| 301 | Orx Resources, L.L.C. | Houston, TX 77067 | Oil & Gas Operator | Mar 2026 |
| 302 | Oryx Energy Company | Dallas, TX 75221 | Oil & Gas Operator | May 2002 |
| 303 | Oso Exploration Co. | San Antonio, TX 78217 | Oil & Gas Operator | Jul 2011 |
| 304 | Outline Oil Company LLC | Beeville, TX 78104 | Oil Operator | Mar 2026 |
| 305 | Pace Oil And Gas Company | Austin, TX 78715 | Oil & Gas Operator | Mar 2026 |
| 306 | Pace Production Co. | San Angelo, TX 76902 | Oil & Gas Operator | Mar 2026 |
| 307 | Paisano Petroleum, Inc. | San Antonio, TX 78246 | Oil & Gas Operator | Dec 2016 |
| 308 | Paladin Petroleum III, L.L.C. | Austin, TX 78746 | Oil & Gas Operator | Mar 2026 |
| 309 | Paleo Oil Company LLC | Corpus Chrsti, TX 78411 | Oil & Gas Operator | Mar 2026 |
| 310 | Paloma Operating, LLC | Corpus Chrsti, TX 78401 | Oil & Gas Operator | Mar 2026 |
| 311 | Parker & Parsley Development L.P | Midland, TX 79702 | Oil & Gas Operator | Oct 2007 |
| 312 | Parker & Parsley Producing LP | Midland, TX 79702 | Oil & Gas Operator | Oct 1997 |
| 313 | Parker, Robert Production, Inc. | Alice, TX 78333 | Gas Operator | Nov 1996 |
| 314 | Pearl, Bill H. Productions, Inc. | Corpus Chrsti, TX 78460 | Oil & Gas Operator | Mar 2026 |
| 315 | Pentad Development Corp. (A) | Dallas, TX 75201 | Oil & Gas Operator | Mar 1993 |
| 316 | Perez, H. F. | Alice, TX 78332 | Oil & Gas Operator | May 2023 |
| 317 | Petrogen, Incorporated | Katy, TX 77450 | Oil & Gas Operator | Jan 2012 |
| 318 | Petrohawk Operating Company | Houston, TX 77056 | Oil & Gas Operator | Oct 2021 |
| 319 | Petroleum Management, Inc. | Corpus Chrsti, TX 78471 | Oil & Gas Operator | Mar 2026 |
| 320 | Petroleum Recovery Systems, L.C. | Houston, TX 77024 | Oil Operator | Mar 2026 |
| 321 | Pine Island Production Company | Corpus Chrsti, TX 78403 | Oil & Gas Operator | Apr 2012 |
| 322 | Pintex Operating Inc. | Corpus Chrsti, TX 78478 | Oil & Gas Operator | Feb 2005 |
| 323 | Placer Oil Co. | Sugar Land, TX 77479 | Oil & Gas Operator | Apr 2008 |
| 324 | Platform Operating, LLC | Midland, TX 79702 | Oil & Gas Operator | Mar 2026 |
| 325 | Pmi Energy Co. | Corpus Chrsti, TX 78471 | Oil & Gas Operator | Aug 2002 |
| 326 | Poco LLC | Houston, TX 77270 | Oil & Gas Operator | Mar 2026 |
| 327 | Premier Minerals, Inc. | San Antonio, TX 78209 | Oil & Gas Operator | Mar 2026 |
| 328 | Prevail Energy, Inc | Corpus Chrsti, TX 78469 | Oil & Gas Operator | Mar 2026 |
| 329 | Progas Operating, Inc | Red Rock, TX 78662 | Oil & Gas Operator | Mar 2026 |
| 330 | Progas Properties, Inc. | New Braunfels, TX 78132 | Oil & Gas Operator | Mar 2026 |
| 331 | Proline Energy Resources Inc | Sugar Land, TX 77479 | Oil & Gas Operator | Mar 2026 |
| 332 | Property Development Group, Inc. | San Antonio, TX 78212 | Oil & Gas Operator | Mar 2026 |
| 333 | Proton Energy, L.L.C. | Houston, TX 77002 | Oil & Gas Operator | Jun 2005 |
| 334 | Pyramid Energy Inc | San Antonio, TX 78216 | Oil & Gas Operator | Feb 2012 |
| 335 | Quatro Oil And Gas, Inc. | Joshua, TX 76058 | Oil & Gas Operator | Mar 2026 |
| 336 | Quintana Pet. Corp. | Refugio, TX 78377 | Oil & Gas Operator | Dec 2000 |
| 337 | R.C.I. Energy | Alice, TX 78333 | Oil & Gas Operator | Mar 2026 |
| 338 | Ragars Oil & Gas Co. | Austin, TX 78746 | Oil & Gas Operator | Mar 2026 |
| 339 | Reddy Disposals, LLC | Beeville, TX 78104 | Oil Operator | Mar 2026 |
| 340 | Redman Operating Company | Houston, TX 77042 | Oil & Gas Operator | May 2008 |
| 341 | Regal Operating | Cisco, TX 76437 | Oil & Gas Operator | Mar 2008 |
| 342 | Reh Energy, Inc. | Corpus Chrsti, TX 78413 | Oil & Gas Operator | Mar 2026 |
| 343 | Remora Operating LLC | Houston, TX 77056 | Oil & Gas Operator | Mar 2026 |
| 344 | Republic Resources, LLC. | San Antonio, TX 78212 | Oil & Gas Operator | Mar 2026 |
| 345 | Reserve Operating Corp. | Houston, TX 77040 | Oil & Gas Operator | Mar 2026 |
| 346 | Ricks Exploration, Inc. | Oklahoma City, OK 73154 | Oil & Gas Operator | Mar 2008 |
| 347 | Riddle Engineering Corp. | Corpus Chrsti, TX 78401 | Oil & Gas Operator | Jul 2011 |
| 348 | Rincon Petroleum Corporation | Corpus Chrsti, TX 78427 | Oil & Gas Operator | Mar 2026 |
| 349 | Rio Bravo Expl. & Prod. Co. | Houston, TX 77055 | Oil & Gas Operator | Apr 2020 |
| 350 | Rio Grande Drilling Company | San Antonio, TX 78212 | Oil & Gas Operator | Dec 1999 |
| 351 | Rising Star Energy, L.L.C. | Dallas, TX 75219 | Oil & Gas Operator | Aug 2006 |
| 352 | Rme Petroleum Company | Houston, TX 77251 | Oil & Gas Operator | Nov 2016 |
| 353 | Robison, J. H. & Assoc. LTD. | Corpus Chrsti, TX 78413 | Oil & Gas Operator | Apr 1996 |
| 354 | Rock Resources, Inc. | Corpus Chrsti, TX 78414 | Oil & Gas Operator | Mar 2026 |
| 355 | Rockwell Energy, LLC | Spring, TX 77386 | Oil & Gas Operator | Sep 2014 |
| 356 | Rodessa Operating Company | Corpus Chrsti, TX 78426 | Oil & Gas Operator | Mar 2026 |
| 357 | Rollert Co., Inc., The | Luling, TX 78648 | Oil & Gas Operator | Nov 2000 |
| 358 | Roma Oil And Gas, Inc. | San Antonio, TX 78209 | Oil & Gas Operator | Mar 2026 |
| 359 | Royal Texas Petroleum | Lago VIsta, TX 78645 | Oil & Gas Operator | Mar 2026 |
| 360 | Royko Oil Company | Horseshoe Bay, TX 78657 | Oil & Gas Operator | Mar 2026 |
| 361 | Ruwco Oil And Gas Corp. | Austin, TX 78701 | Oil & Gas Operator | Aug 2021 |
| 362 | RWJ Operating LLC | Dallas, TX 75201 | Oil & Gas Operator | Mar 2026 |
| 363 | Samedan Oil Corporation | Houston, TX 77067 | Oil & Gas Operator | Dec 2019 |
| 364 | Samson Hydrocarbons Company | Tulsa, OK 74103 | Oil & Gas Operator | Nov 2016 |
| 365 | Samson Lone Star LP | Tulsa, OK 74103 | Oil & Gas Operator | Jun 2007 |
| 366 | Samson Resources Company | Tulsa, OK 74103 | Oil & Gas Operator | Dec 2025 |
| 367 | San Isidro Development Co, L. C. | Sandia, TX 78383 | Oil & Gas Operator | Mar 2026 |
| 368 | Sanchez-O'Brien Oil & Gas Corp | Houston, TX 77057 | Oil & Gas Operator | May 1998 |
| 369 | Sandalwood Exploration, L.P. | Houston, TX 77056 | Oil & Gas Operator | Mar 2026 |
| 370 | Sandalwood Oil & Gas, Inc. | Houston, TX 77057 | Oil & Gas Operator | Mar 2026 |
| 371 | Sandia Energy Corporation-NM | Holdenville, OK 74848 | Oil & Gas Operator | Aug 2003 |
| 372 | Sarita Energy Resources, LTD. | Houston, TX 77277 | Oil & Gas Operator | Mar 2026 |
| 373 | Savage Exploration, Inc. | San Marcos, TX 78666 | Oil & Gas Operator | Mar 2026 |
| 374 | Saxet Petroleum, Inc. | Houston, TX 77057 | Oil & Gas Operator | Mar 2026 |
| 375 | Scana Petroleum Resources Inc | Houston, TX 77002 | Oil & Gas Operator | Jun 2013 |
| 376 | Setex Oil And Gas Company | Houston, TX 77002 | Oil & Gas Operator | Feb 2012 |
| 377 | Setex Oil Company, L.P. | Houston, TX 77060 | Oil & Gas Operator | Jan 2000 |
| 378 | Shoreham Oil & Gas Company, Inc. | Katy, TX 77492 | Oil & Gas Operator | Mar 2026 |
| 379 | Sien Operating Company, LLC | San Antonio, TX 78209 | Oil Operator | May 2023 |
| 380 | Sierra Exploration Company | San Antonio, TX 78209 | Oil & Gas Operator | Mar 2008 |
| 381 | Slawson Exploration Company Inc | Oklahoma City, OK 73102 | Oil & Gas Operator | Mar 2026 |
| 382 | Smith Petroleum Company | Spring, TX 77389 | Oil & Gas Operator | Mar 2026 |
| 383 | Sonterra Oil & Gas, Inc. | Wichita, KS 67217 | Oil & Gas Operator | Mar 2026 |
| 384 | Southern Royalty Inc. | Corpus Chrsti, TX 78411 | Oil & Gas Operator | Feb 1997 |
| 385 | Southwest Oil & Land, Inc. | Corpus Chrsti, TX 78460 | Oil & Gas Operator | Dec 1999 |
| 386 | Spartan Operating Company, Inc. | Tyler, TX 75702 | Oil & Gas Operator | Feb 2013 |
| 387 | Stacha, Eddy A. | Rice, TX 75155 | Oil & Gas Operator | Mar 2026 |
| 388 | Stallion Oil Company | Lafayette, LA 70505 | Oil & Gas Operator | Jun 2004 |
| 389 | Star Oil & Gas | Ben Bolt, TX 78342 | Oil & Gas Operator | Mar 2026 |
| 390 | Star Production, Inc. | Dallas, TX 75360 | Oil & Gas Operator | Mar 2026 |
| 391 | Starr Operating, LLC | San Antonio, TX 78209 | Oil & Gas Operator | Mar 2026 |
| 392 | Startex Energy, Inc. | Abilene, TX 79608 | Oil & Gas Operator | Mar 2026 |
| 393 | Sterling Engine Service, Inc. | Alice, TX 78333 | Oil & Gas Operator | Mar 2026 |
| 394 | Sue-Ann Operating, L.C. | Victoria, TX 77903 | Oil & Gas Operator | Mar 2026 |
| 395 | Sue-Ann Production Company | Victoria, TX 77903 | Oil & Gas Operator | Mar 2008 |
| 396 | Suemaur Exploration, Inc. | Corpus Chrsti, TX 78470 | Oil & Gas Operator | Mar 2008 |
| 397 | Sun Exploration, Inc. | Alice, TX 78333 | Oil & Gas Operator | Mar 2026 |
| 398 | SV Energy Company, LLC | Corpus Chrsti, TX 78401 | Oil & Gas Operator | Mar 2017 |
| 399 | Swift Energy Company | Houston, TX 77060 | Oil & Gas Operator | Mar 2021 |
| 400 | Swope Corp. | Austin, TX 78735 | Oil & Gas Operator | Mar 2026 |