| 101 | Comstock Oil & Gas, LP | Frisco, TX 75034 | Oil & Gas Operator | Aug 2019 |
| 102 | ConocoPhillips Company | Midland, TX 79701 | Oil & Gas Operator | May 2025 |
| 103 | Continual Oil & Gas, Inc. | Abilene, TX 79602 | Oil & Gas Operator | May 2025 |
| 104 | Cory, Kenneth W. LTD. | Bellaire, TX 77401 | Oil & Gas Operator | May 2025 |
| 105 | Costilla Energy Inc | Midland, TX 79702 | Oil & Gas Operator | Mar 2008 |
| 106 | Costilla Petroleum Corporation | Midland, TX 79702 | Oil & Gas Operator | Mar 2015 |
| 107 | Cotton Valley Resources, LLC | Kilgore, TX 75663 | Oil & Gas Operator | Feb 2025 |
| 108 | Couch Oil & Gas, Inc. | Dallas, TX 75229 | Oil & Gas Operator | May 2025 |
| 109 | Crawford Energy Operating Co | Houston, TX 77056 | Oil & Gas Operator | Aug 2008 |
| 110 | Crawford Energy, Incorporated | Houston, TX 77056 | Oil & Gas Operator | Mar 2008 |
| 111 | Crawford Hughes Operating Co. | The Woodlands, TX 77380 | Oil & Gas Operator | May 2025 |
| 112 | Crimson Energy Company, LC | Fort Worth, TX 76102 | Oil & Gas Operator | Mar 2004 |
| 113 | Crimson Exploration Oper., Inc. | Houston, TX 77002 | Oil & Gas Operator | Dec 2019 |
| 114 | Cross Timbers Energy, LLC | Fort Worth, TX 76102 | Oil & Gas Operator | May 2025 |
| 115 | Culoco, Inc. | Dallas, TX 75374 | Oil & Gas Operator | Nov 2024 |
| 116 | Cummins & Walker Oil Co., Inc. | Austin, TX 78746 | Oil & Gas Operator | Jan 2021 |
| 117 | Cymri Corporation, The | Houston, TX 77057 | Oil & Gas Operator | Mar 2008 |
| 118 | Cymri, L.L.C. | Houston, TX 77042 | Oil & Gas Operator | May 2025 |
| 119 | Dale Operating Company | Dallas, TX 75201 | Oil & Gas Operator | May 2025 |
| 120 | DCP Operating Co LP | Houston, TX 77042 | Oil & Gas Operator | Feb 2025 |
| 121 | Decker Operating Co., L.L.C. | Houston, TX 77008 | Oil & Gas Operator | May 2025 |
| 122 | Delcar, Inc. | San Antonio, TX 78209 | Oil & Gas Operator | Oct 1995 |
| 123 | Delray Oil, Inc. | San Antonio, TX 78209 | Oil & Gas Operator | May 2025 |
| 124 | Delta Exploration Company Inc | Denver, CO 80202 | Oil & Gas Operator | May 2025 |
| 125 | Devon Energy Production Company LP | Oklahoma City, OK 73102 | Oil & Gas Operator | May 2025 |
| 126 | Devon Gas Services, L.P. | Oklahoma City, OK 73102 | Oil & Gas Operator | Nov 2015 |
| 127 | Devon Louisiana Corporation | Houston, TX 77002 | Oil & Gas Operator | Oct 2019 |
| 128 | Dewbre Petroleum Corporation | Corpus Chrsti, TX 78404 | Oil & Gas Operator | May 2025 |
| 129 | Dillon, H. L., Jr. | Houston, TX 77027 | Oil & Gas Operator | Mar 1996 |
| 130 | Dominion Production Company, LLC | Tampa, FL 33606 | Oil & Gas Operator | May 2025 |
| 131 | Dorado Oil Company | Corpus Chrsti, TX 78403 | Oil & Gas Operator | Oct 2013 |
| 132 | Double Play Oil & Gas, Inc | Portland, TX 78374 | Oil & Gas Operator | May 2025 |
| 133 | Douglas Petroleum Inc. | Spring, TX 77379 | Oil & Gas Operator | Nov 2010 |
| 134 | Dreyfus, Louis Natural Gas Corp | Oklahoma City, OK 73134 | Oil & Gas Operator | Nov 2001 |
| 135 | Dune Operating Company | Dallas, TX 75201 | Oil & Gas Operator | Jun 2016 |
| 136 | Eagle River Energy Corporation | Broken Arrow, OK 74011 | Oil & Gas Operator | Feb 2025 |
| 137 | Earthstone Operating, LLC | The Woodlands, TX 77380 | Oil & Gas Operator | Mar 2025 |
| 138 | Eastland Exploration, Inc. | Austin, TX 78763 | Oil & Gas Operator | Apr 1997 |
| 139 | Edge Petroleum Oper. Co., Inc. | Houston, TX 77042 | Oil & Gas Operator | Nov 2010 |
| 140 | Edinger Engineering, Inc. | Oklahoma City, OK 73102 | Oil & Gas Operator | Mar 2025 |
| 141 | Edinger Inc. | Oklahoma City, OK 73102 | Oil & Gas Operator | Jun 2007 |
| 142 | Eex Corporation | Houston, TX 77060 | Oil & Gas Operator | Feb 2000 |
| 143 | Eex Operating, L.P. | Houston, TX 77060 | Oil & Gas Operator | Jul 2003 |
| 144 | El Paso Production Oil & Gas Co. | Houston, TX 77252 | Oil & Gas Operator | May 2025 |
| 145 | Ellstrom Energy Company | Kingwood, TX 77339 | Oil & Gas Operator | Nov 2000 |
| 146 | Ellsworth, H. P. O&G Properties | Corpus Chrsti, TX 78413 | Oil & Gas Operator | May 2025 |
| 147 | Encana Oil & Gas (USA) Inc. | Denver, CO 80202 | Oil & Gas Operator | Oct 2020 |
| 148 | Enduring Resources, LLC | Greenwood VLG, CO 80111 | Oil & Gas Operator | Mar 2025 |
| 149 | Enercorp Resources, Inc. | Houston, TX 77027 | Oil & Gas Operator | Dec 1993 |
| 150 | Energy Equity Company | Columbus, MT 59019 | Oil & Gas Operator | Mar 2025 |
| 151 | Energy Hunter Resources, Inc. | Houston, TX 77024 | Oil & Gas Operator | Feb 2019 |
| 152 | Energy Resource Management, Inc. | Caldwell, TX 77836 | Oil & Gas Operator | Mar 2008 |
| 153 | Enerquest Oil & Gas LLC | Oklahoma City, OK 73114 | Oil & Gas Operator | Feb 2025 |
| 154 | Enerquest Operating, LLC | Oklahoma City, OK 73114 | Oil & Gas Operator | May 2025 |
| 155 | Enervest Operating LLC | Houston, TX 77002 | Oil & Gas Operator | May 2025 |
| 156 | Enex Resources Corporation | Houston, TX 77002 | Oil & Gas Operator | Dec 2009 |
| 157 | Engelke, R. H. | San Antonio, TX 78230 | Oil & Gas Operator | May 2025 |
| 158 | Enpower Resources Inc. | Sugar Land, TX 77479 | Oil & Gas Operator | May 2025 |
| 159 | Enserch Exploration Inc | Dallas, TX 75206 | Oil & Gas Operator | Apr 2015 |
| 160 | Ensign Operating LLC | Houston, TX 77086 | Oil & Gas Operator | Feb 2023 |
| 161 | EOG Resources, Inc. | Midland, TX 79702 | Oil & Gas Operator | May 2025 |
| 162 | EP Operating Limited Partnership | Dallas, TX 75201 | Oil & Gas Operator | Feb 1995 |
| 163 | Esenjay Exploration, Inc | Houston, TX 77042 | Oil & Gas Operator | Feb 2025 |
| 164 | Esenjay Petroleum Corp. | Corpus Chrsti, TX 78471 | Oil & Gas Operator | Jul 1998 |
| 165 | Estate Of James L. Nelson | Pettus, TX 78146 | Oil & Gas Operator | May 2025 |
| 166 | Etc Field Services LLC | San Antonio, TX 78258 | Oil Operator | Jun 2018 |
| 167 | Etc Texas Pipeline, LTD. | Dallas, TX 75225 | Oil Operator | Sep 2023 |
| 168 | Exotic Oil & Gas LLC | Indiana, PA 15701-3634 | Oil & Gas Operator | Dec 2024 |
| 169 | Express Oil Co. | Hallettsville, TX 77964 | Oil & Gas Operator | May 2025 |
| 170 | Extex Operating Company | Houston, TX 77057 | Oil & Gas Operator | May 2025 |
| 171 | Exxon Corporation | Houston, TX 77210 | Oil & Gas Operator | Jun 2024 |
| 172 | Exxonmobil Oil Corp | Houston, TX 77210 | Oil & Gas Operator | Feb 2025 |
| 173 | Falls City Energy Corporation | Poth, TX 78147 | Oil & Gas Operator | May 2000 |
| 174 | Famcor Oil, Inc. | Scottsdale, AZ 85260 | Oil & Gas Operator | Sep 2020 |
| 175 | Fina Oil And Chemical Company | Dallas, TX 75221 | Oil & Gas Operator | May 2019 |
| 176 | Finger Oil & Gas, Inc. | Castroville, TX 78009 | Oil & Gas Operator | May 2021 |
| 177 | Finley Resources Inc | Fort Worth, TX 76113 | Oil & Gas Operator | May 2025 |
| 178 | First Rock, Inc. | Corpus Chrsti, TX 78401 | Oil & Gas Operator | May 2025 |
| 179 | First Solid Energy Group, LP | Missouri City, TX 77489 | Oil & Gas Operator | May 2025 |
| 180 | Fletcher Operating, LLC | Fairhope, AL 36532 | Oil & Gas Operator | May 2025 |
| 181 | Forest Oil Corporation | Houston, TX 77002 | Oil & Gas Operator | Mar 2015 |
| 182 | Forney & McCombs | Houston, TX 77056 | Oil & Gas Operator | Jan 1998 |
| 183 | Forney Oil Corporation | Houston, TX 77056 | Oil & Gas Operator | Jan 1998 |
| 184 | Forza Operating, LLC | The Woodlands, TX 77380 | Oil & Gas Operator | May 2025 |
| 185 | Foundation Energy Management, LLC | Addison, TX 75001 | Oil & Gas Operator | May 2025 |
| 186 | Francisco Creek Operating, Inc. | Castroville, TX 78009 | Oil Operator | May 2025 |
| 187 | Freddy'S Well Service, Inc. | Victoria, TX 77902 | Oil & Gas Operator | May 2025 |
| 188 | Freeport-McMoran Oil & Gas LLC | Houston, TX 77002 | Oil & Gas Operator | Mar 2025 |
| 189 | Frisco Oil Corporation | Tyler, TX 75701 | Oil & Gas Operator | Mar 2000 |
| 190 | G & K Operating, LLC | Poth, TX 78147 | Oil & Gas Operator | May 2025 |
| 191 | Galloway Energy Co. | Tomball, TX 77377 | Oil & Gas Operator | May 2025 |
| 192 | Genesis Well Service | Colleyville, TX 76034 | Oil Operator | May 2025 |
| 193 | Geo-Graphic Production, Inc. | Gonzales, TX 78629 | Oil & Gas Operator | May 2025 |
| 194 | Geosouthern Energy Corporation | The Woodlands, TX 77380 | Oil & Gas Operator | May 2025 |
| 195 | Gifford Operating Company | Dallas, TX 75206 | Oil & Gas Operator | Jul 2003 |
| 196 | Ginger Petroleum Company, Inc. | La Grange, TX 78945 | Oil & Gas Operator | May 2025 |
| 197 | Glade Operating, LLC | San Antonio, TX 78280 | Oil Operator | May 2025 |
| 198 | Goldking Operating Company, Inc. | Houston, TX 77002 | Oil & Gas Operator | Jun 2007 |
| 199 | Goldking Prod. Co. | Houston, TX 77002 | Oil & Gas Operator | Apr 1998 |
| 200 | Grand Operating, Inc. | Addison, TX 75001 | Oil & Gas Operator | Dec 2020 |