & Gas Inc | Wichita, KS 67202 | Oil & Gas Operator | Dec 2012 |
| 2037 | Consolidated Oil Well Services, Inc | Chanute, KS 66720 | Oil Operator | Jan 2008 |
| 2038 | Consolidated Peto Equity LTD | La Crescenta, CA 91214 | Oil & Gas Operator | Dec 1996 |
| 2039 | Consolidated Petro PTNRS I, LLC | Austin, TX 78759 | Oil & Gas Operator | Mar 2003 |
| 2040 | Consolidated Petrol Corp | Columbus, OH 43215 | Oil & Gas Operator | Dec 1995 |
| 2041 | Consolidated Production Inc. | Seminole, OK 74868 | Oil & Gas Operator | Feb 2026 |
| 2042 | Consolidated Properties | Tulsa, OK 74129 | Oil & Gas Operator | Jan 2017 |
| 2043 | Consolidated Res Of Amer | Cincinnati, OH 45208 | Oil & Gas Operator | Dec 1996 |
| 2044 | Consolidated Resources Corp | Shawnee, OK 74801 | Oil & Gas Operator | Sep 2014 |
| 2045 | Consolidated Resources, Inc. | | Oil & Gas Operator | May 2004 |
| 2046 | Consolidation Coal Company | Saint Clairsville, OH 43950-8742 | Oil & Gas Operator | Dec 2020 |
| 2047 | Consortium Energy LLC | Tallmadge, OH 44278 | Oil & Gas Operator | Dec 2025 |
| 2048 | Constitution Gas Transport Co., Inc. | Salt Lake City, UT 84124-1110 | Gas Operator | Jun 2012 |
| 2049 | Constitution Investment Co LLC | Marietta, OH 45750 | Oil & Gas Operator | Dec 2024 |
| 2050 | Constitution Petroleum | Salt Lake City, UT 84124-1110 | Oil & Gas Operator | Dec 2008 |
| 2051 | Consumers Energy Co | | Oil & Gas Operator | Apr 2010 |
| 2052 | Contango Midstream Company | Houston, TX 77002-3023 | Oil & Gas Operator | Feb 2026 |
| 2053 | Contango Operators, Inc. | Houston, TX 77098 | Oil & Gas Operator | Dec 2022 |
| 2054 | Contango Operators, LLC | | Oil & Gas Operator | Nov 2024 |
| 2055 | Contango Resources Company | | Oil & Gas Operator | Mar 2009 |
| 2056 | Contango Resources LLC | Andrews, TX 79714 | Oil & Gas Operator | Apr 2026 |
| 2057 | Contango Resources, Inc. | Houston, TX 77002 | Oil & Gas Operator | Feb 2026 |
| 2058 | Contango Rocky Mountain Inc | Houston, TX 77002 | Oil & Gas Operator | Jan 2020 |
| 2059 | Continental Brok | | Oil Operator | Oct 1994 |
| 2060 | Continental Ener | | Oil & Gas Operator | Dec 1996 |
| 2061 | Continental Energy | Garden City, KS 67846-0918 | Oil & Gas Operator | Jul 2017 |
| 2062 | Continental Energy Operating LLC | Tulsa, OK 74114-1302 | Oil & Gas Operator | Feb 2026 |
| 2063 | Continental Expl | | Oil Operator | Sep 1991 |
| 2064 | Continental Exploration LLC | Richardson, TX 75080 | Oil & Gas Operator | Apr 2026 |
| 2065 | Continental Exploration, Inc. | | Oil Operator | Dec 2001 |
| 2066 | Continental Export Corporation | Bowie, TX 76230 | Oil & Gas Operator | Sep 2013 |
| 2067 | Continental Gas Inc | Enid, OK 73702-5103 | Oil & Gas Operator | Apr 2012 |
| 2068 | Continental Industries LC | Casper, WY 82602 | Oil & Gas Operator | Feb 2008 |
| 2069 | Continental Oil | | Oil Operator | Jun 1985 |
| 2070 | Continental Oil & Gas Co. Inc. | | Oil & Gas Operator | Jul 1997 |
| 2071 | Continental Oil & Refining Co | Catoosa, OK 74015-0831 | Oil & Gas Operator | Feb 2026 |
| 2072 | Continental Oil Co. | Durango, CO 81301 | Oil & Gas Operator | Dec 1983 |
| 2073 | Continental Operating Co. | Houston, TX 77024 | Oil & Gas Operator | Apr 2026 |
| 2074 | Continental Petroleum, LLC | | Oil & Gas Operator | Oct 2013 |
| 2075 | Continental Production Co LLC | Greenwood VIllage, CO 80155 | Oil & Gas Operator | Aug 2012 |
| 2076 | Continental Resources, Inc. | Oklahoma City, OK 73126 | Oil & Gas Operator | Apr 2026 |
| 2077 | Continental Trend Resources, Inc | Oklahoma City, OK 73126 | Oil & Gas Operator | Apr 2026 |
| 2078 | Continental-Emsco Co | Hobbs, NM 88241 | Oil & Gas Operator | Jun 1995 |
| 2079 | Continual Oil & Gas, Inc. | Abilene, TX 79602 | Oil & Gas Operator | Apr 2026 |
| 2080 | Continuum Midstream, LLC | Tulsa, OK 74136 | Oil Operator | Aug 2025 |
| 2081 | Contour Energy E & P, Inc. | Houston, TX 77002 | Oil & Gas Operator | Oct 2002 |
| 2082 | Contour Energy E & P, LLC | Tulsa, OK 74103 | Oil & Gas Operator | Aug 2003 |
| 2083 | Contour Expl And Prod, LLC | Dallas, TX 75204 | Oil & Gas Operator | Apr 2026 |
| 2084 | Contour Oil & Gas, LLC | Abilene, TX 79602 | Oil & Gas Operator | Dec 2015 |
| 2085 | Contract Energy, L.L.C. | Houston, TX 77057 | Oil & Gas Operator | Oct 2012 |
| 2086 | Contract Oil & Gas Service Co. | Tomball, TX 77375 | Oil & Gas Operator | Apr 2007 |
| 2087 | Contrast Energy, LLC | Tulsa, OK 74119 | Oil & Gas Operator | Apr 2026 |
| 2088 | Contreras Al Consultants Inc | Oklahoma City, OK 73113-0762 | Oil & Gas Operator | Oct 2020 |
| 2089 | Converse Oil Corp. | | Oil Operator | Dec 2010 |
| 2090 | Convert Operating, LLC | Midland, TX 79701 | Oil & Gas Operator | Dec 2019 |
| 2091 | Convest Energy Corporation | Houston, TX 77057 | Oil & Gas Operator | Sep 2014 |
| 2092 | Conway Energy Oper Services Inc. | San Diego, TX 78384 | Oil & Gas Operator | Apr 2026 |
| 2093 | Cook D L | Holliday, TX 76366 | Oil & Gas Operator | Dec 2008 |
| 2094 | Cook Energy Inc | Cooksburg, PA 16217-0054 | Oil & Gas Operator | Dec 2004 |
| 2095 | Cook Exploration Co. | Longview, TX 75602 | Oil & Gas Operator | Apr 2026 |
| 2096 | Cook Inlet Energy, LLC. | | Oil & Gas Operator | Feb 2026 |
| 2097 | Cook L D | Bartlesville, OK 74005-2306 | Oil & Gas Operator | Nov 2005 |
| 2098 | Cook Marshall Operating, Inc. | Austin, TX 78746 | Oil & Gas Operator | Mar 1995 |
| 2099 | Cook Oil Company | Wewoka, OK 74884 | Oil & Gas Operator | Sep 2015 |
| 2100 | Cook Operating C | | Oil Operator | May 1987 |