| 101 | Tesoro Petroleum Corporation | | Oil & Gas Operator | May 1982 |
| 102 | Tesoro-Bintliff | | Oil & Gas Operator | Nov 1982 |
| 103 | Tex-Con-Brehm-Basin Expl. | | Oil & Gas Operator | May 1990 |
| 104 | Tex/Con Oil & Gas Company | Houston, TX 77074 | Oil & Gas Operator | Feb 2001 |
| 105 | Texaco E & P Inc. | Houston, TX 77099 | Oil & Gas Operator | Feb 2026 |
| 106 | Texaco Inc | Kingfisher, OK 73750 | Oil & Gas Operator | Dec 2017 |
| 107 | Texaco Inc & A.C. Glassell Jr | | Oil & Gas Operator | Aug 1980 |
| 108 | Texaco Oils Inc | Tulsa, OK 74102-2420 | Oil & Gas Operator | Jan 2003 |
| 109 | Texaco Producing Inc. | Rock Springs, WY 82901 | Oil & Gas Operator | Dec 2000 |
| 110 | Texada Resources, Inc. | | Oil & Gas Operator | Dec 1992 |
| 111 | Texakoma Operating, L.P. | Plano, TX 75024 | Oil & Gas Operator | Mar 2025 |
| 112 | Texana Operating Company | Houston, TX 77090 | Oil & Gas Operator | Feb 2026 |
| 113 | Texas City Refining, Inc. | | Oil & Gas Operator | Nov 1988 |
| 114 | Texas Crude & Dale Gas Expl | | Oil & Gas Operator | Dec 1984 |
| 115 | Texas Crude Exploration Inc | Fort Worth, TX 76116 | Oil & Gas Operator | Aug 1992 |
| 116 | Texas Crude Oil Co. | | Oil & Gas Operator | Dec 1984 |
| 117 | Texas Crude Oil Co. Et Al | | Oil & Gas Operator | May 1992 |
| 118 | Texas Crude Oil, Inc. | | Oil & Gas Operator | Dec 1984 |
| 119 | Texas Crude Operator, Inc. | Houston, TX 77098 | Oil & Gas Operator | Aug 2017 |
| 120 | Texas Crude, Inc. | Houston, TX 77256 | Oil & Gas Operator | Oct 1995 |
| 121 | Texas Crude-Rebstock & Reeves | | Oil & Gas Operator | Feb 1980 |
| 122 | Texas Crude-Wainoco-Hilliard | | Oil & Gas Operator | Jul 1978 |
| 123 | Texas Eastern Skyline Oil Co. | | Oil & Gas Operator | Jan 1987 |
| 124 | Texas Eastern Transm. Corp. | | Oil & Gas Operator | Dec 2002 |
| 125 | Texas Energy & Environmental Inc | Houston, TX 77269 | Oil & Gas Operator | Oct 1998 |
| 126 | Texas Energy Oil & Gas Corp. | | Oil & Gas Operator | Sep 1982 |
| 127 | Texas Gas Exploration Corp. | | Oil & Gas Operator | Nov 1986 |
| 128 | Texas Gas Transmission Corp. | | Oil Operator | Aug 2003 |
| 129 | Texas Gas Transmission, LLC | Owensboro, KY 42301 | Oil & Gas Operator | Dec 2024 |
| 130 | Texas General Petroleum Corp | | Oil & Gas Operator | Aug 1984 |
| 131 | Texas Ind. Exploration, Inc. | | Oil & Gas Operator | Oct 2001 |
| 132 | Texas Meridian Operating Co. Inc | Houston, TX 77079 | Oil & Gas Operator | Oct 1993 |
| 133 | Texas Meridian Res. Expl., Inc. | Houston, TX 77079 | Oil & Gas Operator | Jun 1998 |
| 134 | Texas Oil & Gas Corporation | Dallas, TX 75201 | Oil & Gas Operator | Feb 2001 |
| 135 | Texas Pacific Oil Co. | | Oil & Gas Operator | Dec 1980 |
| 136 | Texas Petroleum Investment Company | Houston, TX 77057 | Oil & Gas Operator | Feb 2026 |
| 137 | Texas T Oil Co. | | Oil & Gas Operator | Apr 1990 |
| 138 | Texasgulf Inc. | Newgulf, TX 77462 | Oil & Gas Operator | Jul 1994 |
| 139 | Texeast Operating Co., Inc. | Farmers BRNCH, TX 75234 | Oil Operator | Feb 2026 |
| 140 | Texegy Operating Company LLC | Corpus Chrsti, TX 78401 | Oil & Gas Operator | Dec 2024 |
| 141 | Texex Petroleum Corporation | | Oil & Gas Operator | Dec 2024 |
| 142 | Texla Operating Co | Jonesville, TX 75659 | Oil & Gas Operator | Feb 2026 |
| 143 | Texlan Oil Company, Inc. | Tyler, TX 75701 | Oil & Gas Operator | Nov 1994 |
| 144 | Texoil Company | | Oil & Gas Operator | Dec 2000 |
| 145 | Texoma Production Co | | Oil & Gas Operator | Jun 1986 |
| 146 | Texona Petroleum Corporation | Houston, TX 77084 | Oil & Gas Operator | Aug 2003 |
| 147 | Texstar Petroleum, Inc. | Houston, TX 77002 | Oil & Gas Operator | Nov 2000 |
| 148 | TGNR TVL LLC | Houston, TX 77002 | Oil & Gas Operator | Dec 2024 |
| 149 | TGX Corporation | Houston, TX 77002 | Oil & Gas Operator | Sep 2004 |
| 150 | Tharp Operating Company | Houston, TX 77070 | Oil & Gas Operator | Nov 2014 |
| 151 | The B&B Oil Co Of Sabine Inc | | Oil Operator | Jun 1982 |
| 152 | The B&C Corp-Imp Amer MGT Co | | Oil & Gas Operator | Aug 1981 |
| 153 | The Ballard & Cordell Corp | | Oil & Gas Operator | Feb 1982 |
| 154 | The Bering Company | | Oil Operator | Jul 1979 |
| 155 | The Cornell Corporation | Fort Worth, TX 76109 | Oil & Gas Operator | Sep 1993 |
| 156 | The Exploration Co. Of La, Inc | | Oil & Gas Operator | Nov 1987 |
| 157 | The George R Brown Partnership | | Oil & Gas Operator | Jun 1992 |
| 158 | The Goro Corporation | | Oil & Gas Operator | Jul 1978 |
| 159 | The Harvest Group, LLC | | Oil & Gas Operator | May 2011 |
| 160 | The Hunter Company, Inc. | | Oil & Gas Operator | Sep 1985 |
| 161 | The Maurice L. Brown Company | | Oil & Gas Operator | Aug 1987 |
| 162 | The Meridian Res. & Exp. LLC | | Oil & Gas Operator | Sep 2010 |
| 163 | The Meridian Resource & Exp Co | | Oil & Gas Operator | Dec 2000 |
| 164 | The Pioneer | | Gas Operator | Feb 2008 |
| 165 | The Romanoff Corporation | | Oil & Gas Operator | Nov 1989 |
| 166 | The Southern Louisiana Expl. Company LLC | | Oil & Gas Operator | Nov 2024 |
| 167 | The Stone Oil Corporation | | Oil & Gas Operator | May 1985 |
| 168 | The Stone Petro Corp-Toce Oil | | Oil & Gas Operator | Oct 1984 |
| 169 | The Superior Oc WM Scully Etal | | Oil & Gas Operator | Apr 1986 |
| 170 | The Superior Oil Co & Pel-Tex | | Oil & Gas Operator | Apr 1986 |
| 171 | The Superior Oil Co - Tesoro | | Oil & Gas Operator | Apr 1986 |
| 172 | The Termo Company | Long Beach, CA 90801 | Oil & Gas Operator | Dec 2025 |
| 173 | The WM G Helis Company, L.L.C. | | Oil & Gas Operator | Nov 2003 |
| 174 | Tholl Oil Company | | Oil Operator | Dec 2003 |
| 175 | Thomas Aitken, Inc. | | Gas Operator | Dec 2024 |
| 176 | Thomas Bell | | Oil Operator | Dec 1985 |
| 177 | Thomas C. Hoffpauir | | Oil & Gas Operator | Mar 1991 |
| 178 | Thomas C. Hoffpauir, Inc. | | Oil & Gas Operator | Jan 1981 |
| 179 | Thomas E. Slack | | Oil Operator | Mar 2003 |
| 180 | Thomas G. Easterling | | Oil Operator | Jun 1989 |
| 181 | Thomas Turman | | Oil & Gas Operator | Dec 1991 |
| 182 | Thor Production Co. | | Oil Operator | May 1997 |
| 183 | Thor-Max Operating, Inc. | Plano, TX 75025 | Oil & Gas Operator | Feb 2026 |
| 184 | Thornton & Brooks, Inc. | | Oil & Gas Operator | Oct 1990 |
| 185 | Thornton Page Natural Gas | | Oil & Gas Operator | Dec 2024 |
| 186 | Thrall Texas Oil, LLC | | Oil & Gas Operator | Jan 2025 |
| 187 | Three "N" One Production | | Oil & Gas Operator | Dec 2011 |
| 188 | Three D Petroleum LLC | | Oil Operator | Dec 2024 |
| 189 | Three S & T Oil Co., Inc. | | Oil & Gas Operator | May 1985 |
| 190 | Three Sisters Investments, LTD | | Oil & Gas Operator | Oct 1989 |
| 191 | Three Sisters Petroleum, Inc. | Oil City, LA 71061 | Oil & Gas Operator | Jan 2025 |
| 192 | Threshold Development Company | Fort Worth, TX 76109 | Oil & Gas Operator | Aug 2016 |
| 193 | THT Operating Company | | Oil & Gas Operator | Jul 1990 |
| 194 | Thunderstone Exploration, Inc. | | Oil & Gas Operator | Oct 2006 |
| 195 | Tide West Oil Company | Tulsa, OK 74136 | Oil & Gas Operator | Mar 2021 |
| 196 | Tideland Industries, Inc. | | Oil & Gas Operator | Dec 1989 |
| 197 | Tideway Oil Programs, Inc. | | Oil & Gas Operator | Oct 1980 |
| 198 | Tierra Petroleum Corp. | | Oil & Gas Operator | Jun 1987 |
| 199 | Tigco Oil & Gas Co., Inc. | | Oil & Gas Operator | Nov 2014 |
| 200 | Tiger Oil Company | Dallas, TX 75221 | Oil & Gas Operator | May 2007 |