| 101 | Devon Energy Corp (Nevada) | Oklahoma City, OK 73102 | Oil & Gas Operator | Feb 2017 |
| 102 | Discorbis Oil Company | San Antonio, TX 78217 | Oil & Gas Operator | Jul 2019 |
| 103 | Discovery Petroleum, L.L.C. | Alice, TX 78333 | Oil & Gas Operator | Oct 2025 |
| 104 | Double Play Oil & Gas, Inc | Portland, TX 78374 | Oil & Gas Operator | Oct 2025 |
| 105 | Downman Jones Oil Operators, Inc | Brookshire, TX 77423 | Oil & Gas Operator | Jan 2007 |
| 106 | Driscoll S.W.D. Inc. | San Antonio, TX 78229 | Oil & Gas Operator | Oct 2025 |
| 107 | Eagle Ford Oil Co., Inc. | Houston, TX 77057 | Oil & Gas Operator | Oct 2025 |
| 108 | El Paso E&P Company, L.P. | Houston, TX 77002 | Oil & Gas Operator | Mar 2013 |
| 109 | Eland Energy Inc | Dallas, TX 75248 | Oil & Gas Operator | Jul 2025 |
| 110 | Ellsworth, H. P. O&G Properties | Corpus Chrsti, TX 78413 | Oil & Gas Operator | Oct 2025 |
| 111 | Enco Exploration Company | Corpus Chrsti, TX 78401 | Oil & Gas Operator | Apr 2020 |
| 112 | Energy Equity Company | Columbus, MT 59019 | Oil & Gas Operator | Aug 2025 |
| 113 | Energy Frontiers Partners, LP | Grapevine, TX 76051 | Oil Operator | May 2008 |
| 114 | Enex Resources Corporation | Houston, TX 77002 | Oil & Gas Operator | Dec 2009 |
| 115 | Enre Corp. | San Antonio, TX 78209 | Oil & Gas Operator | Mar 2005 |
| 116 | Enre LP | Kingwood, TX 77339 | Oil & Gas Operator | Feb 2004 |
| 117 | EOG Resources, Inc. | Midland, TX 79702 | Oil & Gas Operator | Oct 2025 |
| 118 | EP Energy E&P Company, LLC | Houston, TX 77210 | Oil & Gas Operator | Oct 2025 |
| 119 | EP Energy E&P Company, LP | Houston, TX 77210 | Oil & Gas Operator | Jan 2023 |
| 120 | Escondido Resources GP, LLC | Midland, TX 79708 | Oil & Gas Operator | Dec 2007 |
| 121 | Escondido Resources II, LLC | Houston, TX 77002 | Oil & Gas Operator | Apr 2017 |
| 122 | Escondido Resources Oper Co, LLC | Houston, TX 77002 | Oil & Gas Operator | Oct 2025 |
| 123 | Essman Energy, LLC | Tulsa, OK 74136 | Oil & Gas Operator | Sep 2019 |
| 124 | Estacado Energy, LLC | Iowa Park, TX 76367 | Oil & Gas Operator | Oct 2025 |
| 125 | Etc Field Services LLC | San Antonio, TX 78258 | Oil Operator | Jun 2018 |
| 126 | Exco Operating Company, LP | Dallas, TX 75251 | Oil & Gas Operator | Oct 2025 |
| 127 | Expand Operating LLC | Morgantown, WV 26508 | Oil & Gas Operator | Jun 2025 |
| 128 | Express Oil And Gas | La Grange, TX 78945 | Oil & Gas Operator | Oct 2025 |
| 129 | Express Oil Co. | Hallettsville, TX 77964 | Oil & Gas Operator | Oct 2025 |
| 130 | Exxon Corporation | Houston, TX 77210 | Oil & Gas Operator | Jun 2024 |
| 131 | Exxon Mobil Corporation | Spring, TX 77389 | Oil & Gas Operator | Oct 2025 |
| 132 | F & M Oil Company Inc | Pettus, TX 78146 | Oil & Gas Operator | Oct 2025 |
| 133 | Fenn, Bill Inc. | Giddings, TX 78942 | Oil & Gas Operator | Mar 2008 |
| 134 | First Rock, Inc. | Corpus Chrsti, TX 78401 | Oil & Gas Operator | Oct 2025 |
| 135 | Fletcher Operating, LLC | Fairhope, AL 36532 | Oil & Gas Operator | Oct 2025 |
| 136 | Flournoy Production Co. | Alice, TX 78333 | Oil & Gas Operator | Dec 2002 |
| 137 | Floyd Operating Company | Houston, TX 77002 | Oil & Gas Operator | Jul 2004 |
| 138 | Fortune Operating Company | Willis, TX 77378 | Oil & Gas Operator | Oct 2025 |
| 139 | Fortune Operating, Inc. | Bowling Green, KY 42104 | Oil & Gas Operator | Oct 2025 |
| 140 | Foundation Energy Management, LLC | Addison, TX 75001 | Oil & Gas Operator | Oct 2025 |
| 141 | Fredonia Resources Inc. | Longview, TX 75606 | Oil & Gas Operator | Aug 2003 |
| 142 | Genesis Well Service | Colleyville, TX 76034 | Oil Operator | Oct 2025 |
| 143 | Geodyne Operating Company | Tulsa, OK 74103 | Oil & Gas Operator | Jun 2015 |
| 144 | GGG Oil Co. | Cotulla, TX 78014 | Oil & Gas Operator | Feb 2006 |
| 145 | GGG Oil Company, LTD. | Cotulla, TX 78014 | Oil & Gas Operator | Oct 2025 |
| 146 | Gierhart Exploration, Inc. | Corpus Chrsti, TX 78403 | Oil & Gas Operator | Apr 1994 |
| 147 | Ginco Operating Co. | San Antonio, TX 78217 | Oil & Gas Operator | Oct 2025 |
| 148 | Glenco Oil & Gas Company | Seguin, TX 78155 | Oil & Gas Operator | Dec 1994 |
| 149 | GLG Energy LP | Austin, TX 78701 | Oil & Gas Operator | Jun 1994 |
| 150 | Goodrich Petroleum Company | Houston, TX 77002 | Oil & Gas Operator | Feb 2022 |
| 151 | Grace Petroleum Corp. | Tulsa, OK 74103 | Oil & Gas Operator | Oct 1997 |
| 152 | Great West Energy & Expl., Inc. | Addison, TX 75001 | Oil & Gas Operator | Mar 2008 |
| 153 | Greka Am Inc | Santa Maria, CA 93454 | Oil & Gas Operator | May 2013 |
| 154 | Gulf Production Corporation | Oklahoma City, OK 73114 | Oil & Gas Operator | Apr 2015 |
| 155 | Gulftex Energy IV, LP | San Antonio, TX 78257 | Oil & Gas Operator | Jul 2019 |
| 156 | Gulftex Energy, LLC | San Antonio, TX 78257 | Oil & Gas Operator | Oct 2025 |
| 157 | H & B Petroleum Corp. | Hutchinson, KS 67504 | Oil & Gas Operator | Jun 2025 |
| 158 | Hamman Oil & Refining Company | Houston, TX 77098 | Oil & Gas Operator | Oct 2025 |
| 159 | Hawn Brothers | Corpus Chrsti, TX 78401 | Oil & Gas Operator | Apr 2003 |
| 160 | Hawn Brothers Company | Corpus Chrsti, TX 78401 | Oil & Gas Operator | Jan 2003 |
| 161 | Hawthorn Energy Partners, LLC | Nichols Hill, OK 73116 | Oil & Gas Operator | Oct 2025 |
| 162 | Headline Resources, Inc. | Richardson, TX 75080 | Oil & Gas Operator | Aug 1997 |
| 163 | Hess Corporation | Houston, TX 77010 | Oil & Gas Operator | Aug 2017 |
| 164 | Hilcorp Energy Company | Houston, TX 77208 | Oil & Gas Operator | Oct 2025 |
| 165 | Hill Production Company | Kilgore, TX 75663 | Oil & Gas Operator | Feb 2009 |
| 166 | Hill Production Company No. 2 | Kilgore, TX 75663 | Oil & Gas Operator | Oct 2025 |
| 167 | Holifield Oil Company | Giddings, TX 78942 | Oil & Gas Operator | Mar 2009 |
| 168 | Horizon Natural Resources, Inc. | Tulsa, OK 74136 | Oil & Gas Operator | Jan 2019 |
| 169 | HPC Operating, Inc. | Dallas, TX 75379 | Oil & Gas Operator | Mar 2008 |
| 170 | Hughes, Dan A. Company | Beeville, TX 78104 | Oil & Gas Operator | May 2006 |
| 171 | Hunt Oil Company | Dallas, TX 75201 | Oil & Gas Operator | Oct 2025 |
| 172 | Hunter Petroleum Inc. | Alice, TX 78333 | Oil & Gas Operator | May 2014 |
| 173 | Icarus Operating Corporation | Spring, TX 77393 | Oil & Gas Operator | Oct 2025 |
| 174 | Ineos USA Oil & Gas LLC | Denver, CO 80202 | Oil & Gas Operator | Oct 2025 |
| 175 | Initial Energy Services, LLC | San Antonio, TX 78217 | Oil & Gas Operator | Oct 2025 |
| 176 | Inland Ocean, Inc. | San Antonio, TX 78205 | Oil & Gas Operator | Oct 2025 |
| 177 | Inpex Eagle Ford, LLC | San Antonio, TX 78216 | Oil & Gas Operator | Dec 2022 |
| 178 | J-W Operating Company | Christoval, TX 76935 | Oil & Gas Operator | Oct 2025 |
| 179 | Jab Operating, Inc. | San Antonio, TX 78205 | Oil & Gas Operator | Dec 2008 |
| 180 | Javelin Energy Partners Management, LLC | Irving, TX 75038 | Oil & Gas Operator | Oct 2025 |
| 181 | Jay-Dee Operating Company | Corpus Chrsti, TX 78413 | Oil & Gas Operator | Aug 2000 |
| 182 | JB Oil & Gas Well Service | Dilley, TX 78017 | Oil & Gas Operator | Oct 2025 |
| 183 | Jenex Petroleum Corporation | The Woodlands, TX 77380 | Oil & Gas Operator | Oct 2025 |
| 184 | Kana Resources, Inc. | Dallas, TX 75243 | Oil & Gas Operator | Aug 2003 |
| 185 | Karis Resources, LLC | Tyler, TX 75707 | Oil & Gas Operator | Feb 2019 |
| 186 | Kasan Corp. | Pharr, TX 78577 | Oil & Gas Operator | Sep 1995 |
| 187 | Kebo Oil & Gas, Inc. | Portland, TX 78374 | Oil & Gas Operator | Oct 2025 |
| 188 | Keft Oil Company | Pleasanton, TX 78064 | Oil & Gas Operator | Feb 2003 |
| 189 | Kerns O & G, Inc. | San Antonio, TX 78232 | Oil & Gas Operator | Dec 2004 |
| 190 | Kerr-McGee Corporation | Dallas, TX 75380 | Oil & Gas Operator | May 2025 |
| 191 | Kerr-McGee Oil & Gas Onshore LLC | The Woodlands, TX 77380 | Oil & Gas Operator | Feb 2017 |
| 192 | Kimmeridge Texas Gas, LLC | Houston, TX 77024 | Oil & Gas Operator | Oct 2025 |
| 193 | King Operating Corporation | Fort Worth, TX 76147 | Oil & Gas Operator | Oct 2025 |
| 194 | Kinlaw Oil Corporation | Dallas, TX 75380 | Oil & Gas Operator | Oct 2025 |
| 195 | Kiva Resources Inc. | Houston, TX 77265 | Oil & Gas Operator | Mar 2008 |
| 196 | L & J Exploration, LLC | Carrizo SPGS, TX 78834 | Oil & Gas Operator | Oct 2025 |
| 197 | Lakewood Operating, LTD. | Midland, TX 79702 | Oil & Gas Operator | Oct 2025 |
| 198 | Leede Oil & Gas Inc. | Greenwood VLG, CO 80111 | Oil & Gas Operator | Aug 2003 |
| 199 | Lewis Petro Properties, Inc. | San Antonio, TX 78216 | Oil & Gas Operator | Oct 2025 |
| 200 | Lightning Oil Company | San Antonio, TX 78209 | Oil & Gas Operator | Oct 2025 |