| 301 | Sonat Exploration Co. | Houston, TX 77251 | Oil & Gas Operator | Dec 2021 |
| 302 | Sonat Exploration Gom Inc. | Houston, TX 77251 | Oil & Gas Operator | Dec 1999 |
| 303 | South Oak Production Company | | Oil & Gas Operator | Jun 2010 |
| 304 | Southern Natural Gas Co | Houston, TX 77001 | Oil & Gas Operator | Dec 2011 |
| 305 | Southern Natural Gas Co, LLC | | Oil & Gas Operator | Nov 2024 |
| 306 | Spooner Petroleum Company | | Oil & Gas Operator | Nov 2024 |
| 307 | St. Mary Operating Company | Denver, CO 80203 | Oil & Gas Operator | Mar 2019 |
| 308 | Stone Petroleum Corporation | | Oil & Gas Operator | Dec 1996 |
| 309 | Strata Energy, Inc. | | Oil & Gas Operator | Sep 1983 |
| 310 | Striper Oil, Inc. | Dallas, TX 75379 | Oil & Gas Operator | Apr 2002 |
| 311 | Sue-Ann Operating, L.C. | Victoria, TX 77903 | Oil & Gas Operator | Mar 2025 |
| 312 | Sugar Bowl Gas Corp. | | Oil Operator | Dec 1983 |
| 313 | Summit Energy Company | | Oil & Gas Operator | Mar 2009 |
| 314 | Sun Exploration-Production Co. | | Oil & Gas Operator | Jan 1990 |
| 315 | Superior Oil Co. | Denver, CO 80217-5444 | Oil & Gas Operator | Feb 2001 |
| 316 | Swift Energy Company | Houston, TX 77060 | Oil & Gas Operator | Mar 2021 |
| 317 | Swift Energy Operating, LLC | Houston, TX 77079 | Oil & Gas Operator | Jun 2017 |
| 318 | T.O.I. | Midland, TX 79710 | Oil & Gas Operator | Mar 2001 |
| 319 | Talos Third Coast LLC | | Oil & Gas Operator | Dec 2024 |
| 320 | Tebco Oil & Gas | | Oil & Gas Operator | Sep 1996 |
| 321 | Tee Operating Company | | Oil & Gas Operator | Jun 1989 |
| 322 | Tellus Operating Group, LLC | | Oil & Gas Operator | Dec 2024 |
| 323 | Tenneco Oil Company | Oklahoma City, OK 73125 | Oil & Gas Operator | Dec 2024 |
| 324 | Tesla Resources, Inc. | | Oil & Gas Operator | Aug 1996 |
| 325 | Texaco E & P Inc | Houston, TX 77099 | Oil & Gas Operator | Mar 2025 |
| 326 | Texaco Inc | Kingfisher, OK 73750 | Oil & Gas Operator | Dec 2017 |
| 327 | Texaco Producing Inc. | Rock Springs, WY 82901 | Oil & Gas Operator | Dec 2000 |
| 328 | Texas Crude Exploration, Inc. | Fort Worth, TX 76116 | Oil & Gas Operator | Aug 1992 |
| 329 | Texas Energy & Environmental Inc | Houston, TX 77269 | Oil & Gas Operator | Oct 1998 |
| 330 | Texas Gas Transmission Corp. | | Oil Operator | Aug 2003 |
| 331 | Texas Petroleum Investment Company | Houston, TX 77057 | Oil & Gas Operator | Mar 2025 |
| 332 | Texasgulf Inc. | Newgulf, TX 77462 | Oil & Gas Operator | Jul 1994 |
| 333 | The Ballard & Cordell Corp | | Oil & Gas Operator | Feb 1982 |
| 334 | The Harvest Group, LLC | | Oil & Gas Operator | May 2011 |
| 335 | The Meridian Res. & Exp. LLC | | Oil & Gas Operator | Sep 2010 |
| 336 | The Stone Oil Corporation | | Oil & Gas Operator | May 1985 |
| 337 | TMR Exploration, Inc. | Bossier City, LA 71171 | Oil & Gas Operator | Mar 2025 |
| 338 | Tortuga Operating Company | Houston, TX 77055 | Oil & Gas Operator | Mar 2025 |
| 339 | Total Minatome Corporation | Houston, TX 77210 | Oil & Gas Operator | Dec 1998 |
| 340 | Triumph Energy, Inc. | Lafayette, LA 70505 | Oil & Gas Operator | Nov 2015 |
| 341 | Trunkline Gas Company | | Oil Operator | Mar 2008 |
| 342 | Tucker Operating Co., Inc. | Victoria, TX 77903 | Oil & Gas Operator | Mar 2025 |
| 343 | U S Liquids Of La., L.P. | | Oil Operator | Apr 2014 |
| 344 | Umc Petroleum Corporation | Houston, TX 77002 | Oil & Gas Operator | Mar 2015 |
| 345 | Union Exploration Partners, LTD. | | Oil & Gas Operator | Aug 1990 |
| 346 | Union Oil Co Of California | Midland, TX 79706 | Oil & Gas Operator | Jan 2022 |
| 347 | Union Texas Petroleum Corp. | Houston, TX 77252-2120 | Oil & Gas Operator | Dec 2014 |
| 348 | United Gas Pipe Line Co. | | Oil Operator | Aug 1993 |
| 349 | Unocal Exploration Corporation | | Oil & Gas Operator | May 1992 |
| 350 | Us Oil & Gas Inc | Marietta, OH 45750 | Oil & Gas Operator | Jan 2025 |
| 351 | V. E. Karnes | | Oil Operator | Jun 1989 |
| 352 | Vastar Resources Inc | Houston, TX 77253 | Oil & Gas Operator | Nov 2024 |
| 353 | Vector Energy Corporation | Houston, TX 77060 | Oil & Gas Operator | Mar 2025 |
| 354 | Ventures Oil & Gas Of La Inc. | | Oil & Gas Operator | Jun 1999 |
| 355 | Vernon E. Faulconer | | Oil & Gas Operator | Dec 1996 |
| 356 | Vernon E. Faulconer, Inc. | Tyler, TX 75711 | Oil & Gas Operator | Dec 2024 |
| 357 | Vintage Petroleum, Inc. | Houston, TX 77046 | Oil & Gas Operator | Dec 2024 |
| 358 | Vtex Energy, Inc. | Houston, TX 77057 | Oil & Gas Operator | Mar 2025 |
| 359 | W. L. Estis | | Oil & Gas Operator | Dec 1999 |
| 360 | W. W. F. Oil Corporation | | Oil & Gas Operator | Dec 1999 |
| 361 | Wapiti Operating, LLC | Houston, TX 77043 | Oil & Gas Operator | Mar 2025 |
| 362 | Watson Energy, L.L.C. | | Oil & Gas Operator | Jun 2005 |
| 363 | Weaver Exploration Company | | Oil & Gas Operator | Jun 1991 |
| 364 | Wheless Industries, Inc. | Shreveport, LA 71101-5301 | Oil & Gas Operator | Sep 2002 |
| 365 | White Oak Operating Company LLC | Houston, TX 77077 | Oil & Gas Operator | Mar 2025 |
| 366 | Whitney Oil & Gas, LLC | | Oil & Gas Operator | Jan 2025 |
| 367 | Whitton Company, Inc. | | Oil & Gas Operator | Jul 2020 |
| 368 | WHK, Inc. | | Oil & Gas Operator | Oct 1993 |
| 369 | WRT Energy Corporation | Oklahoma City, OK 73118 | Oil & Gas Operator | May 1998 |
| 370 | XTO Energy Inc. | Spring, TX 77389 | Oil & Gas Operator | Mar 2025 |
| 371 | Yasny Corporation | | Oil Operator | Nov 1991 |
| 372 | Yuma Petroleum Company | Houston, TX 77027 | Oil & Gas Operator | Aug 2002 |
| 373 | Zenergy Inc | Tulsa, OK 74136 | Oil & Gas Operator | Jan 2025 |
| 374 | Zilkha Energy Company | Houston, TX 77046 | Oil & Gas Operator | Oct 2002 |
| 375 | Zinke & Trumbo, Inc. | Tulsa, OK 74136 | Oil & Gas Operator | Mar 2007 |