| 301 | Noxxe Oil And Gas, LLC | Houston, TX 77269 | Oil & Gas Operator | Aug 2025 |
| 302 | Nueces Petroleum Corporation | Sugar Land, TX 77496 | Oil Operator | Aug 2025 |
| 303 | O'Sand Production, Inc. | Tomball, TX 77377 | Oil & Gas Operator | Aug 2003 |
| 304 | Ocean Energy, Inc. | Houston, TX 77002 | Oil & Gas Operator | Aug 2003 |
| 305 | Oil Lease Operating Co. | Coldspring, TX 77331 | Oil & Gas Operator | Aug 2003 |
| 306 | Oklatex Energy, Inc. | Beaumont, TX 77702 | Oil Operator | Aug 2025 |
| 307 | Opex Energy, LLC | Houston, TX 77042 | Oil & Gas Operator | Mar 2008 |
| 308 | Opmi Operating Company | Houston, TX 77057 | Oil & Gas Operator | Jun 2008 |
| 309 | Oryx Energy Company | Dallas, TX 75221 | Oil & Gas Operator | May 2002 |
| 310 | Osborn,W.B. Oil & Gas Operations | San Antonio, TX 78217 | Oil & Gas Operator | Aug 2025 |
| 311 | Otex Resources LLC | Baytown, TX 77520 | Oil & Gas Operator | Aug 2025 |
| 312 | Outline Oil Corp. | San Antonio, TX 78217 | Oil & Gas Operator | Aug 2025 |
| 313 | Oxy USA Inc | Houston, TX 77046 | Oil & Gas Operator | Aug 2025 |
| 314 | P.O.&G. Operating, LLC | Houston, TX 77057 | Oil & Gas Operator | Aug 2025 |
| 315 | Palace Exploration Company | Houston, TX 77002 | Oil & Gas Operator | Mar 2007 |
| 316 | Parker & Parsley Development L.P | Midland, TX 79702 | Oil & Gas Operator | Oct 2007 |
| 317 | Patriot Operating Company, Inc. | Houston, TX 77008 | Oil & Gas Operator | Sep 2003 |
| 318 | Pax Petroleum Corporation | La Jolla, CA 92037 | Oil & Gas Operator | Mar 2008 |
| 319 | Peles, LLC | Houston, TX 77057 | Oil & Gas Operator | Aug 2025 |
| 320 | Pennzenergy Exp. & Prod., L.L.C. | Houston, TX 77210 | Oil & Gas Operator | Mar 2000 |
| 321 | Pennzoil Exploration & Production Co. | Carthage, TX 75633 | Oil & Gas Operator | Mar 2008 |
| 322 | Pennzoil Petroleum Company | Houston, TX 77252 | Oil & Gas Operator | Nov 1999 |
| 323 | Petro Resources, Inc. | Fulton, TX 78358 | Oil & Gas Operator | Aug 2025 |
| 324 | Petro Vest, Inc. | Houston, TX 77046 | Oil & Gas Operator | Sep 2014 |
| 325 | Petrodome Operating, LLC | Houston, TX 77265 | Oil & Gas Operator | Apr 2025 |
| 326 | Petrohawk Operating Company | Houston, TX 77056 | Oil & Gas Operator | Oct 2021 |
| 327 | Petropro Energy Partners, L.P. | Houston, TX 77024 | Oil & Gas Operator | Jan 2013 |
| 328 | Petrotx Operating, LLC | Kingwood, TX 77339 | Oil & Gas Operator | Aug 2025 |
| 329 | PH Exploration, Inc. | Houston, TX 77008 | Oil & Gas Operator | Nov 2001 |
| 330 | Phillips Petroleum Company | Houston, TX 77251 | Oil & Gas Operator | Mar 2013 |
| 331 | Phoenix Hydrocarbons Operating | Midland, TX 79702 | Oil & Gas Operator | Jun 2024 |
| 332 | Pi Energy, Inc. | Wichita Falls, TX 76301 | Oil & Gas Operator | Aug 2025 |
| 333 | Pierce Junction Petroleum Inc. | Houston, TX 77002 | Oil & Gas Operator | May 2010 |
| 334 | Plains Production Inc | Wichita Falls, TX 76308 | Oil & Gas Operator | Dec 1995 |
| 335 | Plantation Operating Co., Inc. | Holliday, TX 76366 | Oil & Gas Operator | Aug 2025 |
| 336 | Poco Oil Co. | Houston, TX 77069 | Oil & Gas Operator | Mar 1997 |
| 337 | Pride Energy Company | Tulsa, OK 74170 | Oil & Gas Operator | Aug 2025 |
| 338 | Primal Energy Corporation | The Woodlands, TX 77380 | Oil & Gas Operator | Aug 2025 |
| 339 | Prime Natural Resources, Inc. | Houston, TX 77042 | Oil & Gas Operator | Jun 2007 |
| 340 | Prime Operating Company | Houston, TX 77024 | Oil & Gas Operator | Aug 2025 |
| 341 | Primrose Resources, LLC | Cedar Park, TX 78630 | Oil & Gas Operator | Aug 2025 |
| 342 | Pringle Resources, Inc. | Houston, TX 77019 | Oil & Gas Operator | Aug 2025 |
| 343 | Proline Energy Resources Inc | Sugar Land, TX 77479 | Oil & Gas Operator | Aug 2025 |
| 344 | Puls Operating Company | Boerne, TX 78006 | Oil & Gas Operator | Aug 2025 |
| 345 | Puls, W. L. | Houston, TX 77084 | Oil & Gas Operator | Sep 2002 |
| 346 | PXP Gulf Coast Inc. | Houston, TX 77002 | Oil & Gas Operator | Mar 2015 |
| 347 | Quantum Resources Management LLC | Houston, TX 77010 | Oil & Gas Operator | May 2025 |
| 348 | Quintana Pet. Corp. | Refugio, TX 78377 | Oil & Gas Operator | Dec 2000 |
| 349 | R&R Resources Corporation | Houston, TX 77056 | Oil & Gas Operator | Dec 2015 |
| 350 | Radius Operating, LLC | Round Rock, TX 78664 | Oil & Gas Operator | Aug 2025 |
| 351 | Ramtex Energy LLC | Tulsa, OK 74114 | Oil & Gas Operator | Aug 2025 |
| 352 | Rana Energy Company | Spring, TX 77387 | Oil & Gas Operator | Mar 2008 |
| 353 | Range Production Company | Fort Worth, TX 76102 | Oil & Gas Operator | Sep 2021 |
| 354 | Rannic Inc. | Baytown, TX 77521 | Oil Operator | Aug 2025 |
| 355 | Rasmussen, Hal J. Operating, Inc | Midland, TX 79701 | Oil & Gas Operator | Apr 2009 |
| 356 | Redbird Oilfield Services Corp. | Splendora, TX 77372 | Oil & Gas Operator | Aug 2025 |
| 357 | Redstone Oil & Gas Company | Dallas, TX 75225 | Oil & Gas Operator | Jan 2020 |
| 358 | Reo Operating LLC | Austin, TX 78747 | Oil & Gas Operator | Aug 2025 |
| 359 | Resaca Resources, L.L.C. | Austin, TX 78746 | Oil & Gas Operator | Aug 2025 |
| 360 | Riley Exploration, LLC | Blanchard, OK 73010 | Oil & Gas Operator | Aug 2025 |
| 361 | Rio Bravo Oil Company | The Woodlands, TX 77381 | Oil & Gas Operator | Feb 2002 |
| 362 | Rio Energy | Houston, TX 77067 | Oil Operator | Aug 2025 |
| 363 | Rise Petroleum Investments LLC | Tomball, TX 77377 | Oil & Gas Operator | Aug 2025 |
| 364 | Riseden Services, Inc. | Houston, TX 77256 | Oil & Gas Operator | Sep 1997 |
| 365 | Rocinante | Houston, TX 77058 | Oil Operator | Aug 2025 |
| 366 | Rodeo Resources, L.L.C. | Houston, TX 77079 | Oil & Gas Operator | Dec 2024 |
| 367 | Rse, Inc. | Houston, TX 77077 | Oil & Gas Operator | Sep 2000 |
| 368 | RWJ Operating LLC | Dallas, TX 75201 | Oil & Gas Operator | Aug 2025 |
| 369 | Sabinal Resources, Inc. | Kingwood, TX 77339 | Oil & Gas Operator | Aug 2025 |
| 370 | Samson Exploration LLC | Tulsa, OK 74101 | Oil & Gas Operator | Jun 2025 |
| 371 | Samson Hydrocarbons Company | Tulsa, OK 74103 | Oil & Gas Operator | Nov 2016 |
| 372 | Samson Lone Star LP | Tulsa, OK 74103 | Oil & Gas Operator | Jun 2007 |
| 373 | Samson Lone Star, LLC | Tulsa, OK 74103 | Oil & Gas Operator | Aug 2025 |
| 374 | Samson Resources Company | Tulsa, OK 74103 | Oil & Gas Operator | May 2025 |
| 375 | Sanchez Oil & Gas Corporation | Houston, TX 77056 | Oil & Gas Operator | Aug 2025 |
| 376 | Sanchez-O'Brien Oil & Gas Corp | Houston, TX 77057 | Oil & Gas Operator | May 1998 |
| 377 | Sawtooth, Inc. | Houston, TX 77024 | Oil & Gas Operator | Dec 2013 |
| 378 | Saxet Exploration Ent. Co., Inc. | Fulshear, TX 77441 | Oil Operator | Aug 2025 |
| 379 | Scythian, LTD. | Midland, TX 79701 | Oil & Gas Operator | Dec 2020 |
| 380 | Seagull Energy E & P Inc | Houston, TX 77002 | Oil & Gas Operator | Jan 2015 |
| 381 | Seagull Mid-South Inc | Houston, TX 77002 | Oil & Gas Operator | Mar 2015 |
| 382 | Seashore Energy, Inc. | Boerne, TX 78006 | Oil & Gas Operator | Aug 2025 |
| 383 | Seco Petroleum Corp | Houston, TX 77290 | Oil & Gas Operator | Jan 1997 |
| 384 | Secondary Gas Recovery Inc. | Tulsa, OK 74119 | Oil & Gas Operator | Oct 1993 |
| 385 | Shelton, Charles M. | Baytown, TX 77521 | Oil & Gas Operator | Aug 2003 |
| 386 | Shidler, Mark L., Inc. | Houston, TX 77055 | Oil & Gas Operator | Aug 2025 |
| 387 | Shubuta Oil Corporation | Houston, TX 77056 | Oil & Gas Operator | Sep 1998 |
| 388 | Sideline Oil & Gas, L.P. | Friendswood, TX 77549 | Oil Operator | Aug 2025 |
| 389 | Siempre Energy Operating, LLC | Houston, TX 77094 | Oil Operator | Aug 2025 |
| 390 | Silver Pines Energy Corp. | Houston, TX 77005 | Oil & Gas Operator | May 2025 |
| 391 | Silverbrook Operating, LLC | Barker, TX 77413 | Oil Operator | Aug 2025 |
| 392 | Smith Energy 1986a Partnership | Alvin, TX 77511 | Oil & Gas Operator | Feb 2010 |
| 393 | Smith Oil Company | Smackover, AR 71762 | Oil Operator | Dec 2024 |
| 394 | Smith Petroleum Company | Spring, TX 77389 | Oil & Gas Operator | Aug 2025 |
| 395 | Smith Production Inc. | The Woodlands, TX 77381 | Oil & Gas Operator | Aug 2025 |
| 396 | Smith, L C Production | Jacksonville, TX 75766 | Oil Operator | Aug 2025 |
| 397 | Smith, L. C. | Jacksonville, TX 75766 | Oil & Gas Operator | Aug 2025 |
| 398 | Solano Gas Processing, Inc. | Austin, TX 78759 | Oil & Gas Operator | Aug 1998 |
| 399 | Sonora Petroleum Corp. | Austin, TX 78734 | Oil & Gas Operator | Aug 2025 |
| 400 | South Houston Production Company | Muenster, TX 76252 | Oil & Gas Operator | Aug 2025 |