| 101 | Comstock Oil & Gas, LP | Frisco, TX 75034 | Oil & Gas Operator | Aug 2019 |
| 102 | Conoco Inc | Houston, TX 77252 | Oil & Gas Operator | Mar 2015 |
| 103 | ConocoPhillips Company | Midland, TX 79701 | Oil & Gas Operator | Apr 2026 |
| 104 | Continental Operating Co. | Houston, TX 77024 | Oil & Gas Operator | Apr 2026 |
| 105 | Corda Corporation | Wichita Falls, TX 76308 | Oil & Gas Operator | Apr 2026 |
| 106 | Cordele Development Corporation | San Antonio, TX 78205 | Oil & Gas Operator | Apr 2026 |
| 107 | Coronado Energy E&P Company, LLC | Houston, TX 77252 | Oil & Gas Operator | Dec 2010 |
| 108 | Corpus Christi Leaseholds, Inc. | Corpus Chrsti, TX 78403 | Oil & Gas Operator | Sep 1996 |
| 109 | Costilla Energy, Inc. | Midland, TX 79702 | Oil & Gas Operator | Mar 2008 |
| 110 | Costilla Petroleum Corporation | Midland, TX 79702 | Oil & Gas Operator | Mar 2015 |
| 111 | Cox Exploration, Inc. | Dallas, TX 75201 | Oil & Gas Operator | Nov 1999 |
| 112 | Crystal Oil Company | Shreveport, LA 71120 | Oil & Gas Operator | Jul 1995 |
| 113 | CTR Petroleum, Inc. | Corpus Chrsti, TX 78414 | Oil & Gas Operator | Mar 2015 |
| 114 | Cummins & Walker Oil Co., Inc. | Austin, TX 78746 | Oil & Gas Operator | Jan 2021 |
| 115 | Cyber Enviro-Tech Inc | San Tan Valley, AZ 85144 | Oil & Gas Operator | Apr 2026 |
| 116 | D&H-S-S Production Co.,Inc | Corpus Chrsti, TX 78409 | Oil & Gas Operator | Aug 2003 |
| 117 | D.Y. Exploration, Inc. | Boise, ID 83705 | Oil & Gas Operator | Apr 2026 |
| 118 | Da Crowe & Associates, Inc | Chappell Hill, TX 77426 | Oil & Gas Operator | Sep 2010 |
| 119 | Dahco Operating, LLC | Corpus Chrsti, TX 78403 | Oil & Gas Operator | Apr 2026 |
| 120 | Dalen Resources Oil & Gas Co | Dallas, TX 75206 | Oil & Gas Operator | Jun 2010 |
| 121 | Denovo Oil & Gas, Inc. | Houston, TX 77210 | Oil & Gas Operator | May 1995 |
| 122 | Dewbre Petroleum Corporation | Corpus Christ, TX 78404 | Oil & Gas Operator | Apr 2026 |
| 123 | Dinero Oil Corporation | Corpus Chrsti, TX 78460 | Oil & Gas Operator | Nov 1999 |
| 124 | Dirnett, Inc. | Tuleta, TX 78162 | Oil & Gas Operator | Apr 2026 |
| 125 | Discovery Energy Corp. CC | Corpus Chrsti, TX 78403 | Oil & Gas Operator | Apr 2026 |
| 126 | Discovery Petroleum, L.L.C. | Alice, TX 78333 | Oil & Gas Operator | Apr 2026 |
| 127 | Dolphin Petroleum, LP | Alice, TX 78333 | Oil & Gas Operator | Apr 2026 |
| 128 | Dominion Exploration & Production Inc | Houston, TX 77060 | Oil & Gas Operator | Apr 2015 |
| 129 | Dominion Oklahoma Texas E&P, Inc | Richmond, VA 23219 | Oil & Gas Operator | Sep 2018 |
| 130 | Dorado Oil Company | Corpus Chrsti, TX 78403 | Oil & Gas Operator | Oct 2013 |
| 131 | Double Play Oil & Gas, Inc | Portland, TX 78374 | Oil & Gas Operator | Apr 2026 |
| 132 | Dreyfus, Louis Natural Gas Corp | Oklahoma City, OK 73134 | Oil & Gas Operator | Nov 2001 |
| 133 | Drillmar Operating Company | Houston, TX 77019 | Oil & Gas Operator | Jun 2013 |
| 134 | Driscoll S.W.D. Inc. | San Antonio, TX 78229 | Oil & Gas Operator | Apr 2026 |
| 135 | Dugger, Glenn | Alice, TX 78332 | Oil & Gas Operator | Nov 2013 |
| 136 | Dyersdale Energy, L.P. | Kilgore, TX 75663 | Oil & Gas Operator | Apr 2026 |
| 137 | Dynamic Production, Inc. | Fort Worth, TX 76102 | Oil & Gas Operator | Apr 2026 |
| 138 | Eagle Oil & Gas Co. | Dallas, TX 75225 | Oil & Gas Operator | Apr 2026 |
| 139 | Edge Petroleum Oper. Co., Inc. | Houston, TX 77042 | Oil & Gas Operator | Nov 2010 |
| 140 | El Dorado Resources Inc. | Waco, TX 76710 | Oil & Gas Operator | Oct 2009 |
| 141 | El Paso E&P Company, L.P. | Houston, TX 77002 | Oil & Gas Operator | Mar 2013 |
| 142 | El Paso Production Company | Houston, TX 77002 | Oil & Gas Operator | Mar 2016 |
| 143 | El Paso Production Oil & Gas Co. | Houston, TX 77252 | Oil & Gas Operator | Apr 2026 |
| 144 | El Reno Energy, LLC | Granbury, TX 76048 | Oil & Gas Operator | Apr 2026 |
| 145 | El Tres Exploration | Houston, TX 77098 | Oil & Gas Operator | Mar 2008 |
| 146 | Elk Meadows Resources LLC | Houston, TX 77037 | Oil & Gas Operator | Jan 2021 |
| 147 | Ellsworth, H. P. O&G Properties | Corpus Christ, TX 78413 | Oil & Gas Operator | Apr 2026 |
| 148 | Enercorp Resources, Inc. | Houston, TX 77027 | Oil & Gas Operator | Dec 1993 |
| 149 | Energy 2000, Inc. | Reno, NV 89501 | Oil & Gas Operator | Apr 2026 |
| 150 | Energy Development Corporation | Houston, TX 77067 | Oil & Gas Operator | Dec 2025 |
| 151 | Energyquest II, LLC | The Woodlands, TX 77381 | Oil & Gas Operator | Feb 2026 |
| 152 | Enron Oil & Gas Company | Houston, TX 77210 | Oil & Gas Operator | Dec 1999 |
| 153 | Enserch Exploration Inc | Dallas, TX 75206 | Oil & Gas Operator | Apr 2015 |
| 154 | EOG Resources Inc | Midland, TX 79702 | Oil & Gas Operator | Apr 2026 |
| 155 | EP Energy E&P Company, LP | Houston, TX 77210 | Oil & Gas Operator | Jan 2023 |
| 156 | Epstein, Edwin A Jr Oper Co Inc | Las Vegas, NV 89128 | Gas Operator | Dec 2001 |
| 157 | Escudo Oil & Gas, LLC | Houston, TX 77006 | Oil & Gas Operator | Apr 2026 |
| 158 | Esenjay Petroleum Corp. | Corpus Chrsti, TX 78471 | Oil & Gas Operator | Jul 1998 |
| 159 | Etc Texas Pipeline, LTD. | Dallas, TX 75225 | Oil Operator | Sep 2023 |
| 160 | Etoco Incorporated | Houston, TX 77002 | Oil & Gas Operator | May 2005 |
| 161 | Evans, Julian | Houston, TX 77024 | Oil & Gas Operator | Nov 1995 |
| 162 | Exaro Energy II, LLC | Houston, TX 77057 | Oil & Gas Operator | Apr 2026 |
| 163 | Exploration Company, The | San Antonio, TX 78258 | Oil & Gas Operator | Jun 2010 |
| 164 | Exxon Corporation | Houston, TX 77210 | Oil & Gas Operator | Apr 2026 |
| 165 | Exxon Mobil Corporation | Spring, TX 77389 | Oil & Gas Operator | Apr 2026 |
| 166 | Falcon Production Co. | Floresville, TX 78114 | Oil & Gas Operator | Apr 2026 |
| 167 | Fanion Production Co. | San Antonio, TX 78212 | Oil & Gas Operator | Oct 1997 |
| 168 | Fargo Oil & Gas, LLC | Corpus Christ, TX 78415 | Oil & Gas Operator | Apr 2026 |
| 169 | Faulconer Energy, LLC | Tyler, TX 75711 | Oil & Gas Operator | Apr 2026 |
| 170 | Faulconer, Vernon E., Inc. | Tyler, TX 75711 | Oil & Gas Operator | Feb 2026 |
| 171 | Fina Oil And Chemical Company | Dallas, TX 75221 | Oil & Gas Operator | May 2019 |
| 172 | Five-Jab, Inc. | Tomball, TX 77377 | Oil & Gas Operator | Apr 2026 |
| 173 | Fletcher Operating, LLC | Fairhope, AL 36532 | Oil & Gas Operator | Apr 2026 |
| 174 | Flournoy Production Co. | Alice, TX 78333 | Oil & Gas Operator | Dec 2002 |
| 175 | Fordyce Oil & Gas | Sullivan City, TX 78595 | Oil & Gas Operator | Jul 2022 |
| 176 | Forest Oil Corporation | Houston, TX 77002 | Oil & Gas Operator | Mar 2015 |
| 177 | Fox, Hewitt B., Inc. | Corpus Christ, TX 78411 | Oil & Gas Operator | Apr 2026 |
| 178 | Fredco | Louise, TX 77455 | Oil & Gas Operator | Apr 2026 |
| 179 | Freeman Expl. & Prod. Co., Inc. | Houston, TX 77279 | Oil & Gas Operator | Aug 2020 |
| 180 | Frisco Oil Corporation | Tyler, TX 75701 | Oil & Gas Operator | Mar 2000 |
| 181 | Genesis Producing Company | Houston, TX 77024 | Oil & Gas Operator | Oct 2007 |
| 182 | Geodominion Petroleum | Corpus Chrsti, TX 78403 | Oil & Gas Operator | May 2012 |
| 183 | Geodyne Operating Company | Tulsa, OK 74103 | Oil & Gas Operator | Jun 2015 |
| 184 | Glenn, Wayne E. & Assoc., Inc. | Dickinson, TX 77539 | Oil & Gas Operator | Jun 2005 |
| 185 | GMT Inc. | Houston, TX 77042 | Oil & Gas Operator | Jan 2003 |
| 186 | Goldking Prod. Co. | Houston, TX 77002 | Oil & Gas Operator | Apr 1998 |
| 187 | Graham Royalty LTD | Covington, LA 70434 | Oil & Gas Operator | Jul 2007 |
| 188 | Graward Operating, Inc. | Tyler, TX 75701 | Oil & Gas Operator | Apr 2026 |
| 189 | Great Bay Operations, LLC | Portsmouth, NH 03801 | Oil & Gas Operator | Nov 2016 |
| 190 | Great Western Onshore Inc | Houston, TX 77002 | Oil & Gas Operator | Mar 2008 |
| 191 | Greehey & Company, LTD. | San Antonio, TX 78216 | Oil & Gas Operator | May 2020 |
| 192 | Green Exploration Company | Austin, TX 78711 | Oil & Gas Operator | Apr 2026 |
| 193 | Greenbrier Oper. Co. | Dallas, TX 75229 | Oil & Gas Operator | Feb 2001 |
| 194 | GWM Operating Company, LLC | Sugar Land, TX 77496 | Oil & Gas Operator | Apr 2026 |
| 195 | H & P Exploration Co. | Alice, TX 78333 | Oil & Gas Operator | May 2019 |
| 196 | Halcon Resources Operating, Inc. | Tulsa, OK 74135 | Oil & Gas Operator | Dec 2013 |
| 197 | Hallwood Petroleum, Inc. | Midland, TX 79701 | Oil & Gas Operator | Oct 2025 |
| 198 | Hamman Oil & Refining Company | Houston, TX 77098 | Oil & Gas Operator | Apr 2026 |
| 199 | Hanson Minerals Co. | Houston, TX 77042 | Oil & Gas Operator | Oct 1993 |
| 200 | Hanson Production Company | Cuero, TX 77954 | Oil & Gas Operator | Jul 2009 |