| 301 | Texas Utilities Mining Co. | Dallas, TX 75201 | Oil & Gas Operator | May 1995 |
| 302 | Texas Valley Oil & Gas, LLC | Hidalgo, TX 78557 | Oil Operator | Nov 2024 |
| 303 | Texas Vanguard Oil Company | Austin, TX 78720 | Oil & Gas Operator | Jan 2014 |
| 304 | Texas Western Energy Corporation | Portland, TX 78374 | Oil & Gas Operator | Nov 2002 |
| 305 | Texas Western Oil Company | Sioux Falls, SD 57109 | Oil & Gas Operator | Sep 2013 |
| 306 | Texas, Les & Co. | Austin, TX 78746 | Oil & Gas Operator | Nov 2024 |
| 307 | Texas, Les C., LTD. | Houston, TX 77095 | Oil & Gas Operator | Dec 2006 |
| 308 | Texas-Australia Power Inc. | Wichita Falls, TX 76302 | Oil & Gas Operator | Dec 2011 |
| 309 | Texas-Ohio Producing Company | Spring, TX 77383 | Oil & Gas Operator | Jul 1995 |
| 310 | Texasgulf Inc. | Newgulf, TX 77462 | Oil & Gas Operator | Jul 1994 |
| 311 | Texcal Energy (GP) LLC | Denver, CO 80202 | Oil & Gas Operator | Mar 2016 |
| 312 | Texcal Oil Co | Cuero, TX 77954 | Oil & Gas Operator | Feb 2006 |
| 313 | Texcal Oil Inc. | Vidor, TX 77662 | Oil & Gas Operator | Jun 1999 |
| 314 | Texcal Resources, Inc. | Plano, TX 75094 | Oil & Gas Operator | Apr 1994 |
| 315 | Texcel Exploration, Inc. | Colorado SPGS, CO 80960 | Oil & Gas Operator | Nov 2024 |
| 316 | Texdon Operating | Breckenridge, TX 76424 | Oil & Gas Operator | Jun 2005 |
| 317 | Texeast Operating Co., Inc. | Farmers BRNCH, TX 75234 | Oil Operator | Nov 2024 |
| 318 | Texegy Operating Company LLC | Corpus Chrsti, TX 78401 | Oil & Gas Operator | Jun 2024 |
| 319 | Texian Operating Company, LLC | Irving, TX 75063 | Oil & Gas Operator | Nov 2024 |
| 320 | Texical, Inc. | Katy, TX 77491 | Oil & Gas Operator | Nov 2024 |
| 321 | Texican Crude & Hydrocarbons LLC | Houston, TX 77002 | Oil Operator | Sep 2023 |
| 322 | Texinia Corp | Dallas, TX 75201 | Oil & Gas Operator | Jun 2015 |
| 323 | Texla Energy Products LLC | Houston, TX 77002 | Oil Operator | Sep 2020 |
| 324 | Texla Operating Co | Jonesville, TX 75659 | Oil & Gas Operator | Nov 2024 |
| 325 | Texlan Oil Company, Inc. | Tyler, TX 75701 | Oil & Gas Operator | Nov 1994 |
| 326 | Texlan Oil Company, L.C. | Tyler, TX 75711 | Oil & Gas Operator | Aug 2003 |
| 327 | Texland Petroleum Inc | Fort Worth, TX 76102 | Oil & Gas Operator | Apr 2007 |
| 328 | Texland Petroleum, L.P. | Fort Worth, TX 76107 | Oil & Gas Operator | Nov 2024 |
| 329 | Texland Petroleum-Hobbs, L.L.C. | Fort Worth, TX 76102 | Oil & Gas Operator | Sep 2024 |
| 330 | Texland-Rector & Schumacher | Fort Worth, TX 76102 | Oil & Gas Operator | Nov 2000 |
| 331 | Texland/JMC Joint Venture | Fort Worth, TX 76102 | Oil & Gas Operator | Dec 2002 |
| 332 | Texlark Exploration Company, Inc | Plano, TX 75074 | Oil & Gas Operator | Sep 2001 |
| 333 | Texokan Energy Corporation | Scroggins, TX 75480 | Oil & Gas Operator | Jul 1996 |
| 334 | Texokan Operating, Inc. | Dallas, TX 75206 | Oil & Gas Operator | Nov 2024 |
| 335 | Texoma Legacy Properties, LLC | Holliday, TX 76366 | Oil Operator | Dec 2023 |
| 336 | Texoma Oil Tools, Inc. | Wichita Falls, TX 76308 | Oil & Gas Operator | Nov 2024 |
| 337 | Texon Oil Company, Inc. | Midland, TX 79710 | Oil & Gas Operator | Apr 2023 |
| 338 | Texona Petroleum Corporation | Houston, TX 77084 | Oil & Gas Operator | Aug 2003 |
| 339 | Texowa, LLC | Roanoke, TX 76262 | Oil Operator | Nov 2024 |
| 340 | Texoz E&P I, Inc. | Houston, TX 77077 | Oil & Gas Operator | Nov 2024 |
| 341 | Texploration | Rosharon, TX 77583 | Oil Operator | Nov 2024 |
| 342 | Texron Operating, LLC | Bulverde, TX 78163 | Oil & Gas Operator | Nov 2024 |
| 343 | Texstar Drilling, Inc. | Houston, TX 77084 | Oil & Gas Operator | Nov 2024 |
| 344 | Texstar North America, Inc. | Waynesboro, MS 39367 | Oil & Gas Operator | Aug 1994 |
| 345 | Texstar Oil & Gas, LLC | Luling, TX 78648 | Oil & Gas Operator | Nov 2024 |
| 346 | Texstar Operating Inc. | Lubbock, TX 79423 | Oil & Gas Operator | Nov 2024 |
| 347 | Texstar Petroleum, Inc. | Houston, TX 77002 | Oil & Gas Operator | Nov 2000 |
| 348 | Texsun Operating Company Limited | Abilene, TX 79601 | Oil & Gas Operator | Mar 1996 |
| 349 | Textroleum Production, Inc. | Lubbock, TX 79452 | Oil & Gas Operator | Mar 2008 |
| 350 | Textron Southwest Inc. | Henderson, TX 75654 | Oil & Gas Operator | Nov 2024 |
| 351 | Textron Southwest L.L.C. | Addison, TX 75001 | Oil & Gas Operator | Oct 2004 |
| 352 | Texu Inc. | Bridgeport, TX 76426 | Oil & Gas Operator | Jan 2007 |
| 353 | Texxol Operating Company, Inc. | Fort Worth, TX 76108 | Oil & Gas Operator | Nov 2024 |
| 354 | Texxon Resources, Inc. | Winter Park, FL 32792 | Oil & Gas Operator | Nov 2024 |
| 355 | Texzona Oil & Gas, Inc. | Abilene, TX 79608 | Oil & Gas Operator | Dec 1997 |
| 356 | TFX, Inc. | Graham, TX 76450 | Oil & Gas Operator | Oct 2019 |
| 357 | TGNR East Texas II LLC | Houston, TX 77002 | Oil & Gas Operator | Nov 2024 |
| 358 | TGNR East Texas LLC | Houston, TX 77002 | Oil & Gas Operator | Nov 2024 |
| 359 | TGNR Gulf Coast LLC | Houston, TX 77002 | Oil & Gas Operator | Nov 2024 |
| 360 | TGNR TVL LLC | Houston, TX 77002 | Oil & Gas Operator | Jun 2024 |
| 361 | Tgo Operating, LLC | Midland, TX 79705 | Oil & Gas Operator | Dec 2008 |
| 362 | TGX Corporation | Houston, TX 77002 | Oil & Gas Operator | Sep 2004 |
| 363 | Thagard Trust | Midland, TX 79702 | Gas Operator | Nov 2024 |
| 364 | Thalmann Oil Field Service, Inc. | Carrizo SPGS, TX 78834 | Oil & Gas Operator | Mar 2008 |
| 365 | Thalmann Oilfield | Carrizo SPGS, TX 78834 | Oil Operator | Nov 2024 |
| 366 | Thalmann, David Vac Service Inc | Carrizo SPGS, TX 78834 | Oil & Gas Operator | Nov 2024 |
| 367 | Tharp Operating Company | Houston, TX 77070 | Oil & Gas Operator | Nov 2014 |
| 368 | The Brogdon Company, Inc. | Graham, TX 76450 | Oil & Gas Operator | May 2024 |
| 369 | The Cornell Corporation | Fort Worth, TX 76109 | Oil & Gas Operator | Sep 1993 |
| 370 | The Houston Exploration Company | Houston, TX 77002 | Oil & Gas Operator | Apr 2017 |
| 371 | The Operating Co. | Pampa, TX 79065 | Oil & Gas Operator | Sep 2007 |
| 372 | The Quintin Little Company Inc | Ardmore, OK 73401 | Oil & Gas Operator | Sep 2024 |
| 373 | The Termo Company | Long Beach, CA 90801 | Oil & Gas Operator | Sep 2024 |
| 374 | Theisen, VIncent A. | Wilmington, DE 19807 | Oil & Gas Operator | Sep 2003 |
| 375 | Thomas Exploration & Devel., Inc | Jourdanton, TX 78026 | Oil & Gas Operator | Nov 2024 |
| 376 | Thomas Oil & Gas Company | Luling, TX 78648 | Oil & Gas Operator | Aug 2003 |
| 377 | Thomas Oil And Gas Inc. | San Angelo, TX 76906 | Oil & Gas Operator | May 2019 |
| 378 | Thomas Operating LTD. Co. | Dallas, TX 75220 | Oil & Gas Operator | Nov 2024 |
| 379 | Thomas Production | Electra, TX 76360 | Oil & Gas Operator | Mar 2015 |
| 380 | Thomas Resources Corporation | Monahans, TX 79756 | Oil Operator | Mar 2008 |
| 381 | Thomas, B. K. | Plano, TX 75093 | Oil & Gas Operator | Jan 2008 |
| 382 | Thomas, M.A. Oil Associates | Nocona, TX 76255 | Oil & Gas Operator | Nov 2024 |
| 383 | Thomas, Mike | Nixon, TX 78140 | Oil Operator | Nov 2024 |
| 384 | Thomas, R. W. Inc. | Norman, OK 73070 | Oil & Gas Operator | Apr 2015 |
| 385 | Thomas, T. N. Oil Company | Aiken, SC 29801 | Oil & Gas Operator | Nov 2024 |
| 386 | Thompson Oil Co. | Corsicana, TX 75151 | Oil & Gas Operator | Aug 2024 |
| 387 | Thompson Operating Co. | Abernathy, TX 79311 | Oil & Gas Operator | Aug 1994 |
| 388 | Thompson, J. Cleo | Dallas, TX 75201 | Oil & Gas Operator | May 2024 |
| 389 | Thompson, Joe L., Inc. | Oklahoma City, OK 73132 | Oil & Gas Operator | Oct 2005 |
| 390 | Thompson, Mark P. | Graham, TX 76450 | Oil & Gas Operator | Nov 2024 |
| 391 | Thompson, Richard W. Inc. | Plano, TX 75024 | Oil & Gas Operator | Nov 2024 |
| 392 | Thor Operating Company | Tyler, TX 75710 | Oil & Gas Operator | Dec 1995 |
| 393 | Thor-Max Operating, Inc. | Plano, TX 75025 | Oil & Gas Operator | Nov 2024 |
| 394 | Thornberry Oilfield Service, Inc | Conroe, TX 77302 | Oil & Gas Operator | Aug 2003 |
| 395 | Thornton Oil Co. | Abilene, TX 79603 | Oil & Gas Operator | Aug 2003 |
| 396 | Thornton, Michael D. | Breckenridge, TX 76424 | Oil & Gas Operator | Nov 1995 |
| 397 | Thorp Petroleum Corporation | Houston, TX 77002 | Oil & Gas Operator | Feb 2014 |
| 398 | THP Operating LLC | Santa Anna, TX 76878 | Oil & Gas Operator | Nov 2024 |
| 399 | Thrall Operating Company, Inc. | Dallas, TX 75240 | Oil & Gas Operator | Nov 2024 |
| 400 | Thrash, Afton | Kilgore, TX 75663 | Oil & Gas Operator | Apr 1996 |