| 101 | Columbia Gulf Transmission Co. | | Oil Operator | Dec 2014 |
| 102 | Columbia Gulf Transmission Company, LLC | | Oil Operator | Jan 2025 |
| 103 | Conoco Inc. | Houston, TX 77252 | Oil & Gas Operator | Mar 2015 |
| 104 | Consolidated Resources Inc | | Oil & Gas Operator | May 2004 |
| 105 | Continental Operating Co. | Houston, TX 77024 | Oil & Gas Operator | Oct 2025 |
| 106 | Coronado Energy E&P Company, LLC | Houston, TX 77252 | Oil & Gas Operator | Dec 2010 |
| 107 | Cotton Petroleum Corporation | Tulsa, OK 74102 | Oil & Gas Operator | Jan 2005 |
| 108 | Cougar Exploration, Inc. | | Oil & Gas Operator | Jun 1988 |
| 109 | Cox Oil & Gas, Inc. | Dallas, TX 75201 | Oil & Gas Operator | Mar 2014 |
| 110 | Crab Run Gas Company | | Oil & Gas Operator | Feb 1982 |
| 111 | Crain & Dore Production Co Inc | | Oil & Gas Operator | Oct 1990 |
| 112 | Credo Petroleum Corporation | Denver, CO 80202 | Oil & Gas Operator | Jan 2013 |
| 113 | Crescent DRLG & DVLPMNT, Inc. | | Oil & Gas Operator | Oct 1992 |
| 114 | Crosstex Lig, LLC | | Oil Operator | Mar 2014 |
| 115 | Crown Central Petroleum Corp | Richmond, TX 77469 | Oil & Gas Operator | Dec 1999 |
| 116 | Crystal Oil And Land Company | | Oil & Gas Operator | May 1992 |
| 117 | Cummins & Walker Oil Co., Inc. | Austin, TX 78746 | Oil & Gas Operator | Jan 2021 |
| 118 | CX Operating, Inc. | | Oil & Gas Operator | Oct 2023 |
| 119 | Cxy Energy, Inc. | Dallas, TX 75251 | Oil & Gas Operator | Nov 2000 |
| 120 | Cypress Oil Company, Inc. | | Oil & Gas Operator | Aug 2003 |
| 121 | Cypress Production, Inc. | Azle, TX 76020 | Oil & Gas Operator | Oct 2025 |
| 122 | D. B. McClinton | | Oil & Gas Operator | Jun 1992 |
| 123 | D. C. Bintliff Et Al | | Oil & Gas Operator | Feb 1987 |
| 124 | D90 Energy, LLC | Houston, TX 77024 | Oil & Gas Operator | Oct 2025 |
| 125 | Damian Oil, Inc. | | Oil & Gas Operator | Dec 2024 |
| 126 | Damson Oil Corporation | Houston, TX 77210 | Oil & Gas Operator | Mar 2005 |
| 127 | Damson-Franks-McCord-Goodrich | | Oil & Gas Operator | Aug 1984 |
| 128 | Daniel Oil Company | | Oil & Gas Operator | Jan 1983 |
| 129 | Dant Operating Company Inc. | | Oil & Gas Operator | Jan 1989 |
| 130 | Dardan Expl Inc-H Edison Ellis | | Oil & Gas Operator | Apr 1990 |
| 131 | Darsey Operating Corporation | | Oil & Gas Operator | Sep 1990 |
| 132 | Davis Petroleum Corp. | Houston, TX 77027 | Oil & Gas Operator | Oct 2025 |
| 133 | Daylight Petroleum LLC | Houston, TX 77052 | Oil & Gas Operator | Oct 2025 |
| 134 | DBL DRLG.&Prod. Services, Inc. | | Oil & Gas Operator | Jul 1997 |
| 135 | Delta Energy Resources, Inc. | | Oil & Gas Operator | Jun 1990 |
| 136 | Delta Petroleum Corp Of Co | | Oil & Gas Operator | Oct 2010 |
| 137 | Delta Petroleum Inc | Houston, TX 77269-1007 | Oil & Gas Operator | May 2009 |
| 138 | Denovo Oil & Gas, Inc. | Houston, TX 77210 | Oil & Gas Operator | May 1995 |
| 139 | Devon Louisiana Corporation | Houston, TX 77002 | Oil & Gas Operator | Oct 2019 |
| 140 | Dew Oil And Gas Co.,Inc. | | Oil & Gas Operator | Dec 1989 |
| 141 | Drew Cornell, Inc. | | Oil & Gas Operator | Jun 1992 |
| 142 | Duer Wagner & Company | Fort Worth, TX 76102 | Oil & Gas Operator | Dec 1998 |
| 143 | Duncan Energy Company | Denver, CO 80202 | Oil & Gas Operator | Mar 2008 |
| 144 | Duncan Oil Inc | Denver, CO 80210 | Oil & Gas Operator | Jun 2016 |
| 145 | Dynamic Exploration, Inc. | | Oil & Gas Operator | Oct 2003 |
| 146 | E & E Production Company, Inc. | | Oil & Gas Operator | Dec 2004 |
| 147 | E Lee Mills | | Oil Operator | Aug 1987 |
| 148 | Eagle Energy Development Co | La Porte, TX 77571 | Oil & Gas Operator | Dec 2024 |
| 149 | Ed I. Estis | | Oil & Gas Operator | Sep 1998 |
| 150 | Edge Petroleum Oper. Co., Inc. | Houston, TX 77042 | Oil & Gas Operator | Nov 2010 |
| 151 | Edwin L. Cox | | Oil & Gas Operator | May 1986 |
| 152 | Edwin L. Cox & Berry R. Cox | | Oil & Gas Operator | Jun 1986 |
| 153 | El Paso E&P Company, L.P. | Houston, TX 77002 | Oil & Gas Operator | Mar 2013 |
| 154 | El-Oil, LTD. | | Oil & Gas Operator | Nov 2024 |
| 155 | Eland Energy Inc | Dallas, TX 75248 | Oil & Gas Operator | Jul 2025 |
| 156 | Eldon Radke | | Oil Operator | May 2001 |
| 157 | Elf Aquitaine Operating, Inc. | | Oil & Gas Operator | Jan 1992 |
| 158 | Elliott Oil & Gas Company | The Woodlands, TX 77380 | Oil & Gas Operator | Sep 2006 |
| 159 | Elysium Energy, L.L.C. | Denver, CO 80202 | Oil & Gas Operator | Jun 2019 |
| 160 | Elysium Jennings, LLC | | Oil & Gas Operator | Dec 2024 |
| 161 | Empire Land Corporation | New Orleans, LA 70130 | Oil & Gas Operator | Nov 2014 |
| 162 | Energen Resources Maq Inc | Birmingham, AL 35203 | Oil & Gas Operator | Sep 2000 |
| 163 | Energy Development Corporation | Houston, TX 77067 | Oil & Gas Operator | Dec 2024 |
| 164 | Energy Investments Inc | | Oil & Gas Operator | Aug 2025 |
| 165 | Energy Research & Dev. Corp. | | Oil & Gas Operator | Feb 1998 |
| 166 | Energy Reserves Group | Houston, TX 770563020 | Oil & Gas Operator | Apr 1996 |
| 167 | Energyquest II, LLC | The Woodlands, TX 77381 | Oil & Gas Operator | Jun 2025 |
| 168 | Energyquest Management, LLC | Houston, TX 77090 | Oil & Gas Operator | Apr 2021 |
| 169 | Enervest Operating LLC | Houston, TX 77002 | Oil & Gas Operator | Oct 2025 |
| 170 | Enlink Lig, LLC | | Oil Operator | Jan 2025 |
| 171 | EP Energy E&P Company, LP | Houston, TX 77210 | Oil & Gas Operator | Jan 2023 |
| 172 | Equinox Oil Company | Plainville, KS 67663 | Oil & Gas Operator | Dec 2019 |
| 173 | Equipment, Inc. | | Oil & Gas Operator | Mar 1983 |
| 174 | Equitable Petroleum Corp. | | Oil & Gas Operator | Jan 1999 |
| 175 | Est. Of H. L. Hunt | | Oil & Gas Operator | Jun 1983 |
| 176 | Etc Oil Corp | | Oil & Gas Operator | Mar 1994 |
| 177 | Eucutta Petroleum Inc. | | Oil & Gas Operator | Sep 2000 |
| 178 | Evangeline Oil Prod. Co., Inc. | | Oil Operator | Apr 2001 |
| 179 | Evangeline Operating Co., Inc. | | Oil Operator | Jun 1989 |
| 180 | Exodus Energy, Inc. | Huntington Beach, CA 92615 | Oil & Gas Operator | Jul 2018 |
| 181 | Expando Production Co. | | Oil & Gas Operator | Oct 1988 |
| 182 | Extex Operating Company | Houston, TX 77057 | Oil & Gas Operator | Oct 2025 |
| 183 | Exxon Corporation | Houston, TX 77210 | Oil & Gas Operator | Jun 2024 |
| 184 | Faul Energy, Inc. | | Oil & Gas Operator | Oct 1988 |
| 185 | Fin-Oil, Inc. | | Oil & Gas Operator | Apr 1985 |
| 186 | Fina Oil And Chemical Company | Dallas, TX 75221 | Oil & Gas Operator | May 2019 |
| 187 | Finaly Resources LLC | Sunset Beach, CA 90742 | Oil & Gas Operator | Oct 2025 |
| 188 | First Energy Corporation | | Oil & Gas Operator | Jun 1993 |
| 189 | First Energy Development Corp. | | Oil & Gas Operator | Sep 2008 |
| 190 | Five-Jab, Inc. | Tomball, TX 77377 | Oil & Gas Operator | Oct 2025 |
| 191 | Flash Gas & Oil Northeast, Inc | | Oil & Gas Operator | May 2007 |
| 192 | Florida Exploration Co | Aurora, CO 80014 | Oil & Gas Operator | Sep 1989 |
| 193 | Florida Gas Transmission Co. | | Oil Operator | Dec 2007 |
| 194 | Flynn Energy Corporation | Tulsa, OK 74137 | Oil & Gas Operator | Mar 1993 |
| 195 | FMP Operating Co., LTD. PTN. | | Oil & Gas Operator | Mar 1990 |
| 196 | Forman Petroleum Corporation | | Oil & Gas Operator | Aug 2001 |
| 197 | Forza Operating, LLC | The Woodlands, TX 77380 | Oil & Gas Operator | Oct 2025 |
| 198 | Four Rivers Exploration, Inc. | | Oil & Gas Operator | Sep 2002 |
| 199 | Franks & Petrofunds, Inc. | | Oil & Gas Operator | Sep 1989 |
| 200 | Franks - Arkla | | Oil & Gas Operator | Jun 1985 |