| 101 | D. G. Oil Co. | Dennis, TX 76439 | Oil & Gas Operator | Oct 2025 |
| 102 | D. Shel Oil, Inc. | Gonzales, TX 78629 | Oil Operator | Oct 2025 |
| 103 | Dakota Resources, Inc. (I) | Midland, TX 79707 | Oil & Gas Operator | Oct 2025 |
| 104 | Dantex Oil & Gas, Inc. | Dallas, TX 75225 | Oil & Gas Operator | Aug 2003 |
| 105 | Davenport Oil Company | Luling, TX 78648 | Oil & Gas Operator | Dec 1996 |
| 106 | DCP Operating Co LP | Houston, TX 77042 | Oil & Gas Operator | May 2025 |
| 107 | Dee-Jay Exploration Company | Nichols Hill, OK 73116 | Oil & Gas Operator | Oct 2025 |
| 108 | Delcar, Inc. | San Antonio, TX 78209 | Oil & Gas Operator | Oct 1995 |
| 109 | Delco Operating Company LP | Houston, TX 77056 | Oil & Gas Operator | May 2020 |
| 110 | Delong, Horace | Pleasanton, TX 78064 | Oil & Gas Operator | Oct 2025 |
| 111 | Delray Oil, Inc. | San Antonio, TX 78209 | Oil & Gas Operator | Oct 2025 |
| 112 | Delta Exploration Company Inc | Denver, CO 80202 | Oil & Gas Operator | Oct 2025 |
| 113 | Denali Oil & Gas Management, LLC | Houston, TX 77060 | Oil & Gas Operator | Dec 2012 |
| 114 | Devon Energy Production Company LP | Oklahoma City, OK 73102 | Oil & Gas Operator | Oct 2025 |
| 115 | Devon Gas Services, L.P. | Oklahoma City, OK 73102 | Oil & Gas Operator | Nov 2015 |
| 116 | Di Energy Inc. | Houston, TX 77067 | Oil & Gas Operator | Jan 2004 |
| 117 | Diamond M DRLG & Expl Co. | San Antonio, TX 78217 | Oil & Gas Operator | Oct 2025 |
| 118 | Dinero Oil Corporation | Corpus Chrsti, TX 78460 | Oil & Gas Operator | Nov 1999 |
| 119 | Dirnett, Inc. | Tuleta, TX 78162 | Oil & Gas Operator | Oct 2025 |
| 120 | Dolch Production, Inc. | San Antonio, TX 78248 | Oil & Gas Operator | Jul 1996 |
| 121 | Dominion Minerals Corporation | Houston, TX 77014 | Oil & Gas Operator | Nov 2009 |
| 122 | Dominion Production Company, LLC | Tampa, FL 33606 | Oil & Gas Operator | Oct 2025 |
| 123 | Dorado Oil Company | Corpus Chrsti, TX 78403 | Oil & Gas Operator | Oct 2013 |
| 124 | Double Play Oil & Gas, Inc | Portland, TX 78374 | Oil & Gas Operator | Oct 2025 |
| 125 | Dreyfus, Louis Natural Gas Corp | Oklahoma City, OK 73134 | Oil & Gas Operator | Nov 2001 |
| 126 | Driscoll S.W.D. Inc. | San Antonio, TX 78229 | Oil & Gas Operator | Oct 2025 |
| 127 | E.G.L. Resources, Inc. | Midland, TX 79702 | Oil & Gas Operator | Apr 2025 |
| 128 | Eagle Ford Hunter Resources,Inc. | Houston, TX 77024 | Oil & Gas Operator | Apr 2013 |
| 129 | Earthstone Operating, LLC | The Woodlands, TX 77380 | Oil & Gas Operator | Jul 2025 |
| 130 | East Texas Production MGT. Inc | Athens, TX 75751 | Oil & Gas Operator | Oct 2025 |
| 131 | Edco Energy, Inc. | Austin, TX 78738 | Oil & Gas Operator | May 2003 |
| 132 | Emerald Operating Company | Plano, TX 75075 | Oil & Gas Operator | Aug 2025 |
| 133 | Endeavor Energy Resources, LP | Midland, TX 79701 | Oil & Gas Operator | Mar 2025 |
| 134 | Energy Equity Company | Columbus, MT 59019 | Oil & Gas Operator | Aug 2025 |
| 135 | Energy Resources Oil & Gas Corp. | Amarillo, TX 79102 | Oil & Gas Operator | Jun 1994 |
| 136 | Energy Transfer Crude Marketing LLC | Dallas, TX 75225 | Oil Operator | May 2025 |
| 137 | Enerquest Oil & Gas LLC | Oklahoma City, OK 73114 | Oil & Gas Operator | Jun 2025 |
| 138 | Enerquest Operating, LLC | Oklahoma City, OK 73114 | Oil & Gas Operator | Oct 2025 |
| 139 | Enervest Operating LLC | Houston, TX 77002 | Oil & Gas Operator | Oct 2025 |
| 140 | Enre Corp. | San Antonio, TX 78209 | Oil & Gas Operator | Mar 2005 |
| 141 | Enron Oil & Gas Company | Houston, TX 77210 | Oil & Gas Operator | Dec 1999 |
| 142 | EOG Resources, Inc. | Midland, TX 79702 | Oil & Gas Operator | Oct 2025 |
| 143 | EP Energy E&P Company, LP | Houston, TX 77210 | Oil & Gas Operator | Jan 2023 |
| 144 | Esenjay Petroleum Corp. | Corpus Chrsti, TX 78471 | Oil & Gas Operator | Jul 1998 |
| 145 | Etc Field Services LLC | San Antonio, TX 78258 | Oil Operator | Jun 2018 |
| 146 | Etc Texas Pipeline, LTD. | Dallas, TX 75225 | Oil Operator | Sep 2023 |
| 147 | Evantech Energy Corp. | Fort Worth, TX 76120 | Oil & Gas Operator | Apr 1995 |
| 148 | Evergreen Operating Co., LTD. | McAllen, TX 78502 | Oil & Gas Operator | Oct 2025 |
| 149 | Express Oil Co. | Hallettsville, TX 77964 | Oil & Gas Operator | Oct 2025 |
| 150 | Fair Oil Company | Tyler, TX 75710 | Oil & Gas Operator | Dec 2000 |
| 151 | Fair Oil, LC | Tyler, TX 75710 | Oil & Gas Operator | Oct 2001 |
| 152 | Fair Oil, LTD. | Tyler, TX 75710 | Oil & Gas Operator | Oct 2025 |
| 153 | FGB Energy, Inc. | Dallas, TX 75206 | Oil & Gas Operator | Aug 2017 |
| 154 | Field Petroleum Corp. | San Antonio, TX 78216 | Oil & Gas Operator | Oct 2025 |
| 155 | Fina Oil And Chemical Company | Dallas, TX 75221 | Oil & Gas Operator | May 2019 |
| 156 | Finaly Resources LLC | Sunset Beach, CA 90742 | Oil & Gas Operator | Oct 2025 |
| 157 | Finger Oil & Gas, Inc. | Castroville, TX 78009 | Oil & Gas Operator | May 2021 |
| 158 | First Rock, Inc. | Corpus Chrsti, TX 78401 | Oil & Gas Operator | Oct 2025 |
| 159 | Flatonia Energy, LLC | Dallas, TX 75201 | Oil & Gas Operator | Oct 2025 |
| 160 | Force 4 Energy Resources, Inc. | Austin, TX 78733 | Oil & Gas Operator | Aug 2005 |
| 161 | Ford, Don H. & Assoc. | San Antonio, TX 78217 | Oil & Gas Operator | Oct 2025 |
| 162 | Forest Oil Corporation | Houston, TX 77002 | Oil & Gas Operator | Mar 2015 |
| 163 | Fortune Resources LLC | Longview, TX 75604 | Oil & Gas Operator | Oct 2025 |
| 164 | Frazier Exploration Partners,LLC | Houston, TX 77057 | Oil & Gas Operator | Oct 2025 |
| 165 | Fredco | Louise, TX 77455 | Oil & Gas Operator | Oct 2025 |
| 166 | G & K Operating, LLC | Poth, TX 78147 | Oil & Gas Operator | Oct 2025 |
| 167 | G & M Gas & Oil | Midland, TX 79701 | Oil & Gas Operator | Jun 1998 |
| 168 | Galilee Oil Investments LLC | San Antonio, TX 78205 | Oil & Gas Operator | Oct 2025 |
| 169 | Gardner Energy Corporation | Houston, TX 77024 | Oil & Gas Operator | Mar 1999 |
| 170 | Gassco Petroleum Corporation | Seguin, TX 78155 | Oil & Gas Operator | Oct 2025 |
| 171 | GBF Operating LLC | Morrison, CO 80465 | Oil & Gas Operator | Oct 2025 |
| 172 | Gda Investments Inc | Oklahoma City, OK 73123-0403 | Oil & Gas Operator | Jun 2025 |
| 173 | Geo-Graphic Production, Inc. | Gonzales, TX 78629 | Oil & Gas Operator | Oct 2025 |
| 174 | Geodyne Operating Company | Tulsa, OK 74103 | Oil & Gas Operator | Jun 2015 |
| 175 | Geosouthern Energy Corporation | The Woodlands, TX 77380 | Oil & Gas Operator | Oct 2025 |
| 176 | Gibraltar Petroleum Corporation | Mabank, TX 75147 | Oil & Gas Operator | Nov 2008 |
| 177 | Gibraltar Resources, Inc. | Dallas, TX 75374 | Oil & Gas Operator | Jul 1993 |
| 178 | Ginger Petroleum Company, Inc. | La Grange, TX 78945 | Oil & Gas Operator | Oct 2025 |
| 179 | Glade Operating, LLC | San Antonio, TX 78280 | Oil Operator | Oct 2025 |
| 180 | Glassell, Alfred C., Jr. | Houston, TX 77002 | Oil & Gas Operator | Apr 2007 |
| 181 | Glenco Oil & Gas Company | Seguin, TX 78155 | Oil & Gas Operator | Dec 1994 |
| 182 | GN&J LLC | Pharr, TX 78577 | Oil & Gas Operator | Oct 2025 |
| 183 | Golden Child, Inc. | San Antonio, TX 78213 | Oil & Gas Operator | Oct 2025 |
| 184 | Goldking Prod. Co. | Houston, TX 77002 | Oil & Gas Operator | Apr 1998 |
| 185 | Goldmark Energy Corporation | Spring, TX 77393 | Oil & Gas Operator | Jul 2010 |
| 186 | Goldston Oil Corporation | Houston, TX 77257 | Oil & Gas Operator | Oct 2025 |
| 187 | Gruy Petroleum Management Co. | Irving, TX 75014 | Oil & Gas Operator | Nov 2014 |
| 188 | Gsi Oil & Gas, Inc. | Bryan, TX 77806 | Oil & Gas Operator | Oct 2025 |
| 189 | Gulftex Energy III, LP | San Antonio, TX 78257 | Oil & Gas Operator | Jul 2018 |
| 190 | Gulftex Energy, LLC | San Antonio, TX 78257 | Oil & Gas Operator | Oct 2025 |
| 191 | H And H | Gonzales, TX 78629 | Oil Operator | Feb 1999 |
| 192 | H&K Energy | Stockdale, TX 78160 | Oil & Gas Operator | Jul 2005 |
| 193 | Ha.P.C. Oil, Inc. | Gonzales, TX 78629 | Oil & Gas Operator | Aug 2006 |
| 194 | Hamilton Brothers Oil Co. | Houston, TX 77057 | Oil & Gas Operator | Mar 2015 |
| 195 | Hampton Resources Corporation | Houston, TX 77010 | Oil & Gas Operator | Mar 1996 |
| 196 | Haring Energy Company | Tuleta, TX 78162 | Oil & Gas Operator | Mar 2003 |
| 197 | Harrier Holdings, LTD. | Burnet, TX 78611 | Oil Operator | Oct 2025 |
| 198 | Hart Petroleum Services, Inc | Corpus Chrsti, TX 78410 | Oil & Gas Operator | Jul 2025 |
| 199 | Harvey, Robert E., Jr. | Nixon, TX 78140 | Oil & Gas Operator | Oct 2003 |
| 200 | Hat Creek Energy LLC | Denver, CO 80209 | Oil & Gas Operator | Jun 2019 |