| 301 | Patterson Petroleum LP | Snyder, TX 79550 | Oil & Gas Operator | Mar 2008 |
| 302 | Patterson Petroleum, Inc. | Snyder, TX 79550 | Oil & Gas Operator | Feb 2000 |
| 303 | Pecos Petroleum Company | Houston, TX 77057 | Oil & Gas Operator | Oct 1999 |
| 304 | Pegasus Operating, Inc. | Coldspring, TX 77331 | Oil & Gas Operator | Mar 2025 |
| 305 | Peles, LLC | Houston, TX 77057 | Oil & Gas Operator | Mar 2025 |
| 306 | Petro-Smith Operating LLC | Houston, TX 77010 | Oil & Gas Operator | Mar 2025 |
| 307 | Petroleum Management, Inc. | Corpus Chrsti, TX 78471 | Oil & Gas Operator | Mar 2025 |
| 308 | Petroleum Resource Management Co | Fort Worth, TX 76107 | Oil & Gas Operator | Jan 2024 |
| 309 | Petrosearch Operating Co, LLC | Denver, CO 80202 | Oil & Gas Operator | Mar 2025 |
| 310 | Petrotex, Inc. | Abilene, TX 79604 | Oil & Gas Operator | Aug 2003 |
| 311 | Phillips Petroleum Company | Houston, TX 77251 | Oil & Gas Operator | Mar 2013 |
| 312 | Pitchfork Oil & Gas, Inc. | Orchard, TX 77464 | Oil & Gas Operator | Mar 2025 |
| 313 | Placid Oil Company | Houston, TX 77227 | Oil & Gas Operator | Mar 2008 |
| 314 | Plantation Operating Co., Inc. | Holliday, TX 76366 | Oil & Gas Operator | Mar 2025 |
| 315 | Pride Energy Company | Tulsa, OK 74170 | Oil & Gas Operator | Mar 2025 |
| 316 | Primal Energy Corporation | The Woodlands, TX 77380 | Oil & Gas Operator | Mar 2025 |
| 317 | Prime Natural Resources, Inc. | Houston, TX 77042 | Oil & Gas Operator | Jun 2007 |
| 318 | Prime Operating Company | Houston, TX 77024 | Oil & Gas Operator | Mar 2025 |
| 319 | Producers Energy Corporation | Houston, TX 77002 | Oil & Gas Operator | Aug 2000 |
| 320 | Proex Energy Management, L.L.C. | Spring, TX 77386 | Oil & Gas Operator | Mar 2025 |
| 321 | Proline Energy Resources Inc | Sugar Land, TX 77479 | Oil & Gas Operator | Mar 2025 |
| 322 | Property Development Group, Inc. | San Antonio, TX 78212 | Oil & Gas Operator | Mar 2025 |
| 323 | Pure Resources, L.P. | Midland, TX 79701 | Oil & Gas Operator | Mar 2006 |
| 324 | Quicksilver Resources Inc | Fort Worth, TX 76102 | Oil & Gas Operator | Mar 2018 |
| 325 | Quintana Pet. Corp. | Refugio, TX 78377 | Oil & Gas Operator | Dec 2000 |
| 326 | Raptor Resources, Inc. | Austin, TX 78701 | Oil & Gas Operator | Mar 2025 |
| 327 | Red Shell Inc | Dale, TX 78616 | Oil & Gas Operator | Mar 2025 |
| 328 | Redman Operating Company | Houston, TX 77042 | Oil & Gas Operator | May 2008 |
| 329 | Redwood Operating, Inc. | Houston, TX 77058 | Oil & Gas Operator | Mar 2025 |
| 330 | Reo Operating LLC | Austin, TX 78747 | Oil & Gas Operator | Mar 2025 |
| 331 | Resaca Resources, L.L.C. | Austin, TX 78746 | Oil & Gas Operator | Mar 2025 |
| 332 | Ricochet Energy, Inc. | San Antonio, TX 78258 | Oil & Gas Operator | Mar 2025 |
| 333 | Rio Bravo Expl. & Prod. Co. | Houston, TX 77055 | Oil & Gas Operator | Apr 2020 |
| 334 | Rio Bravo Oil Company | The Woodlands, TX 77381 | Oil & Gas Operator | Feb 2002 |
| 335 | Rme Austin Chalk Company | Houston, TX 77251 | Oil & Gas Operator | Nov 2002 |
| 336 | Rocinante | Houston, TX 77058 | Oil Operator | Mar 2025 |
| 337 | Rockwell Energy, LLC | Spring, TX 77386 | Oil & Gas Operator | Sep 2014 |
| 338 | Rodeo Resources, L.L.C. | Houston, TX 77079 | Oil & Gas Operator | Dec 2024 |
| 339 | Rodessa Operating Company | Corpus Chrsti, TX 78426 | Oil & Gas Operator | Mar 2025 |
| 340 | Roy Jackson Energy Operating, LLC | Midland, TX 79701 | Oil & Gas Operator | Mar 2025 |
| 341 | Royal Production Company, Inc. | Corpus Chrsti, TX 78401 | Oil & Gas Operator | Mar 2025 |
| 342 | S.O.C. Investors, Inc. | San Antonio, TX 78209 | Oil & Gas Operator | Mar 2025 |
| 343 | Sabco Operating Company | Houston, TX 77056 | Oil & Gas Operator | Oct 2011 |
| 344 | Samedan Oil Corporation | Houston, TX 77067 | Oil & Gas Operator | Dec 2019 |
| 345 | Sanchez Oil & Gas Corporation | Houston, TX 77056 | Oil & Gas Operator | Mar 2025 |
| 346 | Sandalwood Exploration, L.P. | Houston, TX 77056 | Oil & Gas Operator | Mar 2025 |
| 347 | Sawtooth Operating Co., Inc. | Houston, TX 77024 | Oil & Gas Operator | Mar 2025 |
| 348 | Sawtooth, Inc. | Houston, TX 77024 | Oil & Gas Operator | Dec 2013 |
| 349 | Saxet Exploration Ent. Co., Inc. | Fulshear, TX 77441 | Oil Operator | Mar 2025 |
| 350 | Scoggins Oil & Gas Co. | Seabrook, TX 77586 | Oil & Gas Operator | Jun 2000 |
| 351 | Seismic Investment Group, Inc. | Houston, TX 77055 | Oil & Gas Operator | Jun 2008 |
| 352 | Senora Resources, Inc. | Dime Box, TX 77853 | Oil & Gas Operator | Mar 2025 |
| 353 | Shell Trading Us Company | Houston, TX 77210 | Oil & Gas Operator | Dec 2024 |
| 354 | Shoreham Oil & Gas Company, Inc. | Katy, TX 77492 | Oil & Gas Operator | Mar 2025 |
| 355 | Silverbrook Operating II LLC | Barker, TX 77413 | Oil Operator | Mar 2025 |
| 356 | Silverbrook Operating, LLC | Barker, TX 77413 | Oil Operator | Mar 2025 |
| 357 | Smith Petroleum Company | Spring, TX 77389 | Oil & Gas Operator | Mar 2025 |
| 358 | Smyth Oil Corporation | Houston, TX 77002 | Oil & Gas Operator | Oct 2003 |
| 359 | Sonat Exploration Co. - Houston | Houston, TX 77251 | Oil & Gas Operator | Dec 1999 |
| 360 | Southeastern Pipe Line Company | Tyler, TX 75711 | Oil & Gas Operator | Dec 2020 |
| 361 | Southern Resource Company | Corpus Chrsti, TX 78404 | Oil & Gas Operator | Mar 2022 |
| 362 | SSC, Inc. | Lubbock, TX 79408 | Oil & Gas Operator | Mar 2025 |
| 363 | Stealth Onsite Solutions LLC | Pasadena, TX 77505 | Oil Operator | Mar 2025 |
| 364 | Stoneham Oil Company | Houston, TX 77002 | Oil & Gas Operator | Sep 1995 |
| 365 | Sue-Ann Operating, L.C. | Victoria, TX 77903 | Oil & Gas Operator | Mar 2025 |
| 366 | Sue-Ann Production Company | Victoria, TX 77903 | Oil & Gas Operator | Mar 2008 |
| 367 | Synergy Oil & Gas, L.P. | Houston, TX 77024 | Oil & Gas Operator | May 2012 |
| 368 | Tartan Resources Corporation | Houston, TX 77251 | Oil & Gas Operator | Oct 1995 |
| 369 | Tenex Corporation | Houston, TX 77227 | Oil & Gas Operator | Dec 2007 |
| 370 | Texaco E & P Inc | Houston, TX 77099 | Oil & Gas Operator | Mar 2025 |
| 371 | Texakoma E & P, LLC | Plano, TX 75024 | Oil & Gas Operator | Mar 2025 |
| 372 | Texakoma Oil & Gas Corp | Dallas, TX 75240 | Oil & Gas Operator | Sep 2014 |
| 373 | Texakoma Operating, L.P. | Plano, TX 75024 | Oil & Gas Operator | Jan 2025 |
| 374 | Texana Operating Company | Houston, TX 77090 | Oil & Gas Operator | Mar 2025 |
| 375 | Texas Onshore Energy, Inc. | Austin, TX 78704 | Oil & Gas Operator | Mar 2025 |
| 376 | Texas Petroleum Investment Company | Houston, TX 77057 | Oil & Gas Operator | Mar 2025 |
| 377 | Texas Secondary Oil Corporation | Devine, TX 78016 | Oil & Gas Operator | Mar 2025 |
| 378 | Texron Operating, LLC | Bulverde, TX 78163 | Oil & Gas Operator | Mar 2025 |
| 379 | Texstar North America, Inc. | Waynesboro, MS 39367 | Oil & Gas Operator | Aug 1994 |
| 380 | Thorp Petroleum Corporation | Houston, TX 77002 | Oil & Gas Operator | Feb 2014 |
| 381 | Tidal Petroleum, Inc. | Schertz, TX 78154 | Oil & Gas Operator | Mar 2025 |
| 382 | Titan Petroleum, Inc. | Tomball, TX 77375 | Oil & Gas Operator | Nov 2004 |
| 383 | Tracer Energy, Inc. | Graham, TX 76450 | Oil & Gas Operator | Nov 1998 |
| 384 | Trans-Pecos Resources, Inc. | Houston, TX 77056 | Oil & Gas Operator | Mar 2025 |
| 385 | Tritex Production Co. | Iowa Park, TX 76367 | Oil & Gas Operator | Jan 2013 |
| 386 | Truth Resources LP | Houston, TX 77090 | Oil Operator | Sep 2021 |
| 387 | Tucker Operating Co., Inc. | Victoria, TX 77903 | Oil & Gas Operator | Mar 2025 |
| 388 | Tuskar (Texas), Inc. | Nichols Hill, OK 73116 | Oil & Gas Operator | Jan 2016 |
| 389 | Union Crude Operating Co. | Baytown, TX 77521 | Oil Operator | Aug 2003 |
| 390 | Union Pacific Austin Chalk Co. | Fort Worth, TX 76101 | Oil & Gas Operator | Jan 2001 |
| 391 | Union Pacific Resources Co. | Fort Worth, TX 76101 | Oil & Gas Operator | Sep 2002 |
| 392 | Valence Operating Company | Kingwood, TX 77339 | Oil & Gas Operator | Mar 2025 |
| 393 | Vanco Oil & Gas Corp. | Abilene, TX 79604 | Oil & Gas Operator | Mar 2025 |
| 394 | Vaquero Operating | FT Stockton, TX 79735 | Oil & Gas Operator | Mar 2025 |
| 395 | Venus Oil Company | San Antonio, TX 78209 | Oil & Gas Operator | Dec 2002 |
| 396 | Viceroy Petroleum, LP | College Sta, TX 77845 | Oil & Gas Operator | Mar 2025 |
| 397 | Vintage Petroleum, Inc. | Houston, TX 77046 | Oil & Gas Operator | Dec 2024 |
| 398 | Vintage Petroleum, LLC | Houston, TX 77210 | Oil & Gas Operator | Dec 2019 |
| 399 | Virlar Exploration, Inc. | Houston, TX 77227 | Oil & Gas Operator | Aug 1995 |
| 400 | Wallis Energy, Inc. | Austin, TX 78746 | Oil & Gas Operator | Mar 2025 |