| 101 | Chaparral Energy, L.L.C. | Oklahoma City, OK 73142 | Oil & Gas Operator | Oct 2025 |
| 102 | Chaparral Natural Resources,Inc. | Austin, TX 78746 | Oil & Gas Operator | Oct 2025 |
| 103 | Charolais Energy, LLC | Kilgore, TX 75663 | Oil & Gas Operator | Oct 2025 |
| 104 | Chesapeake Operating, Inc. | Oklahoma City, OK 73154 | Oil & Gas Operator | Jun 2025 |
| 105 | Chevron Midcontinent, L.P. | Midland, TX 79706 | Oil & Gas Operator | Oct 2025 |
| 106 | Chevron USA Inc | Midland, TX 79706 | Oil & Gas Operator | Oct 2025 |
| 107 | Choice Exploration, Inc. | Irving, TX 75063 | Oil & Gas Operator | Oct 2025 |
| 108 | Christeve Oil Company, Inc. | Houston, TX 77068 | Oil & Gas Operator | Dec 2022 |
| 109 | Cico Oil & Gas Company | Houston, TX 77057 | Oil & Gas Operator | Aug 2019 |
| 110 | Cimarex Energy Co. | Midland, TX 79706 | Oil & Gas Operator | Oct 2025 |
| 111 | Cimarex Energy Co. Of Colorado | Midland, TX 79706 | Oil & Gas Operator | Oct 2025 |
| 112 | Cimarron Engineering, LLC | Kingsville, TX 78364 | Oil & Gas Operator | Oct 2025 |
| 113 | Clay Exploration, Inc. | Spring, TX 77387 | Oil & Gas Operator | Jun 2019 |
| 114 | Cliffwood Production Co. | Houston, TX 77090 | Oil & Gas Operator | Aug 2013 |
| 115 | Coastal Investments Inc. | El Campo, TX 77437 | Oil & Gas Operator | Oct 2025 |
| 116 | Coastal Oil & Gas Corporation | Houston, TX 77252 | Oil & Gas Operator | Dec 2009 |
| 117 | Coastal Plains Energy Inc | Oklahoma City, OK 73112 | Oil & Gas Operator | Oct 2025 |
| 118 | Coastal Production Company, Inc. | El Campo, TX 77437 | Oil & Gas Operator | Aug 1995 |
| 119 | Coastline Exploration, Inc. | Stafford, TX 77477 | Oil & Gas Operator | Oct 2025 |
| 120 | Cobra Oil & Gas Corporation | Wichita Falls, TX 76307 | Oil & Gas Operator | Oct 2025 |
| 121 | Coho Resources Inc. | Dallas, TX 75240 | Oil & Gas Operator | Jul 2002 |
| 122 | Cologne Production Company | San Antonio, TX 78209 | Oil & Gas Operator | Nov 2014 |
| 123 | Colt Resources Corporation | Billings, MT 59103 | Oil & Gas Operator | Feb 2013 |
| 124 | Columbia Gas Development Corp. | Houston, TX 77251 | Oil & Gas Operator | Jun 1996 |
| 125 | Comstock Oil & Gas, Inc. | Frisco, TX 75034 | Oil & Gas Operator | Dec 2012 |
| 126 | Contango Operators, Inc. | Houston, TX 77098 | Oil & Gas Operator | Dec 2022 |
| 127 | Contango Resources LLC | Andrews, TX 79714 | Oil & Gas Operator | Oct 2025 |
| 128 | Contango Resources, Inc. | Houston, TX 77002 | Oil & Gas Operator | Aug 2025 |
| 129 | Convest Energy Corporation | Houston, TX 77057 | Oil & Gas Operator | Sep 2014 |
| 130 | Coronado Energy E&P Company, LLC | Houston, TX 77252 | Oil & Gas Operator | Dec 2010 |
| 131 | Coronado Minerals, LLC | Houston, TX 77208 | Oil & Gas Operator | Oct 2025 |
| 132 | Cory, Kenneth W. | Bellaire, TX 77401 | Oil & Gas Operator | Mar 2012 |
| 133 | Cory, Kenneth W. LTD. | Bellaire, TX 77401 | Oil & Gas Operator | Oct 2025 |
| 134 | Costilla Energy Inc | Midland, TX 79702 | Oil & Gas Operator | Mar 2008 |
| 135 | Costilla Petroleum Corporation | Midland, TX 79702 | Oil & Gas Operator | Mar 2015 |
| 136 | Cox & Perkins Exploration, Inc. | Houston, TX 77057 | Oil & Gas Operator | Oct 2025 |
| 137 | Cox Resources Corporation | Dallas, TX 75244 | Oil & Gas Operator | Mar 2015 |
| 138 | Crawford Hughes Operating Co. | The Woodlands, TX 77380 | Oil & Gas Operator | Oct 2025 |
| 139 | CRD Operating, LLC | Fort Worth, TX 76116 | Oil & Gas Operator | Feb 2021 |
| 140 | Crimson Exploration Oper., Inc. | Houston, TX 77002 | Oil & Gas Operator | Dec 2019 |
| 141 | Crossroads Energy L.P. | Houston, TX 77064 | Oil & Gas Operator | Jun 2011 |
| 142 | CXL Energy LLC | Canada, 00100 | Oil & Gas Operator | Oct 2025 |
| 143 | Cypress E & P Corporation | Leander, TX 78646 | Oil & Gas Operator | Sep 2016 |
| 144 | D-Mil Production Inc | Argyle, TX 76226 | Oil & Gas Operator | Oct 2025 |
| 145 | Dale Operating Company | Dallas, TX 75201 | Oil & Gas Operator | Oct 2025 |
| 146 | Dalen Resources Oil & Gas Co. | Dallas, TX 75206 | Oil & Gas Operator | Jun 2010 |
| 147 | Dartex Energy Corporation | Austin, TX 78746 | Oil & Gas Operator | Oct 2025 |
| 148 | Daystar Operating Company, LLC | Austin, TX 78750 | Oil & Gas Operator | Apr 2008 |
| 149 | DCP Operating Co LP | Houston, TX 77042 | Oil & Gas Operator | May 2025 |
| 150 | Dedica Energy Corporation | Mattoon, IL 61938 | Oil & Gas Operator | Mar 2008 |
| 151 | Delaware Davis Petroleum Corp. | Houston, TX 77056 | Oil & Gas Operator | Jan 2000 |
| 152 | Denali Oil & Gas Management, LLC | Houston, TX 77060 | Oil & Gas Operator | Dec 2012 |
| 153 | Devon Energy Corp (Nevada) | Oklahoma City, OK 73102 | Oil & Gas Operator | Feb 2017 |
| 154 | Devon Energy Operating Co., L.P. | Oklahoma City, OK 73102 | Oil & Gas Operator | Jun 2009 |
| 155 | Devon Energy Production Company LP | Oklahoma City, OK 73102 | Oil & Gas Operator | Oct 2025 |
| 156 | Dewbre Petroleum Corporation | Corpus Chrsti, TX 78404 | Oil & Gas Operator | Oct 2025 |
| 157 | Diamond Operating, LLC | Wichita Falls, TX 76308 | Oil & Gas Operator | Aug 2010 |
| 158 | DJ Exploration, Inc. | San Antonio, TX 78257 | Oil & Gas Operator | Oct 2025 |
| 159 | Dominion Minerals Corporation | Houston, TX 77014 | Oil & Gas Operator | Nov 2009 |
| 160 | Dominion Oklahoma Texas E&P, Inc | Richmond, VA 23219 | Oil & Gas Operator | Sep 2018 |
| 161 | Dorado Oil Company | Corpus Chrsti, TX 78403 | Oil & Gas Operator | Oct 2013 |
| 162 | Double Play Oil & Gas, Inc | Portland, TX 78374 | Oil & Gas Operator | Oct 2025 |
| 163 | Dreyfus, Louis Natural Gas Corp | Oklahoma City, OK 73134 | Oil & Gas Operator | Nov 2001 |
| 164 | Dynamic Production, Inc. | Fort Worth, TX 76106 | Oil & Gas Operator | Oct 2025 |
| 165 | Eagle Ford Hunter Resources,Inc. | Houston, TX 77024 | Oil & Gas Operator | Apr 2013 |
| 166 | Earthstone Operating, LLC | The Woodlands, TX 77380 | Oil & Gas Operator | Jul 2025 |
| 167 | Eei Operating Inc. | Plano, TX 75093 | Oil & Gas Operator | May 2015 |
| 168 | Eex Corporation | Houston, TX 77060 | Oil & Gas Operator | Feb 2000 |
| 169 | Eex E&P Company, L.P. | Houston, TX 77060 | Oil & Gas Operator | Jul 2003 |
| 170 | Eex Operating, L.P. | Houston, TX 77060 | Oil & Gas Operator | Jul 2003 |
| 171 | El Paso E&P Company, L.P. | Houston, TX 77002 | Oil & Gas Operator | Mar 2013 |
| 172 | El Paso Production Oil & Gas Co. | Houston, TX 77252 | Oil & Gas Operator | Oct 2025 |
| 173 | Ellstrom Energy Company | Kingwood, TX 77339 | Oil & Gas Operator | Nov 2000 |
| 174 | Ellsworth, H. P. O&G Properties | Corpus Chrsti, TX 78413 | Oil & Gas Operator | Oct 2025 |
| 175 | Encana Oil & Gas (USA) Inc. | Denver, CO 80202 | Oil & Gas Operator | Oct 2020 |
| 176 | Energy Development Corporation | Houston, TX 77067 | Oil & Gas Operator | Dec 2024 |
| 177 | Energy Transfer Crude Marketing LLC | Dallas, TX 75225 | Oil Operator | May 2025 |
| 178 | Enerquest Oil & Gas LLC | Oklahoma City, OK 73114 | Oil & Gas Operator | Jun 2025 |
| 179 | Enserch Exploration Inc | Dallas, TX 75206 | Oil & Gas Operator | Apr 2015 |
| 180 | EOG Resources, Inc. | Midland, TX 79702 | Oil & Gas Operator | Oct 2025 |
| 181 | EP Energy E&P Company, LP | Houston, TX 77210 | Oil & Gas Operator | Jan 2023 |
| 182 | EP Operating Limited Partnership | Dallas, TX 75201 | Oil & Gas Operator | Feb 1995 |
| 183 | Escondido Petroleum Company, Inc | Houston, TX 77063 | Oil & Gas Operator | Oct 2025 |
| 184 | Esenjay Petroleum Corp. | Corpus Chrsti, TX 78471 | Oil & Gas Operator | Jul 1998 |
| 185 | Etc Texas Pipeline, LTD. | Dallas, TX 75225 | Oil Operator | Sep 2023 |
| 186 | European-Southwest Co. | Houston, TX 77254 | Oil & Gas Operator | Oct 2025 |
| 187 | Evans, Julian | Houston, TX 77024 | Oil & Gas Operator | Nov 1995 |
| 188 | Everest Minerals Corp. | Corpus Chrsti, TX 78403 | Oil & Gas Operator | Apr 2001 |
| 189 | Everest Resource Company | Corpus Chrsti, TX 78403 | Oil & Gas Operator | Oct 2025 |
| 190 | Express Oil Co. | Hallettsville, TX 77964 | Oil & Gas Operator | Oct 2025 |
| 191 | Exxon Corporation | Houston, TX 77210 | Oil & Gas Operator | Jun 2024 |
| 192 | Ffa Petroleum Services | Victoria, TX 77903 | Oil & Gas Operator | Sep 2001 |
| 193 | Fieldwood Onshore LLC | Houston, TX 77098 | Oil & Gas Operator | Oct 2025 |
| 194 | Fina Oil And Chemical Company | Dallas, TX 75221 | Oil & Gas Operator | May 2019 |
| 195 | Finaly Resources LLC | Sunset Beach, CA 90742 | Oil & Gas Operator | Oct 2025 |
| 196 | First Aransas Reserves, Inc. | Alvin, TX 77511 | Oil & Gas Operator | Mar 2018 |
| 197 | Firstrike Energy Corporation | Cleburne, TX 76033 | Oil & Gas Operator | Jan 2025 |
| 198 | Fletcher Operating, LLC | Fairhope, AL 36532 | Oil & Gas Operator | Oct 2025 |
| 199 | Forest Oil Corporation | Houston, TX 77002 | Oil & Gas Operator | Mar 2015 |
| 200 | Forza Operating, LLC | The Woodlands, TX 77380 | Oil & Gas Operator | Oct 2025 |