| 101 | Crimson Exploration Oper., Inc. | Houston, TX 77002 | Oil & Gas Operator | Dec 2019 |
| 102 | Cross Timbers Operating Company | Fort Worth, TX 76102 | Oil & Gas Operator | Dec 2025 |
| 103 | Crusader Energy Corporation | Oklahoma City, OK 73102 | Oil & Gas Operator | Sep 2011 |
| 104 | Crusader Energy Group Inc. | Austin, TX 78746 | Oil & Gas Operator | Mar 2015 |
| 105 | Crusader Energy Group LLC | Oklahoma City, OK 73142 | Oil & Gas Operator | Mar 2015 |
| 106 | Crusader Energy II LLC | Oklahoma City, OK 73102 | Oil & Gas Operator | Mar 2015 |
| 107 | Crystal River Oil & Gas LLC | Snowmass VLG., CO 81615 | Oil & Gas Operator | Jan 2023 |
| 108 | D & E Oil Co | Perryton, TX 79070 | Oil & Gas Operator | Apr 2026 |
| 109 | D C Energy, Inc. | Oklahoma City, OK 73134 | Oil & Gas Operator | Apr 2020 |
| 110 | D.W.P. Production | Perryton, TX 79070 | Oil & Gas Operator | Nov 2020 |
| 111 | Dallas Production, Inc. | Dallas, TX 75206 | Oil & Gas Operator | Mar 2021 |
| 112 | Daniels Energy | Pampa, TX 79066 | Oil & Gas Operator | Apr 2026 |
| 113 | Daniels, Earlene | Follett, TX 79034 | Oil & Gas Operator | Feb 2002 |
| 114 | Daniels, J.C. Energy | Pampa, TX 79066 | Oil & Gas Operator | Apr 2001 |
| 115 | DCP Operating Co LP | Houston, TX 77042 | Oil & Gas Operator | Nov 2025 |
| 116 | Deep Reef Industries | Amarillo, TX 79101 | Oil & Gas Operator | Jan 2004 |
| 117 | Denali Exploration, Inc. | Amarillo, TX 79109 | Oil & Gas Operator | Nov 2018 |
| 118 | Derrick Exploration, Inc. | Amarillo, TX 79105 | Oil & Gas Operator | Jan 2003 |
| 119 | Devon Energy Corp (Nevada) | Oklahoma City, OK 73102 | Oil & Gas Operator | Feb 2017 |
| 120 | Devon Energy Production Company, L.P. | Oklahoma City, OK 73102 | Oil & Gas Operator | Apr 2026 |
| 121 | Di Energy Inc. | Houston, TX 77067 | Oil & Gas Operator | Jan 2004 |
| 122 | Diamond S Energy Company | Fort Worth, TX 76132 | Oil & Gas Operator | Apr 2026 |
| 123 | Diamondback Resources LLC | Midland, TX 79705 | Oil & Gas Operator | May 2018 |
| 124 | Dinero Operating Co | Midland, TX 79702 | Oil & Gas Operator | Apr 2026 |
| 125 | Discovery Operating Inc | Midland, TX 79705 | Oil & Gas Operator | Apr 2026 |
| 126 | Diversified Production LLC | Keithville, LA 71047 | Oil & Gas Operator | Apr 2026 |
| 127 | DMS Oil Company | Houston, TX 77042 | Oil & Gas Operator | Jan 2026 |
| 128 | Dominion Oklahoma Texas E&P, Inc | Richmond, VA 23219 | Oil & Gas Operator | Sep 2018 |
| 129 | Double Eagle Petroleum Corp | Evansville, IN 47725 | Oil & Gas Operator | Apr 2026 |
| 130 | Dreyfus, Louis Natural Gas Corp | Oklahoma City, OK 73134 | Oil & Gas Operator | Nov 2001 |
| 131 | Dugan Production Corp | Farmington, NM 87499 | Oil & Gas Operator | Feb 2026 |
| 132 | Duncan Oil Properties, Inc. | Oklahoma City, OK 73102 | Oil & Gas Operator | Apr 2026 |
| 133 | Dunne Equities Operating, Inc. | Houston, TX 77057 | Oil & Gas Operator | Aug 2022 |
| 134 | Dunne Equities, Inc. | Wichita, KS 67226 | Oil & Gas Operator | Apr 2014 |
| 135 | E R Operating Company | Dallas, TX 75225 | Oil & Gas Operator | Jan 2025 |
| 136 | E. T. S. Enterprises, Inc. | Amarillo, TX 79105 | Oil & Gas Operator | Jul 1996 |
| 137 | E.G. Operating | Dallas, TX 75206 | Oil & Gas Operator | Mar 2008 |
| 138 | E.G.L. Resources, Inc. | Midland, TX 79702 | Oil & Gas Operator | Apr 2025 |
| 139 | E2 Operating LLC | Tulsa, OK 74135 | Oil & Gas Operator | Apr 2026 |
| 140 | Eagle Oil & Gas Co. | Dallas, TX 75225 | Oil & Gas Operator | Apr 2026 |
| 141 | Eagle Rock Mid-Continent Op, LLC | Houston, TX 77252 | Oil & Gas Operator | Sep 2015 |
| 142 | El Paso Production Company | Houston, TX 77002 | Oil & Gas Operator | Mar 2016 |
| 143 | Eland Energy Inc | Dallas, TX 75248 | Oil & Gas Operator | Feb 2026 |
| 144 | Elson Oil Company | Tulsa, OK 74103-4429 | Oil & Gas Operator | Dec 2016 |
| 145 | Empire Operating, Inc. | Pampa, TX 79066 | Oil & Gas Operator | Mar 2017 |
| 146 | Enable Midstream Partners, LP | Oklahoma City, OK 73124 | Oil Operator | Sep 2023 |
| 147 | Encore Operating LP | Plano, TX 75024 | Oil & Gas Operator | Feb 2026 |
| 148 | Energy Transfer Crude Marketing LLC | Dallas, TX 75225 | Oil Operator | Jan 2026 |
| 149 | Energy Transfer Fuel, LP | Houston, TX 77002 | Oil & Gas Operator | Apr 2005 |
| 150 | Enervest Operating LLC | Houston, TX 77002 | Oil & Gas Operator | Apr 2026 |
| 151 | Enron Oil & Gas Company | Houston, TX 77210 | Oil & Gas Operator | Dec 1999 |
| 152 | Enserch Exploration Inc | Dallas, TX 75206 | Oil & Gas Operator | Apr 2015 |
| 153 | EOG Resources Inc | Midland, TX 79702 | Oil & Gas Operator | Apr 2026 |
| 154 | EP Operating Limited Partnership | Dallas, TX 75201 | Oil & Gas Operator | Feb 1995 |
| 155 | Eqv Operating LLC | Oklahoma City, OK 73172 | Oil & Gas Operator | Apr 2026 |
| 156 | Estes And Company LLC. | Perryton, TX 79070 | Oil & Gas Operator | Apr 2026 |
| 157 | Et Gathering & Processing LLC | Dallas, TX 75225 | Oil Operator | Dec 2024 |
| 158 | Etc Field Services LLC | San Antonio, TX 78258 | Oil Operator | Jun 2018 |
| 159 | Etc Texas Pipeline, LTD. | Dallas, TX 75225 | Oil Operator | Sep 2023 |
| 160 | Eurovest Oil & Gas, Inc. | Graham, TX 76450 | Oil & Gas Operator | Mar 2008 |
| 161 | Exco Resources Inc | Dallas, TX 75251 | Oil & Gas Operator | Jan 2026 |
| 162 | Exxon Corporation | Houston, TX 77210 | Oil & Gas Operator | Apr 2026 |
| 163 | Exxon Mobil Corporation | Spring, TX 77389 | Oil & Gas Operator | Apr 2026 |
| 164 | Fagadau Energy Corporation | Dallas, TX 75206 | Oil & Gas Operator | Apr 2006 |
| 165 | Fairway Resources Op III, LLC | Southlake, TX 76092 | Oil & Gas Operator | Apr 2026 |
| 166 | Far West Development, LLC | Oklahoma City, OK 73118 | Oil & Gas Operator | Apr 2026 |
| 167 | Faulconer Energy, LLC | Tyler, TX 75711 | Oil & Gas Operator | Apr 2026 |
| 168 | Faulconer, Vernon E., Inc. | Tyler, TX 75711 | Oil & Gas Operator | Feb 2026 |
| 169 | Federer, H. C. | Amarillo, TX 79101 | Oil & Gas Operator | Dec 1993 |
| 170 | Finaly Resources LLC | Sunset Beach, CA 90742 | Oil & Gas Operator | Apr 2026 |
| 171 | Finley Resources Inc | Fort Worth, TX 76113 | Oil & Gas Operator | Apr 2026 |
| 172 | Flairtex Resources, Inc. | Houston, TX 77040 | Oil & Gas Operator | Oct 1998 |
| 173 | Follett Operating Co. | Darrouzett, TX 79024 | Oil & Gas Operator | Jun 2019 |
| 174 | Forest Oil Corporation | Houston, TX 77002 | Oil & Gas Operator | Mar 2015 |
| 175 | Forestar Petroleum Corporation | Denver, CO 80202 | Oil & Gas Operator | May 2017 |
| 176 | Fort Worth Natural Gas, Inc. | Dallas, TX 75254 | Oil & Gas Operator | Apr 2026 |
| 177 | Fortay Inc. | Sunray, TX 79086 | Oil & Gas Operator | Apr 2026 |
| 178 | Fredonia Resources Inc. | Longview, TX 75606 | Oil & Gas Operator | Aug 2003 |
| 179 | Future Petroleum Corporation | Houston, TX 77002 | Oil & Gas Operator | Sep 1999 |
| 180 | FX Energy Operating, LLC | Canadian, TX 79014 | Oil & Gas Operator | Apr 2026 |
| 181 | G. & S. Inc. | Gruver, TX 79040 | Oil & Gas Operator | Nov 2023 |
| 182 | General Atlantic Resources Inc | Denver, CO 80202 | Oil & Gas Operator | Jan 2022 |
| 183 | Gothic Energy Corporation | Tulsa, OK 74136 | Oil & Gas Operator | Jul 2015 |
| 184 | Grace Petroleum Corp. | Tulsa, OK 74103 | Oil & Gas Operator | Oct 1997 |
| 185 | Granite Operating Company | Houston, TX 77056 | Oil & Gas Operator | Nov 2012 |
| 186 | Graves Operating | Perryton, TX 79070 | Oil & Gas Operator | Jul 2005 |
| 187 | Graves Operating, LLC | Perryton, TX 79070 | Oil & Gas Operator | Apr 2026 |
| 188 | Great Horned Owls Pulsatrix, LLC | Pampa, TX 79066 | Oil & Gas Operator | Apr 2026 |
| 189 | Grizzly Op Of Delaware, LLC | Houston, TX 77057 | Oil & Gas Operator | Mar 2021 |
| 190 | Gruy Petroleum Management Co. | Irving, TX 75014 | Oil & Gas Operator | Nov 2014 |
| 191 | Guest Petroleum Incorporated | Edmond, OK 73013 | Oil & Gas Operator | Feb 2026 |
| 192 | Guest R E Oil Producer | Edmond, OK 73083-0805 | Oil & Gas Operator | Mar 2015 |
| 193 | Gunsmoke Energy Company | Fort Worth, TX 76132 | Oil & Gas Operator | May 2012 |
| 194 | H & L Exploration Company, LLC | Amarillo, TX 79114 | Oil & Gas Operator | Apr 2026 |
| 195 | H & L Operating Co., L.L.P. | Amarillo, TX 79114 | Oil & Gas Operator | Aug 2022 |
| 196 | H & L Operating Co., LLC | Amarillo, TX 79114 | Oil & Gas Operator | Mar 2021 |
| 197 | H & L Operating Company | Amarillo, TX 79114 | Oil & Gas Operator | Feb 2020 |
| 198 | H-S Exploration | Gunnison, CO 81230 | Oil & Gas Operator | Apr 2026 |
| 199 | Hadaway Consult And Engineer,LLC | Canadian, TX 79014 | Oil & Gas Operator | Apr 2026 |
| 200 | Hadaway Engineering Inc | Canadian, TX 79014 | Oil & Gas Operator | Jul 2015 |