| 101 | Cody Energy, Inc. | Houston, TX 77077 | Oil & Gas Operator | Oct 2025 |
| 102 | Columbia Gas Dev. Corp. | | Oil & Gas Operator | Apr 1996 |
| 103 | Columbia Gulf Transmission Company, LLC | | Oil Operator | Jan 2025 |
| 104 | Columbia Minerals Corp., Inc. | | Oil & Gas Operator | May 1996 |
| 105 | Commerce Energy, Inc. | | Oil & Gas Operator | Dec 1999 |
| 106 | Compadres, Inc. | | Oil & Gas Operator | Dec 1988 |
| 107 | Comstock Oil & Gas -- La, Inc. | | Oil & Gas Operator | Mar 2005 |
| 108 | Condor Petroleum Corporation | | Oil & Gas Operator | Aug 2020 |
| 109 | Conoco Inc | Houston, TX 77252 | Oil & Gas Operator | Mar 2015 |
| 110 | ConocoPhillips Company | Midland, TX 79701 | Oil & Gas Operator | Dec 2025 |
| 111 | Consolidated Resources, Inc. | | Oil & Gas Operator | May 2004 |
| 112 | Corpus Christi Oil & Gas Co. | | Oil & Gas Operator | Dec 1991 |
| 113 | Cotton Petroleum Corporation | Tulsa, OK 74102 | Oil & Gas Operator | Jan 2005 |
| 114 | Covey Energy, Inc. | | Oil & Gas Operator | Jun 1998 |
| 115 | Cox Operating, L.L.C. | | Oil & Gas Operator | Jan 2024 |
| 116 | Crawford Hughes Operating Co. | The Woodlands, TX 77380 | Oil & Gas Operator | Dec 2025 |
| 117 | Creole Operating, LLC | | Oil & Gas Operator | Dec 2024 |
| 118 | Crimson Explor Operating, Inc. | | Oil & Gas Operator | Dec 2009 |
| 119 | Curt Weaver Et Al | | Oil Operator | Apr 1982 |
| 120 | Cxy Energy, Inc. | Dallas, TX 75251 | Oil & Gas Operator | Nov 2000 |
| 121 | Cypress E & P Corporation | Leander, TX 78646 | Oil & Gas Operator | Sep 2016 |
| 122 | Cypress Production, Inc. | Azle, TX 76020 | Oil & Gas Operator | Dec 2025 |
| 123 | D & V Petroleum Corporation | | Oil & Gas Operator | May 1992 |
| 124 | Dan A. Hughes Company | | Oil & Gas Operator | Dec 2005 |
| 125 | Dan A. Hughes Company, L.P. | Beeville, TX 78104 | Oil & Gas Operator | Sep 2025 |
| 126 | Daniel Oil Company | | Oil & Gas Operator | Jan 1983 |
| 127 | Darsey Operating Corporation | | Oil & Gas Operator | Sep 1990 |
| 128 | Davis Oil Company | Denver, CO 80202 | Oil & Gas Operator | Jun 1988 |
| 129 | Davis Petroleum Corp. | Houston, TX 77027 | Oil & Gas Operator | Dec 2025 |
| 130 | Davis-Goodman-Medders | | Oil & Gas Operator | Jun 1980 |
| 131 | Daylight Petroleum LLC | Houston, TX 77052 | Oil & Gas Operator | Dec 2025 |
| 132 | Dean Enterprises, Inc. | | Oil & Gas Operator | Jun 2019 |
| 133 | Deblin Oil & Gas, Inc | | Oil & Gas Operator | Aug 1995 |
| 134 | Denbury Management, Inc. | Dallas, TX 75252 | Oil & Gas Operator | Dec 1999 |
| 135 | Denbury Onshore, LLC | Plano, TX 75024 | Oil & Gas Operator | Dec 2025 |
| 136 | Denbury Resources Inc. | Plano, TX 75024 | Oil & Gas Operator | Dec 2003 |
| 137 | Denovo Oil & Gas, Inc. | Houston, TX 77210 | Oil & Gas Operator | May 1995 |
| 138 | Desco Oil Company | Houston, TX 77056 | Oil & Gas Operator | Feb 2017 |
| 139 | Desco-Medders | | Oil & Gas Operator | Jun 1984 |
| 140 | Despot Exploration, Inc. | | Oil & Gas Operator | Apr 1990 |
| 141 | Devon Energy Production Company, L.P. | Oklahoma City, OK 73102 | Oil & Gas Operator | Dec 2025 |
| 142 | Devon Louisiana Corporation | Houston, TX 77002 | Oil & Gas Operator | Oct 2019 |
| 143 | Di Energy Inc. | Houston, TX 77067 | Oil & Gas Operator | Jan 2004 |
| 144 | Diamond Shamrock Expl. Co. | | Oil & Gas Operator | Jun 1987 |
| 145 | Diasu Oil & Gas Co., Inc. | Houston, TX 77002 | Oil & Gas Operator | Mar 2016 |
| 146 | DMS Oil Company | Houston, TX 77042 | Oil & Gas Operator | Sep 2025 |
| 147 | Dome De Sel LLC | | Oil & Gas Operator | Nov 2024 |
| 148 | Dore-Dyn Production Co., Inc. | | Oil & Gas Operator | Jul 1993 |
| 149 | Dow Chemical Co. | | Oil & Gas Operator | Dec 1997 |
| 150 | Duer Wagner & Company | Fort Worth, TX 76102 | Oil & Gas Operator | Dec 1998 |
| 151 | Duncan Oil Inc | Denver, CO 80210 | Oil & Gas Operator | Jun 2016 |
| 152 | Dundee Petroleum, Inc. | Buffalo Gap, TX 79508 | Oil & Gas Operator | Aug 2003 |
| 153 | Dune Operating Company | Dallas, TX 75201 | Oil & Gas Operator | Jun 2016 |
| 154 | Dunhill Resources, Inc. | | Oil & Gas Operator | Nov 2005 |
| 155 | Dynamic Exploration PTRS, LLC | | Oil & Gas Operator | Nov 2024 |
| 156 | Dynamic Exploration, Inc. | | Oil & Gas Operator | Oct 2003 |
| 157 | Dynamic Offshore Resources, LLC | Houston, TX 77042 | Oil & Gas Operator | Dec 2025 |
| 158 | Ed I. Estis | | Oil & Gas Operator | Sep 1998 |
| 159 | Edwin L. Cox | | Oil & Gas Operator | May 1986 |
| 160 | El Paso E&P Company, L.P. | Houston, TX 77002 | Oil & Gas Operator | Mar 2013 |
| 161 | El Paso Production Company | Houston, TX 77002 | Oil & Gas Operator | Mar 2016 |
| 162 | Eland Energy Inc | Dallas, TX 75248 | Oil & Gas Operator | Sep 2025 |
| 163 | Elliott Oil & Gas Company | The Woodlands, TX 77380 | Oil & Gas Operator | Sep 2006 |
| 164 | Elysium Energy, L.L.C | Denver, CO 80202 | Oil & Gas Operator | Jun 2019 |
| 165 | Elysium Jennings, LLC | | Oil & Gas Operator | Dec 2024 |
| 166 | Empire Land Corporation | New Orleans, LA 70130 | Oil & Gas Operator | Nov 2014 |
| 167 | Energen Resources Maq Inc | Birmingham, AL 35203 | Oil & Gas Operator | Sep 2000 |
| 168 | Energy Development Corporation | Houston, TX 77067 | Oil & Gas Operator | Dec 2024 |
| 169 | Energy Partners, LTD. | New Orleans, LA 70170 | Oil & Gas Operator | Aug 2012 |
| 170 | Energy Properties Inc. | | Oil & Gas Operator | Dec 2023 |
| 171 | Energy Reserves Group | Houston, TX 770563020 | Oil & Gas Operator | Apr 1996 |
| 172 | Energy Xxi Onshore, LLC | | Oil & Gas Operator | Dec 2023 |
| 173 | Energyquest II, LLC | The Woodlands, TX 77381 | Oil & Gas Operator | Aug 2025 |
| 174 | Energyquest Management, LLC | Houston, TX 77090 | Oil & Gas Operator | Apr 2021 |
| 175 | Energyquest Operating, L.L.C. | | Oil & Gas Operator | Jun 2023 |
| 176 | Ensource Inc | Midland, TX 79705 | Oil & Gas Operator | Aug 1998 |
| 177 | Enstar Petroleum Company | | Oil & Gas Operator | Aug 1985 |
| 178 | Enstar Petroleum Inc | | Oil & Gas Operator | Apr 1985 |
| 179 | Epoch Petroleum Corporation | | Oil & Gas Operator | Dec 1992 |
| 180 | Equinox Oil Company Inc | Plainville, KS 67663 | Oil & Gas Operator | Dec 2019 |
| 181 | Erskine Energy, LLC | H SPG NTL PK, AR 71909 | Oil & Gas Operator | Dec 2025 |
| 182 | Est Of WM G Helis (A Partnership) | | Oil & Gas Operator | Dec 2009 |
| 183 | Etc Oil Corp | | Oil & Gas Operator | Mar 1994 |
| 184 | Exchange Oil & Gas Corporation | Tulsa, OK 74103 | Oil & Gas Operator | Oct 1987 |
| 185 | Exco Resources Inc | Dallas, TX 75251 | Oil & Gas Operator | Aug 2025 |
| 186 | Exoro Energy, L.L.C. | | Oil & Gas Operator | Jun 2021 |
| 187 | Exxon Corporation | Houston, TX 77210 | Oil & Gas Operator | Jun 2024 |
| 188 | Exxon Mobil Corporation | Spring, TX 77389 | Oil & Gas Operator | Dec 2025 |
| 189 | Famcor Oil, Inc. | Scottsdale, AZ 85260 | Oil & Gas Operator | Sep 2020 |
| 190 | Fieldwood Energy LLC | Houston, TX 77042 | Oil & Gas Operator | Dec 2024 |
| 191 | Fieldwood Energy Offshore LLC | Houston, TX 77042 | Oil & Gas Operator | Dec 2025 |
| 192 | Fina Oil And Chemical Company | Dallas, TX 75221 | Oil & Gas Operator | May 2019 |
| 193 | First Energy Corporation | | Oil & Gas Operator | Jun 1993 |
| 194 | Five-Jab, Inc. | Tomball, TX 77377 | Oil & Gas Operator | Dec 2025 |
| 195 | Flash Gas & Oil Northeast, Inc | | Oil & Gas Operator | May 2007 |
| 196 | Florida Exploration Co | Aurora, CO 80014 | Oil & Gas Operator | Sep 1989 |
| 197 | FMP Operating Company, LTD PTN | | Oil & Gas Operator | Mar 1990 |
| 198 | Forest Oil Corporation | Houston, TX 77002 | Oil & Gas Operator | Mar 2015 |
| 199 | Forman Petroleum Corporation | | Oil & Gas Operator | Aug 2001 |
| 200 | Fortuna Energy Corporation | Oklahoma City, OK 73102 | Oil & Gas Operator | Feb 2014 |