| 101 | Cashco, L.L.C. | Houston, TX 77024 | Oil & Gas Operator | Jul 1999 |
| 102 | Caskids Operating Company | Houston, TX 77027 | Oil & Gas Operator | Oct 2025 |
| 103 | Cavalry Resources LLC | The Woodlands, TX 77380 | Oil & Gas Operator | Jun 2010 |
| 104 | Caza Operating, LLC | Midland, TX 79701 | Oil & Gas Operator | Oct 2025 |
| 105 | CBM Partners Corporation | Overland Park, KS 66221 | Oil Operator | Aug 2015 |
| 106 | CD Consulting & Operating Co. | Bridgeport, TX 76426 | Oil & Gas Operator | Oct 2025 |
| 107 | Ceniza Petroleum, Inc. | Portland, TX 78374 | Oil & Gas Operator | Oct 2025 |
| 108 | Central Gulf Petroleum Inc | The Woodlands, TX 77380 | Oil & Gas Operator | Oct 2025 |
| 109 | Century Resources, Inc. | Houston, TX 77056 | Oil & Gas Operator | Oct 2025 |
| 110 | Chaparral (USA) Energy, Inc. | Oklahoma City, OK 73114 | Oil & Gas Operator | Sep 2002 |
| 111 | Chaparral Energy, L.L.C. | Oklahoma City, OK 73142 | Oil & Gas Operator | Oct 2025 |
| 112 | Chaparral Natural Resources,Inc. | Austin, TX 78746 | Oil & Gas Operator | Oct 2025 |
| 113 | Chapman Oil Company | Midland, TX 79702 | Oil & Gas Operator | Jun 2025 |
| 114 | Charolais Energy, LLC | Kilgore, TX 75663 | Oil & Gas Operator | Oct 2025 |
| 115 | Chase Energy, Inc. | Austin, TX 78763 | Oil & Gas Operator | Oct 2001 |
| 116 | Chesapeake Operating, Inc. | Oklahoma City, OK 73154 | Oil & Gas Operator | Jun 2025 |
| 117 | Chevron Midcontinent, L.P. | Midland, TX 79706 | Oil & Gas Operator | Oct 2025 |
| 118 | Chevron USA Inc | Midland, TX 79706 | Oil & Gas Operator | Oct 2025 |
| 119 | Chief Petroleum Company | Dallas, TX 75244 | Oil & Gas Operator | Jul 1997 |
| 120 | Choice Exploration, Inc. | Irving, TX 75063 | Oil & Gas Operator | Oct 2025 |
| 121 | CHP Oil & Gas Company, L.C. | El Campo, TX 77437 | Oil & Gas Operator | Oct 2025 |
| 122 | Cico Oil & Gas Company | Houston, TX 77057 | Oil & Gas Operator | Aug 2019 |
| 123 | Cimarex Energy Co. | Midland, TX 79706 | Oil & Gas Operator | Oct 2025 |
| 124 | Cimarron Engineering Corp. | Kingsville, TX 78364 | Oil & Gas Operator | May 2015 |
| 125 | Cimarron Engineering, LLC | Kingsville, TX 78364 | Oil & Gas Operator | Oct 2025 |
| 126 | Clay Exploration, Inc. | Spring, TX 77387 | Oil & Gas Operator | Jun 2019 |
| 127 | Cliffwood Production Co. | Houston, TX 77090 | Oil & Gas Operator | Aug 2013 |
| 128 | CML Exploration, LLC | Austin, TX 78746 | Oil & Gas Operator | Oct 2025 |
| 129 | Coastal Expanse Oil & Gas | Austin, TX 78704 | Oil & Gas Operator | Oct 2025 |
| 130 | Coastal Investments Inc. | El Campo, TX 77437 | Oil & Gas Operator | Oct 2025 |
| 131 | Coastal Oil & Gas Corporation | Houston, TX 77252 | Oil & Gas Operator | Dec 2009 |
| 132 | Coastal Plains Exploration, LLC | Port Lavaca, TX 77979 | Oil & Gas Operator | Oct 2025 |
| 133 | Coastal Production Company, Inc. | El Campo, TX 77437 | Oil & Gas Operator | Aug 1995 |
| 134 | Coastline Exploration, Inc. | Stafford, TX 77477 | Oil & Gas Operator | Oct 2025 |
| 135 | Coastline Operating, L.L.C. | Houston, TX 77027 | Oil & Gas Operator | Dec 2006 |
| 136 | Cobra Oil & Gas Corporation | Wichita Falls, TX 76307 | Oil & Gas Operator | Oct 2025 |
| 137 | Cockburn Oil Corporation | Lubbock, TX 79493 | Oil & Gas Operator | Jul 2005 |
| 138 | Coleville Petroleum Company | McAllen, TX 78503 | Oil & Gas Operator | Mar 1996 |
| 139 | Cometra Oil And Gas, Inc. | Fort Worth, TX 76102 | Oil & Gas Operator | Feb 1997 |
| 140 | Conoco Inc. | Houston, TX 77252 | Oil & Gas Operator | Mar 2015 |
| 141 | Convest Energy Corporation | Houston, TX 77057 | Oil & Gas Operator | Sep 2014 |
| 142 | Core E & P Corp. | Victoria, TX 77902 | Oil & Gas Operator | Oct 2025 |
| 143 | Corum Production Company | Houston, TX 77002 | Oil & Gas Operator | Oct 2025 |
| 144 | Costilla Energy Inc | Midland, TX 79702 | Oil & Gas Operator | Mar 2008 |
| 145 | Costilla Petroleum Corporation | Midland, TX 79702 | Oil & Gas Operator | Mar 2015 |
| 146 | Cotton Valley Resources, LLC | Kilgore, TX 75663 | Oil & Gas Operator | Feb 2025 |
| 147 | Couch Oil & Gas, Inc. | Dallas, TX 75229 | Oil & Gas Operator | Oct 2025 |
| 148 | Cox & Perkins Exploration, Inc. | Houston, TX 77057 | Oil & Gas Operator | Oct 2025 |
| 149 | Crawford Energy Operating Co | Houston, TX 77056 | Oil & Gas Operator | Aug 2008 |
| 150 | Crawford Hughes Operating Co. | The Woodlands, TX 77380 | Oil & Gas Operator | Oct 2025 |
| 151 | Crest Resources & Expl. Corp. | Houston, TX 77079 | Oil & Gas Operator | Dec 1998 |
| 152 | Crimson Exploration Inc. | Houston, TX 77060 | Oil & Gas Operator | Apr 2006 |
| 153 | Crimson Exploration Oper., Inc. | Houston, TX 77002 | Oil & Gas Operator | Dec 2019 |
| 154 | Crown Petroleum Corp. | Oklahoma City, OK 73106 | Oil & Gas Operator | Oct 2025 |
| 155 | Csa Exploration Company, Inc. | Houston, TX 77027 | Oil & Gas Operator | Aug 2003 |
| 156 | CXL Energy LLC | Canada, 00100 | Oil & Gas Operator | Oct 2025 |
| 157 | Cxy Energy, Inc. | Dallas, TX 75251 | Oil & Gas Operator | Nov 2000 |
| 158 | Cypress E & P Corporation | Leander, TX 78646 | Oil & Gas Operator | Sep 2016 |
| 159 | D90 Energy, LLC | Houston, TX 77024 | Oil & Gas Operator | Oct 2025 |
| 160 | Dale Operating Company | Dallas, TX 75201 | Oil & Gas Operator | Oct 2025 |
| 161 | Dallas Petroleum Group, LLC | Dallas, TX 75379 | Oil & Gas Operator | Oct 2025 |
| 162 | Dallas Production, Inc. | Dallas, TX 75206 | Oil & Gas Operator | Mar 2021 |
| 163 | Dantex Oil & Gas, Inc. | Dallas, TX 75225 | Oil & Gas Operator | Aug 2003 |
| 164 | Davidson Production Company, LLC | Bertram, TX 78605 | Oil Operator | Oct 2025 |
| 165 | Davidson, Grover R. | Bertram, TX 78605 | Oil & Gas Operator | Oct 2025 |
| 166 | Davis Bros. Oil Producers, Inc. | Tulsa, OK 74119 | Oil & Gas Operator | Apr 2020 |
| 167 | Davis, A. L. Production Co.,Inc. | Van Vleck, TX 77482 | Oil & Gas Operator | Aug 2003 |
| 168 | Davis, C. O. Production Co. | Bay City, TX 77414 | Oil & Gas Operator | Oct 2025 |
| 169 | Davis, J. R. Oil Company | Sweeny, TX 77480 | Oil & Gas Operator | Oct 2025 |
| 170 | Davis, Larry D. | Boling, TX 77420 | Oil & Gas Operator | Oct 2025 |
| 171 | Daylight Petroleum LLC | Houston, TX 77052 | Oil & Gas Operator | Oct 2025 |
| 172 | DCP Operating Co LP | Houston, TX 77042 | Oil & Gas Operator | May 2025 |
| 173 | Decker Operating Co., L.L.C. | Houston, TX 77008 | Oil & Gas Operator | Oct 2025 |
| 174 | Del Petroleum Corporation | Dallas, TX 75219 | Oil & Gas Operator | Jan 2012 |
| 175 | Delaware Davis Petroleum Corp. | Houston, TX 77056 | Oil & Gas Operator | Jan 2000 |
| 176 | Delco Operating Company LP | Houston, TX 77056 | Oil & Gas Operator | May 2020 |
| 177 | Delray Oil, Inc. | San Antonio, TX 78209 | Oil & Gas Operator | Oct 2025 |
| 178 | Denovo Oil & Gas, Inc. | Houston, TX 77210 | Oil & Gas Operator | May 1995 |
| 179 | Devon Energy Production Company LP | Oklahoma City, OK 73102 | Oil & Gas Operator | Oct 2025 |
| 180 | Dewbre Petroleum Corporation | Corpus Chrsti, TX 78404 | Oil & Gas Operator | Oct 2025 |
| 181 | Diasu Oil & Gas Co., Inc. | Houston, TX 77002 | Oil & Gas Operator | Mar 2016 |
| 182 | Dinero Oil Corporation | Corpus Chrsti, TX 78460 | Oil & Gas Operator | Nov 1999 |
| 183 | Discovery Energy Corp. CC | Corpus Chrsti, TX 78403 | Oil & Gas Operator | Oct 2025 |
| 184 | DKW Energy, Inc. | Sherman Oaks, CA 91403 | Oil & Gas Operator | Oct 2025 |
| 185 | DMS Oil Company | Houston, TX 77042 | Oil & Gas Operator | Aug 2025 |
| 186 | Dominion Exploration & Production Inc | Houston, TX 77060 | Oil & Gas Operator | Apr 2015 |
| 187 | Dominion Oklahoma Texas E&P, Inc | Richmond, VA 23219 | Oil & Gas Operator | Sep 2018 |
| 188 | Dominion Production Company, LLC | Tampa, FL 33606 | Oil & Gas Operator | Oct 2025 |
| 189 | Dorado Oil Company | Corpus Chrsti, TX 78403 | Oil & Gas Operator | Oct 2013 |
| 190 | Double Play Oil & Gas, Inc | Portland, TX 78374 | Oil & Gas Operator | Oct 2025 |
| 191 | Dreyfus, Louis Natural Gas Corp | Oklahoma City, OK 73134 | Oil & Gas Operator | Nov 2001 |
| 192 | Driscoll S.W.D. Inc. | San Antonio, TX 78229 | Oil & Gas Operator | Oct 2025 |
| 193 | Duderstadt, A. R. | Boling, TX 77420 | Oil & Gas Operator | Oct 2025 |
| 194 | Duncan Oil Inc | Denver, CO 80210 | Oil & Gas Operator | Jun 2016 |
| 195 | Dynamic Production, Inc. | Fort Worth, TX 76106 | Oil & Gas Operator | Oct 2025 |
| 196 | Eagle Energy Development Co | La Porte, TX 77571 | Oil & Gas Operator | Dec 2024 |
| 197 | Eagle Oil & Gas Co. | Dallas, TX 75225 | Oil & Gas Operator | Oct 2025 |
| 198 | Eei Operating Inc. | Plano, TX 75093 | Oil & Gas Operator | May 2015 |
| 199 | Eex Corporation | Houston, TX 77060 | Oil & Gas Operator | Feb 2000 |
| 200 | Eex E&P Company, L.P. | Houston, TX 77060 | Oil & Gas Operator | Jul 2003 |