| 301 | R. K. G. Engineering, Inc. | Odessa, TX 79760 | Oil & Gas Operator | Mar 2026 |
| 302 | Ranger O & G Operating, LLC | Houston, TX 77057 | Oil & Gas Operator | Mar 2026 |
| 303 | Red Byrd Oil, LLC | Crystal City, TX 78839 | Oil Operator | Mar 2026 |
| 304 | Red Horse Petroleum | Dallas, TX 75240 | Oil & Gas Operator | Mar 2026 |
| 305 | Redemption Oil & Gas, LLC | San Antonio, TX 78232 | Oil & Gas Operator | Jul 2024 |
| 306 | Reh Energy, Inc. | Corpus Chrsti, TX 78413 | Oil & Gas Operator | Mar 2026 |
| 307 | Remora Operating LLC | Houston, TX 77056 | Oil & Gas Operator | Mar 2026 |
| 308 | Remuda Operating Company | Midland, TX 79711 | Oil & Gas Operator | Mar 2026 |
| 309 | Republic Resources, LLC. | San Antonio, TX 78212 | Oil & Gas Operator | Mar 2026 |
| 310 | Richman Petroleum Corp. | Grapevine, TX 76051 | Oil & Gas Operator | Jul 2006 |
| 311 | Riley Exploration, LLC | Blanchard, OK 73010 | Oil & Gas Operator | Mar 2026 |
| 312 | Rim Operating, Inc. | Englewood, CO 80112 | Oil & Gas Operator | Mar 2026 |
| 313 | Rio Bravo Royalty Co. | Bandera, TX 78003 | Oil & Gas Operator | Aug 2003 |
| 314 | Rio Exploration Company | San Antonio, TX 78209 | Gas Operator | Dec 2005 |
| 315 | Rio-Tex, Inc. | San Antonio, TX 78217 | Oil & Gas Operator | Mar 2026 |
| 316 | Rocc Operating, LLC | Houston, TX 77084 | Oil & Gas Operator | Mar 2026 |
| 317 | Rockford Energy Partners II, LLC | Tulsa, OK 74103 | Oil & Gas Operator | Sep 2007 |
| 318 | Rockport Georgetown Holdings,LP | Bellaire, TX 77401 | Oil & Gas Operator | Nov 2007 |
| 319 | Rod Oil & Gas LTD. | Houston, TX 77261 | Oil & Gas Operator | Jun 1995 |
| 320 | Roma Oil And Gas, Inc. | San Antonio, TX 78209 | Oil & Gas Operator | Mar 2026 |
| 321 | Rosetta Resources Operating LP | San Antonio, TX 78216 | Oil & Gas Operator | Mar 2026 |
| 322 | Rosewood Resources Inc | Dallas, TX 75201 | Oil & Gas Operator | Mar 2026 |
| 323 | Royal Oil & Gas Corp. | Indiana, PA 15701 | Oil & Gas Operator | Apr 2014 |
| 324 | Royal Production Company, Inc. | Corpus Chrsti, TX 78401 | Oil & Gas Operator | Mar 2026 |
| 325 | Royal Texan Resources Co. | Breckenridge, TX 76424 | Oil & Gas Operator | Mar 2026 |
| 326 | S & J Operating Company | Wichita Falls, TX 76301 | Oil & Gas Operator | Mar 2015 |
| 327 | Sabco Operating Company | Houston, TX 77056 | Oil & Gas Operator | Oct 2011 |
| 328 | Sabco Operating Company, LLC | Houston, TX 77056 | Oil & Gas Operator | Jun 2018 |
| 329 | Sabinal Resources, Inc. | Kingwood, TX 77339 | Oil & Gas Operator | Mar 2026 |
| 330 | Sabine Oil & Gas Corporation | Houston, TX 77002 | Oil & Gas Operator | Mar 2026 |
| 331 | Sage Energy Company | San Antonio, TX 78215 | Oil & Gas Operator | Mar 2026 |
| 332 | San Antonio Gas & Oil, Inc. | San Antonio, TX 78209 | Oil & Gas Operator | Feb 2000 |
| 333 | San Patricio Corporation | Dinero, TX 78350 | Oil & Gas Operator | Sep 2003 |
| 334 | Sanchez Oil & Gas Corporation | Houston, TX 77056 | Oil & Gas Operator | Mar 2026 |
| 335 | Sanchez-O'Brien Oil & Gas Corp | Houston, TX 77057 | Oil & Gas Operator | May 1998 |
| 336 | Sandia Energy Corporation-NM | Holdenville, OK 74848 | Oil & Gas Operator | Aug 2003 |
| 337 | Sandia Operating Corp. | San Antonio, TX 78270 | Oil & Gas Operator | May 2010 |
| 338 | Saxet Energy, LTD. | Houston, TX 77057 | Oil & Gas Operator | Mar 2004 |
| 339 | Saxet Petroleum, Inc. | Houston, TX 77057 | Oil & Gas Operator | Mar 2026 |
| 340 | Scully Energy Corporation | Salado, TX 76571 | Oil & Gas Operator | Mar 2012 |
| 341 | Se USA Operating, Inc. | Houston, TX 77002 | Oil & Gas Operator | Dec 2009 |
| 342 | Sea Eagle Ford, LLC | Denver, CO 80265 | Oil & Gas Operator | Jun 2022 |
| 343 | Seago Petroleum, Inc. | Abilene, TX 79606 | Oil & Gas Operator | Mar 2026 |
| 344 | Seagull Operating Co., Inc. | Shreveport, LA 71101 | Oil & Gas Operator | Jan 2025 |
| 345 | Sedco Resources Inc | Kerrville, TX 78029 | Oil & Gas Operator | Mar 2026 |
| 346 | Seismotech Energy, Incorporated | Plano, TX 75075 | Oil & Gas Operator | Aug 2003 |
| 347 | Senora Resources, Inc. | Dime Box, TX 77853 | Oil & Gas Operator | Mar 2026 |
| 348 | Shell Western E&P | Houston, TX 77001 | Oil & Gas Operator | Mar 2026 |
| 349 | Shield Petroleum | College Sta, TX 77845 | Oil & Gas Operator | Mar 2026 |
| 350 | Showdown Energy Corporation | Dallas, TX 75230 | Oil & Gas Operator | Aug 2003 |
| 351 | Silver Hill Energy Operating, LLC | Dallas, TX 75201 | Oil & Gas Operator | Mar 2026 |
| 352 | Silverbow Resources Oper, LLC | Houston, TX 77002 | Oil & Gas Operator | Mar 2026 |
| 353 | SM Energy Company | Midland, TX 79707 | Oil & Gas Operator | Mar 2026 |
| 354 | SN Ef Maverick, LLC | Houston, TX 77002 | Oil & Gas Operator | Aug 2023 |
| 355 | SN Operating, LLC | Houston, TX 77002 | Oil & Gas Operator | May 2023 |
| 356 | Solano Gas Processing, Inc. | Austin, TX 78759 | Oil & Gas Operator | Aug 1998 |
| 357 | South Oil, Inc. | Houston, TX 77057 | Oil & Gas Operator | Nov 2018 |
| 358 | Southwest Oil & Land, Inc. | Corpus Chrsti, TX 78460 | Oil & Gas Operator | Dec 1999 |
| 359 | Spri Oil & Gas, LLC | Houston, TX 77090 | Oil & Gas Operator | Mar 2020 |
| 360 | Spur Operating Co. | Austin, TX 78701 | Oil & Gas Operator | Mar 2026 |
| 361 | St. Mary Land & Exploration Co | Denver, CO 80201 | Oil & Gas Operator | Jun 2010 |
| 362 | Stacha, Eddy A. | Rice, TX 75155 | Oil & Gas Operator | Mar 2026 |
| 363 | Stalking Horse Energy, Limited Liability Company | Houston, TX 77062 | Oil & Gas Operator | Mar 2026 |
| 364 | Starrak Operating Company, Inc. | Midland, TX 79706 | Oil & Gas Operator | Jun 1999 |
| 365 | Stephens & Johnson Operating Co. | Wichita Falls, TX 76307 | Oil & Gas Operator | Mar 2026 |
| 366 | Stephens Production Company | The Woodlands, TX 77381 | Oil & Gas Operator | Jan 2026 |
| 367 | Stonegate Operators, Inc. | Addison, TX 75001 | Oil Operator | Mar 2026 |
| 368 | Stonegate Production Company,LLC | Houston, TX 77024 | Oil & Gas Operator | Mar 2026 |
| 369 | STP Production, LLC | Corpus Chrsti, TX 78411 | Oil & Gas Operator | Mar 2026 |
| 370 | Sue-Ann Operating, L.C. | Victoria, TX 77903 | Oil & Gas Operator | Mar 2026 |
| 371 | Sue-Ann Production Company | Victoria, TX 77903 | Oil & Gas Operator | Mar 2008 |
| 372 | Suemaur Exploration, Inc. | Corpus Chrsti, TX 78470 | Oil & Gas Operator | Mar 2008 |
| 373 | Sutton Producing Corp. | San Antonio, TX 78270 | Oil & Gas Operator | Mar 2026 |
| 374 | Swift Energy Company | Houston, TX 77060 | Oil & Gas Operator | Mar 2021 |
| 375 | Swift Energy Operating, LLC | Houston, TX 77079 | Oil & Gas Operator | Jun 2017 |
| 376 | Tam2 Squared Operating, LLC | Rockwall, TX 75032 | Oil & Gas Operator | Mar 2026 |
| 377 | Targa Pipeline Mid-Continent LLC | Sulphur, LA 70665 | Oil & Gas Operator | Jun 2018 |
| 378 | TBM Catarina, LLC | Fort Worth, TX 76102 | Oil & Gas Operator | Mar 2026 |
| 379 | TC Oil And Gas, LLC | Denton, TX 76205 | Oil Operator | Mar 2026 |
| 380 | TD Natural Resources LLC | Cuero, TX 77954 | Oil & Gas Operator | Mar 2026 |
| 381 | Texakoma Oil & Gas Corp | Dallas, TX 75240 | Oil & Gas Operator | Sep 2014 |
| 382 | Texan Production Company, Inc. | Canyon Lake, TX 78133 | Oil & Gas Operator | Mar 2026 |
| 383 | Texas American Resources Company | Austin, TX 78701 | Oil & Gas Operator | Mar 2026 |
| 384 | Texas International Oper., LLC | Fort Worth, TX 76102 | Oil & Gas Operator | Dec 2013 |
| 385 | Texas Lone Star Petroleum Corp. | Corpus Chrsti, TX 78401 | Oil & Gas Operator | Dec 2013 |
| 386 | Texas Southern Petroleum Corp. | Corpus Chrsti, TX 78410 | Oil & Gas Operator | Mar 2026 |
| 387 | Texas, Les & Co. | Brenham, TX 77833 | Oil & Gas Operator | Mar 2026 |
| 388 | Texokan Operating, Inc. | Dallas, TX 75206 | Oil & Gas Operator | Mar 2026 |
| 389 | Texowa, LLC | Roanoke, TX 76262 | Oil Operator | Mar 2026 |
| 390 | Thalmann Oil Field Service, Inc. | Carrizo SPGS, TX 78834 | Oil & Gas Operator | Mar 2008 |
| 391 | Thalmann Oilfield | Carrizo SPGS, TX 78834 | Oil Operator | Mar 2026 |
| 392 | Thalmann, David Vac Service Inc | Carrizo SPGS, TX 78834 | Oil & Gas Operator | Mar 2026 |
| 393 | Tidal Petroleum, Inc. | Schertz, TX 78154 | Oil & Gas Operator | Mar 2026 |
| 394 | Tide West Oil Company | Tulsa, OK 74136 | Oil & Gas Operator | Mar 2021 |
| 395 | Tidelands Gas Corporation | Flower Mound, TX 75028 | Oil & Gas Operator | Sep 2000 |
| 396 | Tipperary Oil & Gas Corporation | Denver, CO 80202 | Oil & Gas Operator | May 2014 |
| 397 | Total Minatome Corporation | Houston, TX 77210 | Oil & Gas Operator | Dec 1998 |
| 398 | Tracker Oil & Gas, Inc. | Bastrop, TX 78602 | Oil & Gas Operator | Mar 2026 |
| 399 | Tradition Resources Oper, LLC | Houston, TX 77002 | Oil & Gas Operator | Jul 2017 |
| 400 | Trailblazer Energy Resources, LLC | Tulsa, OK 74136 | Oil & Gas Operator | Mar 2026 |