| 2001 | Energyquest II, LLC | The Woodlands, TX 77381 | Oil & Gas Operator | Jan 2025 |
| 2002 | Energyquest Management, LLC | Houston, TX 77090 | Oil & Gas Operator | Apr 2021 |
| 2003 | Enernet Inc | Oklahoma City, OK 73102-8004 | Oil & Gas Operator | Nov 2014 |
| 2004 | Enerquest Oil & Gas LLC | Oklahoma City, OK 73114 | Oil & Gas Operator | Jan 2025 |
| 2005 | Enersearch Inc | Sand Springs, OK 74063 | Oil & Gas Operator | Dec 2013 |
| 2006 | Enersource Petroleum Inc | Bixby, OK 74008 | Oil & Gas Operator | Jan 2025 |
| 2007 | Enersource Royalty Corporation | Oklahoma City, OK 73102 | Oil & Gas Operator | May 2013 |
| 2008 | Enertec Corporation | Nowata, OK 74048-0632 | Oil & Gas Operator | Sep 2018 |
| 2009 | Enervest Operating LLC | Houston, TX 77002 | Oil & Gas Operator | Apr 2025 |
| 2010 | Enervest Resources Inc | | Oil & Gas Operator | Jun 2018 |
| 2011 | Enerwest Trading Co LLC | Duncan, OK 73534 | Oil & Gas Operator | Jan 2025 |
| 2012 | Enex Resources Corporation | Houston, TX 77002 | Oil & Gas Operator | Dec 2009 |
| 2013 | Enexco, Inc. | Dallas, TX 75243 | Oil & Gas Operator | Mar 2017 |
| 2014 | England Operating LLC | Littleton, CO 80120-4529 | Oil & Gas Operator | Nov 2014 |
| 2015 | Enhanced Hydrocarbons Inc | Claremore, OK 74017 | Oil & Gas Operator | May 2013 |
| 2016 | Enlink Crude Marketing LLC | Houston, TX 77010 | Oil & Gas Operator | Aug 2022 |
| 2017 | Enloe Jenny L | Skiatook, OK 74070 | Oil Operator | Nov 1998 |
| 2018 | Enmark Gas Gathering L. P. | Dallas, TX 75252 | Oil & Gas Operator | Oct 2024 |
| 2019 | Ennex, Inc. | | Oil & Gas Operator | Oct 1993 |
| 2020 | Ennis Bill H | Sasakwa, OK 74867-0001 | Oil & Gas Operator | Sep 2014 |
| 2021 | Enogex Products Corp | Oklahoma City, OK 73124-0300 | Oil & Gas Operator | Jun 2022 |
| 2022 | Enogex Services Corporation | Oklahoma City, OK 73124-0300 | Oil & Gas Operator | Apr 2009 |
| 2023 | Enserch Exploration Inc | Dallas, TX 75206 | Oil & Gas Operator | Apr 2015 |
| 2024 | Ensight Energy Group Inc | Richardson, TX 75080-2370 | Oil & Gas Operator | Jan 2025 |
| 2025 | Ensource Inc | Midland, TX 79705 | Oil & Gas Operator | Aug 1998 |
| 2026 | Enterprise Crude Oil LLC | Oklahoma City, OK 73102 | Oil Operator | Aug 2011 |
| 2027 | Enterprise Energy Exploration Inc | Tulsa, OK 74133-6724 | Oil & Gas Operator | Feb 2025 |
| 2028 | Enterprise Energy Prod Co Inc | Tulsa, OK 74133-6754 | Oil & Gas Operator | Mar 2015 |
| 2029 | Enterprise Exploration Inc | Tulsa, OK 74133 | Oil & Gas Operator | Nov 2020 |
| 2030 | Enterprising Enterprises Inc | Tulsa, OK 74137 | Oil Operator | Jun 2009 |
| 2031 | Entex Petroleum, Inc. | Oklahoma City, OK 73113 | Oil & Gas Operator | Nov 1997 |
| 2032 | Entransco Energy LLC | Dewey, OK 74029 | Oil & Gas Operator | Oct 2024 |
| 2033 | Envirotek Fuel Systems Inc | Dallas, TX 75243 | Oil & Gas Operator | May 2013 |
| 2034 | EOG (Oklahoma) Inc. | Oklahoma City, OK 73112 | Oil & Gas Operator | Oct 2016 |
| 2035 | EOG Resources, Inc. | Midland, TX 79702 | Oil & Gas Operator | Apr 2025 |
| 2036 | Eok Operating LLC | Oklahoma City, OK 73103 | Oil & Gas Operator | Jan 2025 |
| 2037 | Eola Mud Disposal Company | Maysville, OK 73057-9402 | Oil Operator | Sep 1997 |
| 2038 | Eola Reclaimers Inc | Maysville, OK 73057 | Oil & Gas Operator | Nov 2005 |
| 2039 | Eott Energy Corporation | Oklahoma City, OK 73118 | Oil & Gas Operator | Dec 1995 |
| 2040 | Eott Energy Operating LP | Houston, TX 77210-4666 | Oil & Gas Operator | Oct 2009 |
| 2041 | EP Energy E&P Company, LP | Houston, TX 77210 | Oil & Gas Operator | May 2022 |
| 2042 | EP Operating LP | Dallas, TX 75201 | Oil & Gas Operator | Mar 2015 |
| 2043 | Epley Bobbie Inc | Wilson, OK 73463-6319 | Oil Operator | Jun 2007 |
| 2044 | Epoch Resources Of Texas Inc | Port Aransas, TX 78373-1637 | Oil & Gas Operator | Nov 2014 |
| 2045 | Epperson Dwight | Okemah, OK 74859 | Oil Operator | Jan 2013 |
| 2046 | Epperson John R | Bartlesville, OK 74003 | Oil Operator | Aug 1999 |
| 2047 | Equal Energy Us Inc | Tulsa, OK 74103-4621 | Oil & Gas Operator | Nov 2019 |
| 2048 | Equinox Oil Company | Plainville, KS 67663 | Oil & Gas Operator | Dec 2024 |
| 2049 | Equipment Lott Inc The | Hennessey, OK 73742-0655 | Oil & Gas Operator | Mar 2008 |
| 2050 | Equity Drilling Company Inc | Dewey, OK 74029 | Oil & Gas Operator | Nov 1998 |
| 2051 | Equity Export Oil & Gas Co Inc | Kansas City, MO 64116 | Oil & Gas Operator | Feb 2002 |
| 2052 | Eratz Investments Inc. | Dallas, TX 75240 | Oil & Gas Operator | Apr 2025 |
| 2053 | Ernst Petroleum Company Inc | Arlington, VA 22201 | Oil & Gas Operator | Aug 2013 |
| 2054 | Erwin Oil & Gas LLC | Pawhuska, OK 74056 | Oil & Gas Operator | Apr 2019 |
| 2055 | Erwin, James D. | Dallas, TX 75225 | Oil & Gas Operator | Nov 1993 |
| 2056 | Escher Corporation | Oklahoma City, OK 73120 | Oil & Gas Operator | Feb 2025 |
| 2057 | Esco Exploration, Inc | Dallas, TX 75201 | Oil & Gas Operator | Mar 2015 |
| 2058 | Escott Oil Inc | Nowata, OK 74048 | Oil & Gas Operator | Feb 2000 |
| 2059 | Esenjay Exploration, Inc | Houston, TX 77042 | Oil & Gas Operator | Jan 2025 |
| 2060 | Esis Inc | | Oil & Gas Operator | Feb 2017 |
| 2061 | Eskridge Oil & Supply | Tulsa, OK 74105 | Oil Operator | Aug 2014 |
| 2062 | Eskridge Production Company | Tulsa, OK 74112-1428 | Oil Operator | Sep 2019 |
| 2063 | Eslick Nancy Sue | Bristow, OK 74010-3873 | Oil Operator | Aug 2013 |
| 2064 | Esper Production Co | Arlington, TX 76011-2427 | Oil & Gas Operator | Apr 2015 |
| 2065 | Esperanza Energy Corp. | Prosper, TX 75078 | Oil & Gas Operator | Mar 2015 |
| 2066 | Essex Energy Inc | Yukon, OK 73099-5126 | Oil & Gas Operator | Apr 2014 |
| 2067 | Essman Energy, LLC | Tulsa, OK 74136 | Oil & Gas Operator | Sep 2019 |
| 2068 | Estoril Producing Corporation | Midland, TX 79701 | Oil & Gas Operator | Apr 1994 |
| 2069 | Eubank Michael Dba Trilby Oil Company | Amber, OK 73004-4903 | Oil Operator | May 2022 |
| 2070 | Eubank Operating Company | Cushing, OK 74023 | Oil & Gas Operator | Aug 2024 |
| 2071 | Eufaula Enterprises Inc | | Gas Operator | Nov 1997 |
| 2072 | Evans / Heslet Operating | Tulsa, OK 74170 | Oil & Gas Operator | Aug 1999 |
| 2073 | Evans Production Co. | Pampa, TX 79066 | Oil & Gas Operator | Sep 2020 |
| 2074 | Evergreen Drilling LLC | Edmond, OK 73083-7088 | Oil Operator | Apr 2020 |
| 2075 | Evergreen Operating Corp | Denver, CO 80202 | Oil & Gas Operator | Dec 2019 |
| 2076 | Evolution Energy LLC | Oklahoma City, OK 73116 | Oil & Gas Operator | Jan 2025 |
| 2077 | Evolution Operating Co., Inc. | Houston, TX 77079 | Oil & Gas Operator | Apr 2025 |
| 2078 | Ewsc Inc | Kenosha, WI 53142-3775 | Oil & Gas Operator | Apr 2020 |
| 2079 | Excalibur Resources LLC | Houston, TX 77002-5220 | Oil & Gas Operator | Jan 2025 |
| 2080 | Excel Operating Inc | Dallas, TX 75234-7300 | Oil & Gas Operator | Jun 2022 |
| 2081 | Excel Production Inc | Lubbock, TX 79424-2341 | Oil Operator | Apr 2020 |
| 2082 | Excelco Energy Inc. | Kingwood, TX 77339 | Oil & Gas Operator | Jul 2018 |
| 2083 | Exco Resources Inc | Dallas, TX 75251 | Oil & Gas Operator | Jan 2025 |
| 2084 | Executive Properties Inc | Amarillo, TX 79110 | Oil & Gas Operator | Aug 1994 |
| 2085 | Exok, Inc. | Oklahoma City, OK 73116 | Oil & Gas Operator | Jan 2025 |
| 2086 | Exoko Operating Company Inc | Tulsa, OK 74170-0246 | Oil & Gas Operator | Jan 2006 |
| 2087 | Explo Oil, Inc. | Dallas, TX 75251 | Oil & Gas Operator | Apr 2025 |
| 2088 | Exploration Associates | Oklahoma City, OK 73102-8606 | Oil & Gas Operator | Mar 2015 |
| 2089 | Exploration Associates II LLC | Oklahoma City, OK 73102-8815 | Oil & Gas Operator | Jan 2013 |
| 2090 | Exploration Professionals Inc | Chelsea, OK 74016-0066 | Oil Operator | Dec 2023 |
| 2091 | Exploration Technologies Inc | Crescent, OK 73028-0546 | Oil & Gas Operator | Mar 2015 |
| 2092 | Export Petroleum Corporation | Fort Worth, TX 76147 | Oil & Gas Operator | Apr 2025 |
| 2093 | Express Oil & Gas LLC | Oklahoma City, OK 73142 | Oil & Gas Operator | Jan 2025 |
| 2094 | Extex Operating Company | Houston, TX 77057 | Oil & Gas Operator | Apr 2025 |
| 2095 | Exxon Mobil Corporation | Spring, TX 77389 | Oil & Gas Operator | Apr 2025 |
| 2096 | Exxonmobil Oil Corp | Houston, TX 77210 | Oil & Gas Operator | Feb 2025 |
| 2097 | Eyler Corporation | | Oil & Gas Operator | Nov 2012 |
| 2098 | Eyler Dean E | Cleveland, OK 74020 | Oil & Gas Operator | Jan 2025 |
| 2099 | Eyler Nelson E | | Oil Operator | Nov 1998 |
| 2100 | F & G Management LLC | Claremore, OK 74019-0392 | Oil Operator | Jan 2025 |