| 101 | CT Adams Jr., LLC | Schulenburg, TX 78956 | Oil Operator | Oct 2025 |
| 102 | CTR Petroleum, Inc. | Corpus Chrsti, TX 78414 | Oil & Gas Operator | Mar 2015 |
| 103 | Cypress E & P Corporation | Leander, TX 78646 | Oil & Gas Operator | Sep 2016 |
| 104 | Dale Operating Company | Dallas, TX 75201 | Oil & Gas Operator | Oct 2025 |
| 105 | Dallas Petroleum Group, LLC | Dallas, TX 75379 | Oil & Gas Operator | Oct 2025 |
| 106 | Dallas Production, Inc. | Dallas, TX 75206 | Oil & Gas Operator | Mar 2021 |
| 107 | Dartex Energy Corporation | Austin, TX 78746 | Oil & Gas Operator | Oct 2025 |
| 108 | Davenport Oil Company | Luling, TX 78648 | Oil & Gas Operator | Dec 1996 |
| 109 | DCP Operating Co LP | Houston, TX 77042 | Oil & Gas Operator | May 2025 |
| 110 | Dee-Jay Exploration Company | Nichols Hill, OK 73116 | Oil & Gas Operator | Oct 2025 |
| 111 | Del Petroleum Corporation | Dallas, TX 75219 | Oil & Gas Operator | Jan 2012 |
| 112 | Delaware Ecco Petroleum Inc. | Rockwall, TX 75087 | Oil & Gas Operator | Jul 2001 |
| 113 | Delray Oil, Inc. | San Antonio, TX 78209 | Oil & Gas Operator | Oct 2025 |
| 114 | Denali Oil & Gas Management, LLC | Houston, TX 77060 | Oil & Gas Operator | Dec 2012 |
| 115 | Devine, C. R., Inc. | Houston, TX 77292 | Oil & Gas Operator | Feb 2018 |
| 116 | Dominion Oklahoma Texas E&P, Inc | Richmond, VA 23219 | Oil & Gas Operator | Sep 2018 |
| 117 | Douglas Petroleum Inc. | Spring, TX 77379 | Oil & Gas Operator | Nov 2010 |
| 118 | Dreyfus, Louis Natural Gas Corp | Oklahoma City, OK 73134 | Oil & Gas Operator | Nov 2001 |
| 119 | Durst Oil Company | Corpus Chrsti, TX 78477 | Oil & Gas Operator | Sep 2000 |
| 120 | Dynamic Production, Inc. | Fort Worth, TX 76106 | Oil & Gas Operator | Oct 2025 |
| 121 | Dyson Energy Operating, LLC | Bryan, TX 77802 | Oil & Gas Operator | Jun 2018 |
| 122 | Earthstone Operating, LLC | The Woodlands, TX 77380 | Oil & Gas Operator | Jul 2025 |
| 123 | Eclipse Services, Inc. * | La Grange, TX 78945 | Oil & Gas Operator | Jul 2003 |
| 124 | Edco Energy, Inc. | Austin, TX 78738 | Oil & Gas Operator | May 2003 |
| 125 | El Paso Production Oil & Gas Co. | Houston, TX 77252 | Oil & Gas Operator | Oct 2025 |
| 126 | Eland Energy Inc | Dallas, TX 75248 | Oil & Gas Operator | Jul 2025 |
| 127 | Elfco, Inc. | College Sta, TX 77845 | Oil & Gas Operator | Jun 1996 |
| 128 | Elliott Oil & Gas Company | The Woodlands, TX 77380 | Oil & Gas Operator | Sep 2006 |
| 129 | Elliott Oil & Gas Operating Co. | Magnolia, TX 77354 | Oil & Gas Operator | Oct 2025 |
| 130 | Emerald Operating Company | Plano, TX 75075 | Oil & Gas Operator | Aug 2025 |
| 131 | Encino Exploration, Inc. | George West, TX 78022 | Oil & Gas Operator | Oct 2025 |
| 132 | Energy Oil & Gas Corporation | Austin, TX 78746 | Oil & Gas Operator | Oct 2025 |
| 133 | Energy Transfer Crude Marketing LLC | Dallas, TX 75225 | Oil Operator | May 2025 |
| 134 | Enerquest Oil & Gas LLC | Oklahoma City, OK 73114 | Oil & Gas Operator | Jun 2025 |
| 135 | Enervest Operating LLC | Houston, TX 77002 | Oil & Gas Operator | Oct 2025 |
| 136 | Enex Resources Corporation | Houston, TX 77002 | Oil & Gas Operator | Dec 2009 |
| 137 | Engroup Resources, L.P. | Houston, TX 77002 | Oil & Gas Operator | Oct 2025 |
| 138 | EOG Resources, Inc. | Midland, TX 79702 | Oil & Gas Operator | Oct 2025 |
| 139 | Ernest Operating Company | Rockdale, TX 76567 | Oil & Gas Operator | Oct 2025 |
| 140 | Esenjay Petroleum Corp. | Corpus Chrsti, TX 78471 | Oil & Gas Operator | Jul 1998 |
| 141 | Estate Oil & Gas Corp. | Dallas, TX 75206 | Oil & Gas Operator | Oct 2011 |
| 142 | Et Gathering & Processing LLC | Dallas, TX 75225 | Oil Operator | Dec 2024 |
| 143 | Etc Texas Pipeline, LTD. | Dallas, TX 75225 | Oil Operator | Sep 2023 |
| 144 | Evolution Operating Co., Inc. | Houston, TX 77079 | Oil & Gas Operator | Oct 2025 |
| 145 | Exco Resources Inc | Dallas, TX 75251 | Oil & Gas Operator | Jun 2025 |
| 146 | Express Oil Co. | Hallettsville, TX 77964 | Oil & Gas Operator | Oct 2025 |
| 147 | Exxon Corporation | Houston, TX 77210 | Oil & Gas Operator | Jun 2024 |
| 148 | F.I.G. Energy, LLC | Livingston, TX 77399 | Oil & Gas Operator | Oct 2025 |
| 149 | F.M.C. Operating, Inc. | Austin, TX 78750 | Oil & Gas Operator | Oct 1996 |
| 150 | Falcon Oil & Gas Company, Inc. | Houston, TX 77002 | Oil & Gas Operator | Nov 2022 |
| 151 | Fenn, Bill Inc. | Giddings, TX 78942 | Oil & Gas Operator | Mar 2008 |
| 152 | FGB Energy, Inc. | Dallas, TX 75206 | Oil & Gas Operator | Aug 2017 |
| 153 | Finley Resources Inc | Fort Worth, TX 76113 | Oil & Gas Operator | Oct 2025 |
| 154 | Flare Resources Inc. | Houston, TX 77002 | Gas Operator | Jun 2006 |
| 155 | Flatonia Energy, LLC | Dallas, TX 75201 | Oil & Gas Operator | Oct 2025 |
| 156 | Ford, Don H. & Assoc. | San Antonio, TX 78217 | Oil & Gas Operator | Oct 2025 |
| 157 | Forestar Petroleum Corporation | Denver, CO 80202 | Oil & Gas Operator | May 2017 |
| 158 | Forney & McCombs | Houston, TX 77056 | Oil & Gas Operator | Jan 1998 |
| 159 | Fortune Operating Company | Willis, TX 77378 | Oil & Gas Operator | Oct 2025 |
| 160 | Frazier Exploration Partners,LLC | Houston, TX 77057 | Oil & Gas Operator | Oct 2025 |
| 161 | Fredonia Resources Inc. | Longview, TX 75606 | Oil & Gas Operator | Aug 2003 |
| 162 | Frostwood Energy, LLC | Houston, TX 77219 | Oil & Gas Operator | Oct 2025 |
| 163 | Future Petroleum Company LLC | Houston, TX 77027 | Oil & Gas Operator | Jun 2013 |
| 164 | Future Petroleum Corporation | Houston, TX 77002 | Oil & Gas Operator | Sep 1999 |
| 165 | Gaither Petroleum Corporation | Katy, TX 77493 | Oil & Gas Operator | Oct 2025 |
| 166 | Gei Management Co., Inc. | Houston, TX 77024 | Oil & Gas Operator | Sep 1993 |
| 167 | Gemini Exploration Company | Dallas, TX 75219 | Oil & Gas Operator | Mar 1997 |
| 168 | Genepa Petroleum Company | Spring, TX 77379 | Oil & Gas Operator | Oct 2025 |
| 169 | General Oil Company, Inc. | Wichita, KS 67213 | Oil & Gas Operator | Oct 2025 |
| 170 | Genie Corporation | Abilene, TX 79604 | Oil & Gas Operator | Mar 2008 |
| 171 | Geonatural Resources, Inc. | Dallas, TX 75240 | Oil & Gas Operator | Oct 2025 |
| 172 | Geosouthern Energy Corporation | The Woodlands, TX 77380 | Oil & Gas Operator | Oct 2025 |
| 173 | Geosouthern Operating II, LLC | The Woodlands, TX 77380 | Oil & Gas Operator | Oct 2025 |
| 174 | Gifford Operating Company | Dallas, TX 75206 | Oil & Gas Operator | Jul 2003 |
| 175 | Ginger Petroleum Company, Inc. | La Grange, TX 78945 | Oil & Gas Operator | Oct 2025 |
| 176 | Glade Operating, LLC | San Antonio, TX 78280 | Oil Operator | Oct 2025 |
| 177 | Goldking Prod. Co. | Houston, TX 77002 | Oil & Gas Operator | Apr 1998 |
| 178 | Goldston Oil Corporation | Houston, TX 77257 | Oil & Gas Operator | Oct 2025 |
| 179 | Great West Energy & Expl., Inc. | Addison, TX 75001 | Oil & Gas Operator | Mar 2008 |
| 180 | Great Western Drilling Co | Midland, TX 79701 | Oil & Gas Operator | Oct 2025 |
| 181 | Gsi Oil & Gas, Inc. | Bryan, TX 77806 | Oil & Gas Operator | Oct 2025 |
| 182 | H - A Energy, Inc. | Midland, TX 79704 | Oil & Gas Operator | Oct 2025 |
| 183 | Hampton Resources Corporation | Houston, TX 77010 | Oil & Gas Operator | Mar 1996 |
| 184 | Hankamer, Curtis Corporation,The | Houston, TX 77024 | Oil & Gas Operator | Oct 2025 |
| 185 | Hardin Energy Co., Inc. | Bigfoot, TX 78005 | Oil Operator | Oct 2025 |
| 186 | Hardin, W.V. Estate | San Antonio, TX 78258 | Oil & Gas Operator | Apr 2002 |
| 187 | Harrison Oil & Gas Inc | Houston, TX 77019 | Oil & Gas Operator | Jun 2025 |
| 188 | Harrison, Sam G. Oil, Inc. | Houston, TX 77019 | Oil & Gas Operator | Nov 2019 |
| 189 | Henry Petroleum Corp. | Midland, TX 79703 | Oil & Gas Operator | Mar 2001 |
| 190 | Hep Oil Company LTD | Gainesville, TX 76240 | Oil & Gas Operator | Mar 2012 |
| 191 | Higher Standard Oil Company,Inc. | Frisco, TX 75034 | Oil Operator | Oct 2025 |
| 192 | Hillin, T. A. | Kerrville, TX 78028 | Oil & Gas Operator | Aug 2020 |
| 193 | Hillin-Simon Oil Company | Houston, TX 77079 | Oil & Gas Operator | Mar 2013 |
| 194 | HK Energy Operating, LLC | Houston, TX 77002 | Oil & Gas Operator | May 2023 |
| 195 | Holifield Oil Company | Giddings, TX 78942 | Oil & Gas Operator | Mar 2009 |
| 196 | Holley Oil Company, LLC | Chappell Hill, TX 77426 | Oil & Gas Operator | Oct 2025 |
| 197 | Hollub, Lambert Drilling Company | Seguin, TX 78155 | Oil & Gas Operator | Oct 2025 |
| 198 | Hopkins Engineering, Inc. | Houston, TX 77046 | Oil & Gas Operator | Sep 1996 |
| 199 | Houston Oil & Minerals Corp. | Houston, TX 77002 | Oil & Gas Operator | Aug 1996 |
| 200 | Houston Resources Corp. | Houston, TX 77002 | Oil & Gas Operator | Apr 2003 |