| 201 | Tillman A. Rousse | | Oil Operator | Jan 1990 |
| 202 | Tillman A. Rousse, Inc. | | Oil Operator | Apr 2001 |
| 203 | Tillman J. McIntyre | | Oil Operator | Dec 1987 |
| 204 | Tim Brookover | | Oil & Gas Operator | Dec 2005 |
| 205 | Time Energy, L.L.C. | | Oil & Gas Operator | Nov 2020 |
| 206 | Tipco | Shreveport, LA 71104-3047 | Oil & Gas Operator | May 1988 |
| 207 | Tipco Operating Co. | Marshall, TX 75671 | Oil & Gas Operator | Jun 2025 |
| 208 | Tipperary Oil & Gas Corp | Denver, CO 80202 | Oil & Gas Operator | May 2014 |
| 209 | Titan Oil Corp. | | Oil & Gas Operator | Jan 2025 |
| 210 | Tma Production, LLC | | Oil Operator | Dec 2024 |
| 211 | TMR Exploration, Inc. | Bossier City, LA 71171 | Oil & Gas Operator | Jun 2025 |
| 212 | TNC Energy, LLC | Lubbock, TX 79401 | Oil & Gas Operator | Nov 2016 |
| 213 | Toc, Inc. (TN) | | Oil Operator | Apr 1995 |
| 214 | Toce Energy, L.L.C. | | Oil & Gas Operator | Dec 2017 |
| 215 | Toce Oil Company | | Oil & Gas Operator | Dec 2014 |
| 216 | Todd Bertolet | | Gas Operator | Apr 1999 |
| 217 | Todd Oil Corp. Of La. Inc. | | Oil & Gas Operator | Jul 2000 |
| 218 | Todd Oil Production Co | | Oil Operator | Aug 2001 |
| 219 | Tola Production Company | Dallas, TX 75367 | Oil & Gas Operator | Jun 2025 |
| 220 | Tolar Corporation | | Oil & Gas Operator | Sep 1999 |
| 221 | Tolar Energy, L.L.C. | | Oil & Gas Operator | Dec 2001 |
| 222 | Tolbert & Associates | | Oil Operator | Dec 2024 |
| 223 | Tolbert Et Al | | Oil Operator | Jun 2000 |
| 224 | Tolbert Well Service | | Oil Operator | Jan 2025 |
| 225 | Toledo Bend Well Service | | Oil Operator | Aug 2000 |
| 226 | Tom Brown Inc | Denver, CO 80202 | Oil & Gas Operator | Dec 2004 |
| 227 | Tom Littlepage Oil Properties | | Oil & Gas Operator | Dec 1984 |
| 228 | Tom Moore Trustee | | Oil Operator | Apr 1986 |
| 229 | Tom West | | Oil & Gas Operator | Nov 1989 |
| 230 | Tomlinson Oil Co. Inc. | Great Bend, KS 67530 | Oil & Gas Operator | Jan 2025 |
| 231 | Tommy A. Paul | | Oil Operator | Oct 2020 |
| 232 | Tommy Joe Jenny | | Gas Operator | Nov 2024 |
| 233 | Topaz Oil Company | Diboll, TX 75941 | Oil & Gas Operator | Apr 1994 |
| 234 | Torch Energy Services, Inc. | Houston, TX 77010 | Oil & Gas Operator | Sep 2011 |
| 235 | Torch Oil & Gas Company | Houston, TX 77010 | Oil & Gas Operator | Aug 1997 |
| 236 | Torch Operating Company | Houston, TX 77010 | Oil & Gas Operator | Mar 2015 |
| 237 | Torch Opr Co-Stone Petr Corp | | Oil & Gas Operator | Jul 1997 |
| 238 | Torrid Energy Company | | Oil & Gas Operator | Jun 1988 |
| 239 | Tortuga Operating Company | Houston, TX 77055 | Oil & Gas Operator | Jun 2025 |
| 240 | Total E&P USA, Inc. | Houston, TX 77210 | Oil & Gas Operator | May 2025 |
| 241 | Total Minatome Corporation | Houston, TX 77210 | Oil & Gas Operator | Dec 1998 |
| 242 | Totalfinaelf E&P USA Inc | Houston, TX 77024 | Oil & Gas Operator | Jul 2007 |
| 243 | Touchstone Properties, Inc. | | Oil Operator | Mar 1988 |
| 244 | Trace Operators, Inc. | | Oil & Gas Operator | Nov 2024 |
| 245 | Tracer Energy, Inc. | Graham, TX 76450 | Oil & Gas Operator | Nov 1998 |
| 246 | Trade & Development Corp | | Oil & Gas Operator | Nov 1996 |
| 247 | Tradestar Energy, Inc. | Hot Springs, AR 71913 | Oil Operator | Feb 2021 |
| 248 | Tradition Resources Oper, LLC | Houston, TX 77002 | Oil & Gas Operator | Jul 2017 |
| 249 | Trafalgar House Oil & Gas Inc. | Houston, TX 77002-7346 | Oil & Gas Operator | Jan 1992 |
| 250 | Traillour Oil Co. | | Oil & Gas Operator | Mar 1990 |
| 251 | Trans Ocean Oil, Inc. | Houston, TX 77252 | Oil & Gas Operator | Sep 1980 |
| 252 | Trans-Gulf Petroleum Corp | | Oil & Gas Operator | Sep 1999 |
| 253 | Trans-Pacific Oil & Gas Inc. | | Oil & Gas Operator | Mar 1982 |
| 254 | Trans-Sabine Pipeline Corp | | Oil Operator | Mar 2009 |
| 255 | Trans-Western Expl. Inc. | Dallas, TX 75240 | Oil & Gas Operator | Mar 1993 |
| 256 | Transamerican Energy/Toce Oil | | Oil & Gas Operator | Dec 1994 |
| 257 | Transamerican-Swepi-Toce Oil | | Oil & Gas Operator | Apr 1990 |
| 258 | Transco Exploration Company | | Oil & Gas Operator | Jul 1989 |
| 259 | Transcontinental Gas P/L Corp. | | Oil & Gas Operator | Dec 2009 |
| 260 | Transcontinental Gas Pipeline Co LLC | | Oil Operator | Jan 2025 |
| 261 | Transcontinental Oil Corp. | | Oil & Gas Operator | Sep 1985 |
| 262 | Transfuel Resources Co | Houston, TX 77215 | Oil & Gas Operator | Aug 2013 |
| 263 | Transtexas Gas Corporation | Houston, TX 77265 | Oil & Gas Operator | Aug 2005 |
| 264 | Transworld Expl. & Prod., Inc. | | Oil & Gas Operator | Mar 2004 |
| 265 | Traver Oil & Gas Corporation | | Oil & Gas Operator | Sep 2000 |
| 266 | Traver Oil Company | | Oil & Gas Operator | Sep 2000 |
| 267 | Traver-Patterson Petroleum Inc | | Oil & Gas Operator | May 1990 |
| 268 | Travis E. Duren | | Oil Operator | Jul 1995 |
| 269 | Trebole Operating Company | | Oil Operator | Jul 1979 |
| 270 | Tredegar Properties, Inc. | | Oil Operator | Jun 1990 |
| 271 | Trek Resources, Inc. | Dallas, TX 75207 | Oil & Gas Operator | Jun 2025 |
| 272 | Trendsetter Production Co, Inc | | Oil & Gas Operator | Jul 2008 |
| 273 | Tri Investment Company | | Oil Operator | Mar 1980 |
| 274 | Tri-C Resources, Inc. | Houston, TX 77024 | Oil & Gas Operator | Aug 2009 |
| 275 | Tri-C Resources, LLC | Houston, TX 77024 | Oil & Gas Operator | Jun 2025 |
| 276 | Tri-Par Exploration, Inc. | | Oil Operator | Oct 2001 |
| 277 | Tri-Production Company | | Oil Operator | Apr 1994 |
| 278 | Tri-State Exploration & Prod Inc | Marshall, TX 75671 | Oil & Gas Operator | Aug 2003 |
| 279 | Tri-State Sales & Production | Rodessa, LA 71069 | Oil & Gas Operator | Dec 2008 |
| 280 | Tri-Union Development Corp. | Houston, TX 77002 | Oil & Gas Operator | Jun 2025 |
| 281 | Triad Energy Corp. Of Texas | Houston, TX 77057-2696 | Oil & Gas Operator | Sep 2014 |
| 282 | Triad Resources Inc | Spring, TX 77389 | Oil & Gas Operator | Dec 2020 |
| 283 | Triangle Oil & G G Cornwell | | Oil & Gas Operator | Nov 1981 |
| 284 | Triangle Oil Of Hosston | | Oil Operator | Jul 2014 |
| 285 | Triangle Oil Producers, Inc. | | Oil & Gas Operator | Jun 1998 |
| 286 | Tribal Oil Company | | Oil & Gas Operator | Dec 1981 |
| 287 | Tricentrol Resources Inc | Englewood, CO 80111 | Oil & Gas Operator | Jun 1984 |
| 288 | Trich Production, Inc. | Longview, TX 75606 | Oil & Gas Operator | Jan 2025 |
| 289 | Trichel Contracting Company | | Oil & Gas Operator | Sep 1987 |
| 290 | Trickle Down Oil, Inc. | | Oil & Gas Operator | Feb 2016 |
| 291 | Trico Energy Corporation | | Oil Operator | May 1984 |
| 292 | Trico Oil & Gas Inc. | Kilgore, TX 75662 | Oil & Gas Operator | Jun 2025 |
| 293 | Trico Oil Co., Inc. | | Gas Operator | Nov 1978 |
| 294 | Trident Oil And Gas Corp. | | Oil & Gas Operator | Sep 2000 |
| 295 | Trigon Exploration, Inc. | | Oil & Gas Operator | Jan 1999 |
| 296 | Trinidad Petroleum Corporation | | Oil & Gas Operator | Apr 1990 |
| 297 | Trinity Operating (Usg), LLC | Houston, TX 77002 | Oil & Gas Operator | Jun 2025 |
| 298 | Trinity Resources, Inc. | Houston, TX 77277 | Oil & Gas Operator | May 2020 |
| 299 | Trinity River Energy Oper, LLC | Houston, TX 77008 | Oil & Gas Operator | May 2018 |
| 300 | Triple J Investments Inc | Longview, TX 75606 | Oil & Gas Operator | Feb 2023 |