| 101 | Cibolo Energy Operating, Inc. | Bulverde, TX 78163 | Oil & Gas Operator | Feb 2026 |
| 102 | Cimarex Energy Co | Midland, TX 79706 | Oil & Gas Operator | Feb 2026 |
| 103 | Cities Service Oil & Gas Corp | | Oil & Gas Operator | Mar 1988 |
| 104 | CNG Producing Company | New Orleans, LA 70112 | Oil & Gas Operator | Dec 2015 |
| 105 | Coastal Production Inc. | | Oil & Gas Operator | Aug 2000 |
| 106 | Cody Energy LLC | Houston, TX 77024 | Oil & Gas Operator | Jun 2020 |
| 107 | Cody Energy, Inc. | Houston, TX 77077 | Oil & Gas Operator | Dec 2025 |
| 108 | Columbia Gas Dev. Corp. | | Oil & Gas Operator | Apr 1996 |
| 109 | Concord Resources, LLC | | Oil & Gas Operator | Nov 2000 |
| 110 | Conley P Smith Operating Co. | | Oil & Gas Operator | Jun 1995 |
| 111 | Conoco Inc | Houston, TX 77252 | Oil & Gas Operator | Mar 2015 |
| 112 | Consolidated Energy Res., Inc. | | Oil Operator | Jun 1992 |
| 113 | Continental Operating Co. | Houston, TX 77024 | Oil & Gas Operator | Feb 2026 |
| 114 | Continental Resources, Inc. | Oklahoma City, OK 73126 | Oil & Gas Operator | Feb 2026 |
| 115 | Contour Energy E & P, Inc. | Houston, TX 77002 | Oil & Gas Operator | Oct 2002 |
| 116 | Contour Energy E & P, LLC | Tulsa, OK 74103 | Oil & Gas Operator | Aug 2003 |
| 117 | Cornell Oil Company | | Oil & Gas Operator | May 1985 |
| 118 | Coronado Energy E&P Company, LLC | Houston, TX 77252 | Oil & Gas Operator | Dec 2010 |
| 119 | Costilla Petroleum Corporation | Midland, TX 79702 | Oil & Gas Operator | Mar 2015 |
| 120 | Cotton Petroleum Corporation | Tulsa, OK 74102 | Oil & Gas Operator | Jan 2005 |
| 121 | Cougar Exploration, Inc. | | Oil & Gas Operator | Jun 1988 |
| 122 | Cox Oil & Gas Inc | Dallas, TX 75201 | Oil & Gas Operator | Mar 2014 |
| 123 | Crosstex Lig, LLC | | Oil Operator | Mar 2014 |
| 124 | Crosstex Processing SVCS, LLC | | Oil Operator | Mar 2014 |
| 125 | Crystal Oil And Land Company | | Oil & Gas Operator | May 1992 |
| 126 | Cxy Energy, Inc. | Dallas, TX 75251 | Oil & Gas Operator | Nov 2000 |
| 127 | Cymri Corporation, The | Houston, TX 77057 | Oil & Gas Operator | Mar 2008 |
| 128 | Cypress Gas Pipeline Company | | Oil Operator | Dec 1998 |
| 129 | Cypress Gas Pipeline, LLC | | Oil Operator | Sep 2019 |
| 130 | Cypress Production, Inc. | Azle, TX 76020 | Oil & Gas Operator | Feb 2026 |
| 131 | Dailey Oil And Gas LLC | | Oil & Gas Operator | Jun 2019 |
| 132 | Dalen Resources Oil & Gas Co | Dallas, TX 75206 | Oil & Gas Operator | Jun 2010 |
| 133 | Damson Oil Corporation | Houston, TX 77210 | Oil & Gas Operator | Mar 2005 |
| 134 | Dant Operating Company Inc. | | Oil & Gas Operator | Jan 1989 |
| 135 | Davis Petroleum Corp. | Houston, TX 77027 | Oil & Gas Operator | Feb 2026 |
| 136 | Daylight Petroleum LLC | Houston, TX 77052 | Oil & Gas Operator | Feb 2026 |
| 137 | DBL DRLG.&Prod. Services, Inc. | | Oil & Gas Operator | Jul 1997 |
| 138 | Deck Oil Company | Tulsa, OK 74101 | Oil & Gas Operator | Jun 2020 |
| 139 | Delta Development Co. Inc. | | Oil & Gas Operator | Dec 1988 |
| 140 | Delta Petroleum Corp Of Co | | Oil & Gas Operator | Oct 2010 |
| 141 | Denbury Management, Inc. | Dallas, TX 75252 | Oil & Gas Operator | Dec 1999 |
| 142 | Denbury Onshore, LLC | Plano, TX 75024 | Oil & Gas Operator | Feb 2026 |
| 143 | Denbury Resources Inc. | Plano, TX 75024 | Oil & Gas Operator | Dec 2003 |
| 144 | Denovo Oil & Gas, Inc. | Houston, TX 77210 | Oil & Gas Operator | May 1995 |
| 145 | Despot Exploration, Inc. | | Oil & Gas Operator | Apr 1990 |
| 146 | Destin Operating Company, Inc. | | Oil & Gas Operator | Jan 2023 |
| 147 | Devon Corporation | | Oil Operator | Oct 1981 |
| 148 | Devon Energy Corp (Nevada) | Oklahoma City, OK 73102 | Oil & Gas Operator | Feb 2017 |
| 149 | Devon Energy Corporation | Oklahoma City, OK 73102 | Oil & Gas Operator | Dec 2009 |
| 150 | Devon Energy Production Company, L.P. | Oklahoma City, OK 73102 | Oil & Gas Operator | Feb 2026 |
| 151 | Diamond S Operating Co. | | Oil & Gas Operator | Oct 1992 |
| 152 | Diamond Shamrock Corp | Amarillo, TX 79105 | Oil & Gas Operator | Jan 1987 |
| 153 | Diamond Shamrock Expl. Co. | | Oil & Gas Operator | Jun 1987 |
| 154 | Diasu Oil & Gas Co., Inc. | Houston, TX 77002 | Oil & Gas Operator | Mar 2016 |
| 155 | Diversified Energy Investments | | Oil & Gas Operator | May 2009 |
| 156 | Dominion Exploration & Production Inc | Houston, TX 77060 | Oil & Gas Operator | Apr 2015 |
| 157 | Dow Chemical Co. | | Oil & Gas Operator | Dec 1997 |
| 158 | Dow Intrastate Gas Company | | Oil Operator | Dec 2023 |
| 159 | Drew Cornell, Inc.-Agent | | Oil & Gas Operator | Sep 1990 |
| 160 | Drilling, Operg & Explor, Inc. | | Oil & Gas Operator | Feb 1990 |
| 161 | Dune Operating Company | Dallas, TX 75201 | Oil & Gas Operator | Jun 2016 |
| 162 | Dunhill Expl. & Prod., LLC | | Oil & Gas Operator | Nov 2004 |
| 163 | Dunhill Resources, Inc. | | Oil & Gas Operator | Nov 2005 |
| 164 | Dunn Exploration Company, LLC | | Oil & Gas Operator | Jan 2025 |
| 165 | Dynamic Exploration PTRS, LLC | | Oil & Gas Operator | Nov 2024 |
| 166 | Dynamic Exploration, Inc. | | Oil & Gas Operator | Oct 2003 |
| 167 | E & E Production Company, Inc. | | Oil & Gas Operator | Dec 2004 |
| 168 | Eason Oil Company | Oklahoma City, OK 73112 | Oil & Gas Operator | Mar 2012 |
| 169 | Eclipse Petroleum Corporation | La Grange, TX 78945 | Oil & Gas Operator | Aug 2003 |
| 170 | Ed I. Estis | | Oil & Gas Operator | Sep 1998 |
| 171 | Edward Oil Company | Youngsville, PA 16371 | Oil & Gas Operator | Nov 2024 |
| 172 | Edwin L. Cox | | Oil & Gas Operator | May 1986 |
| 173 | Edwin L. Cox & Berry R. Cox | | Oil & Gas Operator | Jun 1986 |
| 174 | Eex Corporation | Houston, TX 77060 | Oil & Gas Operator | Feb 2000 |
| 175 | El Paso E&P Company, L.P. | Houston, TX 77002 | Oil & Gas Operator | Mar 2013 |
| 176 | El Paso Production Company | Houston, TX 77002 | Oil & Gas Operator | Mar 2016 |
| 177 | Eland Energy Inc | Dallas, TX 75248 | Oil & Gas Operator | Dec 2025 |
| 178 | Elsbury & Acker | | Oil & Gas Operator | Feb 2003 |
| 179 | Elysium Energy, L.L.C | Denver, CO 80202 | Oil & Gas Operator | Jun 2019 |
| 180 | Emerald Oil Co. | | Oil & Gas Operator | Apr 1980 |
| 181 | Energy Development Corporation | Houston, TX 77067 | Oil & Gas Operator | Dec 2024 |
| 182 | Energy Reserves Group | Houston, TX 770563020 | Oil & Gas Operator | Apr 1996 |
| 183 | Energy Source, Inc.-Emerald | | Oil & Gas Operator | Apr 1983 |
| 184 | Energy Sources, Inc. | | Oil & Gas Operator | Nov 1990 |
| 185 | Energy Xxi Onshore, LLC | | Oil & Gas Operator | Dec 2023 |
| 186 | Energyquest II, LLC | The Woodlands, TX 77381 | Oil & Gas Operator | Nov 2025 |
| 187 | Energyquest Management, LLC | Houston, TX 77090 | Oil & Gas Operator | Apr 2021 |
| 188 | Energyquest Operating, L.L.C. | | Oil & Gas Operator | Jun 2023 |
| 189 | Enerquest Oil & Gas LLC | Oklahoma City, OK 73114 | Oil & Gas Operator | Nov 2025 |
| 190 | Enlink Lig, LLC | | Oil Operator | Jan 2025 |
| 191 | Enserch Exploration Inc | Dallas, TX 75206 | Oil & Gas Operator | Apr 2015 |
| 192 | Enstar Petroleum Company | | Oil & Gas Operator | Aug 1985 |
| 193 | Enstar Petroleum, Inc. | | Oil & Gas Operator | Jan 1984 |
| 194 | Entex Petroleum Inc | Oklahoma City, OK 73113 | Oil & Gas Operator | Nov 1997 |
| 195 | Entex, Inc. | | Oil & Gas Operator | Dec 1984 |
| 196 | Equinox Oil Company Inc | Plainville, KS 67663 | Oil & Gas Operator | Dec 2019 |
| 197 | Ereunao Oil & Gas, Inc. | | Oil & Gas Operator | Mar 2003 |
| 198 | Erskine Energy, LLC | H SPG NTL PK, AR 71909 | Oil & Gas Operator | Feb 2026 |
| 199 | Est. Of H. L. Hunt | | Oil & Gas Operator | Jun 1983 |
| 200 | Ethyl-Buchanan | | Oil & Gas Operator | Feb 1987 |