| 301 | Petrotex Engineering Company | Cypress, TX 77429 | Oil & Gas Operator | Apr 2024 |
| 302 | Phillips Petroleum Company | Houston, TX 77251 | Oil & Gas Operator | Mar 2013 |
| 303 | Phoenix Hydrocarbons Operating | Midland, TX 79702 | Oil & Gas Operator | Apr 2024 |
| 304 | Phylko Energy Corporation | Houston, TX 77056 | Oil & Gas Operator | Aug 2003 |
| 305 | Pioneer Resources Producing, L.P | Irving, TX 75039 | Oil & Gas Operator | Feb 2001 |
| 306 | Placid Oil Company | Houston, TX 77227 | Oil & Gas Operator | Mar 2008 |
| 307 | Plains Marketing LP | Cushing, OK 74023 | Oil & Gas Operator | Dec 2022 |
| 308 | Plains Resources Inc. | Houston, TX 77002 | Oil & Gas Operator | Jul 2008 |
| 309 | Polaris Enterprises Inc | Houston, TX 77057 | Oil & Gas Operator | Oct 1998 |
| 310 | Poynor Corporation | Beaumont, TX 77706 | Oil & Gas Operator | Apr 2024 |
| 311 | Prime Operating Company | Houston, TX 77024 | Oil & Gas Operator | Apr 2024 |
| 312 | Proline Energy Resources Inc | Sugar Land, TX 77479 | Oil & Gas Operator | Apr 2024 |
| 313 | Prolithic Energy Company, L.P. | Corpus Chrsti, TX 78401 | Oil & Gas Operator | Aug 2002 |
| 314 | Puls Operating Company | Boerne, TX 78006 | Oil & Gas Operator | Apr 2024 |
| 315 | Puls, W. L. | Houston, TX 77084 | Oil & Gas Operator | Sep 2002 |
| 316 | Pyramid Exploration | Houston, TX 77241 | Oil & Gas Operator | Sep 1995 |
| 317 | Range Production Company | Fort Worth, TX 76102 | Oil & Gas Operator | Sep 2021 |
| 318 | Ranger Oil Company | Canada, 00100 | Oil & Gas Operator | Sep 2001 |
| 319 | Reb Petroleum Company | Sugar Land, TX 77478 | Oil & Gas Operator | Apr 2024 |
| 320 | Red Wolf Oil Company, Inc. | Brenham, TX 77833 | Oil & Gas Operator | Apr 2024 |
| 321 | Regal Petroleum Services | Euless, TX 76039 | Oil & Gas Operator | Aug 2002 |
| 322 | Republic Resources, LLC. | San Antonio, TX 78212 | Oil & Gas Operator | Apr 2024 |
| 323 | Rim Operating, Inc. | Englewood, CO 80112 | Oil & Gas Operator | Apr 2024 |
| 324 | Rio Bravo Oil Company | The Woodlands, TX 77381 | Oil & Gas Operator | Feb 2002 |
| 325 | Rockwall Marketing Corporation | Benbrook, TX 76126 | Oil & Gas Operator | Dec 2007 |
| 326 | Rosetta Resources Operating LP | San Antonio, TX 78216 | Oil & Gas Operator | Apr 2024 |
| 327 | Rotation, Incorporated | Houston, TX 77057 | Oil & Gas Operator | Mar 2023 |
| 328 | Royal Oil & Gas Corp. | Indiana, PA 15701 | Oil & Gas Operator | Apr 2014 |
| 329 | Royal Production Company, Inc. | Corpus Chrsti, TX 78401 | Oil & Gas Operator | Apr 2024 |
| 330 | Rutherford Oil Corporation | Houston, TX 77046 | Oil & Gas Operator | Jun 2019 |
| 331 | S & S Energy | Englewood, CO 80112 | Oil & Gas Operator | Mar 2015 |
| 332 | S & S Operating Company, Inc. | Winnie, TX 77665 | Oil & Gas Operator | Apr 2024 |
| 333 | Safari Production Company, Inc. | McAllen, TX 78501 | Oil & Gas Operator | Apr 2024 |
| 334 | Samedan Oil Corporation | Houston, TX 77067 | Oil & Gas Operator | Dec 2019 |
| 335 | Samson Exploration LLC | Tulsa, OK 74101 | Oil & Gas Operator | Feb 2024 |
| 336 | Samson Hydrocarbons Company | Tulsa, OK 74103 | Oil & Gas Operator | Nov 2016 |
| 337 | Samson Lone Star LP | Tulsa, OK 74103 | Oil & Gas Operator | Jun 2007 |
| 338 | Samson Lone Star, LLC | Tulsa, OK 74103 | Oil & Gas Operator | Apr 2024 |
| 339 | Samson Resources Company | Tulsa, OK 74103 | Oil & Gas Operator | Feb 2024 |
| 340 | Sanchez Oil & Gas Corporation | Houston, TX 77056 | Oil & Gas Operator | Apr 2024 |
| 341 | Sanchez-O'Brien Oil & Gas Corp | Houston, TX 77057 | Oil & Gas Operator | May 1998 |
| 342 | Sand Hawk, LLC | Devers, TX 77538 | Oil & Gas Operator | Apr 2024 |
| 343 | Sandel Operating Company | Huntsville, TX 77340 | Oil & Gas Operator | Apr 2024 |
| 344 | Sandpoint Texas LLC | Houston, TX 77270 | Oil Operator | Apr 2024 |
| 345 | Sandridge Offshore, LLC | Houston, TX 77042 | Oil & Gas Operator | Apr 2014 |
| 346 | Sandridge Onshore, LLC | Houston, TX 77010 | Oil & Gas Operator | Jun 2014 |
| 347 | Santa Fe Energy Oper. Part., LP | Houston, TX 77057 | Oil & Gas Operator | Dec 1994 |
| 348 | Sawtooth Operating Co., Inc. | Houston, TX 77024 | Oil & Gas Operator | Apr 2024 |
| 349 | Scana Exploration Company | Houston, TX 77002 | Oil & Gas Operator | Dec 1999 |
| 350 | Scana Petroleum Resources Inc | Houston, TX 77002 | Oil & Gas Operator | Jun 2013 |
| 351 | Scana Production Company | Houston, TX 77002 | Oil & Gas Operator | Mar 2005 |
| 352 | Seabreeze Production Co | Hungerford, TX 77448 | Oil & Gas Operator | Apr 2024 |
| 353 | Secondary Gas Recovery Inc. | Tulsa, OK 74119 | Oil & Gas Operator | Oct 1993 |
| 354 | Shale Oil Co., Inc. | Liberty, TX 77575 | Oil & Gas Operator | Apr 2024 |
| 355 | Sheridan Energy,Inc. | Houston, TX 77002 | Oil & Gas Operator | Feb 2000 |
| 356 | Shidler, Mark L., Inc. | Houston, TX 77055 | Oil & Gas Operator | Apr 2024 |
| 357 | Shoco Production LLC | Kilgore, TX 75663 | Oil & Gas Operator | Apr 2024 |
| 358 | Shoco Production, L.P. | Kilgore, TX 75663 | Oil & Gas Operator | May 2020 |
| 359 | Shoreham Oil & Gas Company, Inc. | Katy, TX 77492 | Oil & Gas Operator | Apr 2024 |
| 360 | Smith Oil Company | Smackover, AR 71762 | Oil Operator | Mar 2024 |
| 361 | Smith Production Inc. | The Woodlands, TX 77381 | Oil & Gas Operator | Apr 2024 |
| 362 | Solatex Resources, LTD | Houston, TX 77257 | Oil & Gas Operator | Apr 2024 |
| 363 | Southern G Holdings, LLC | Houston, TX 77002 | Oil & Gas Operator | Dec 2007 |
| 364 | Southland Royalty Company | Houston, TX 77210 | Oil & Gas Operator | Sep 2011 |
| 365 | Southwestern Energy Prod Co | Houston, TX 77032 | Oil & Gas Operator | Jun 2015 |
| 366 | Spindletop Drilling Co. | Dallas, TX 75230 | Oil & Gas Operator | Apr 2024 |
| 367 | Square Mile Energy, L.L.C. | Houston, TX 77057 | Oil & Gas Operator | Apr 2024 |
| 368 | St. Mary Energy Company | Houston, TX 77079 | Oil & Gas Operator | Aug 2008 |
| 369 | Stratco Operating Co Inc | Austin, TX 78701 | Oil & Gas Operator | Apr 2024 |
| 370 | Sue-Ann Production Company | Victoria, TX 77903 | Oil & Gas Operator | Mar 2008 |
| 371 | Suemaur Expl. & Prod., LLC | Corpus Chrsti, TX 78401 | Oil & Gas Operator | Apr 2024 |
| 372 | Suemaur Exploration, Inc. | Corpus Chrsti, TX 78470 | Oil & Gas Operator | Mar 2008 |
| 373 | Summit Resources, Inc. | Houston, TX 77077 | Oil & Gas Operator | Sep 2016 |
| 374 | Sure Flow Oil & Gas Company | Victoria, TX 77902 | Oil & Gas Operator | Mar 2008 |
| 375 | Sure Flow Oil & Gas, Inc. | Victoria, TX 77902 | Oil & Gas Operator | Apr 2024 |
| 376 | Swift Energy Company | Houston, TX 77060 | Oil & Gas Operator | Mar 2021 |
| 377 | Tandem Energy Corporation | Houston, TX 77056 | Oil & Gas Operator | Apr 2024 |
| 378 | Tema Oil And Gas Company | Houston, TX 77084 | Oil & Gas Operator | Apr 2024 |
| 379 | Tempest Energy Resources, LP | Houston, TX 77251 | Oil & Gas Operator | Jun 2013 |
| 380 | Tepee Petroleum Company, Inc. | Houston, TX 77098 | Oil & Gas Operator | Feb 2014 |
| 381 | Texaco E & P Inc | Houston, TX 77099 | Oil & Gas Operator | Apr 2024 |
| 382 | Texas Crude, Inc. | Houston, TX 77256 | Oil & Gas Operator | Oct 1995 |
| 383 | Texas Fuel Company | Galveston, TX 77550 | Oil & Gas Operator | Apr 2024 |
| 384 | Texas Petroleum Investment Company | Houston, TX 77057 | Oil & Gas Operator | Apr 2024 |
| 385 | Texas, Les & Co. | Austin, TX 78746 | Oil & Gas Operator | Apr 2024 |
| 386 | Texcal Energy (GP) LLC | Denver, CO 80202 | Oil & Gas Operator | Mar 2016 |
| 387 | Texcal Oil Inc. | Vidor, TX 77662 | Oil & Gas Operator | Jun 1999 |
| 388 | Texstar North America, Inc. | Waynesboro, MS 39367 | Oil & Gas Operator | Aug 1994 |
| 389 | Titan Rock E&P, LLC | Kilgore, TX 75663 | Oil & Gas Operator | Jan 2024 |
| 390 | Tomlinson, Thomas K. Inc. | Port Lavaca, TX 77979 | Oil & Gas Operator | Jul 2003 |
| 391 | Torch Operating Company | Houston, TX 77010 | Oil & Gas Operator | Mar 2015 |
| 392 | Torrent Oil LLC | Houston, TX 77002 | Oil & Gas Operator | Apr 2024 |
| 393 | Tpet Management Inc. | Dallas, TX 75204 | Oil & Gas Operator | Dec 1997 |
| 394 | Trans-Pecos Resources, Inc. | Houston, TX 77056 | Oil & Gas Operator | Apr 2024 |
| 395 | Transamerican Natural Gas Corp. | Houston, TX 77032 | Oil & Gas Operator | Aug 2000 |
| 396 | Transtexas Gas Corporation | Houston, TX 77265 | Oil & Gas Operator | Aug 2005 |
| 397 | Tri-Union Development Corp. | Houston, TX 77002 | Oil & Gas Operator | Apr 2024 |
| 398 | Trinity Resources, Inc. | Houston, TX 77277 | Oil & Gas Operator | May 2020 |
| 399 | Trinity River Operating Company | Oklahoma City, OK 73147 | Oil & Gas Operator | Apr 2024 |
| 400 | True Oil Company | Casper, WY 82602 | Oil & Gas Operator | Aug 2003 |