| 301 | Patina Oil & Gas Corporation | Denver, CO 80202 | Oil & Gas Operator | May 2016 |
| 302 | Peak Operating Of Texas, LLC | Denver, CO 80202 | Oil & Gas Operator | May 2005 |
| 303 | Pegasus Energy | Oklahoma City, OK 73162 | Oil & Gas Operator | Apr 1997 |
| 304 | Pennzoil Exploration & Production Co. | Carthage, TX 75633 | Oil & Gas Operator | Mar 2008 |
| 305 | Pennzoil Petroleum Company | Houston, TX 77252 | Oil & Gas Operator | Nov 1999 |
| 306 | Petro-Haley | Borger, TX 79008 | Oil & Gas Operator | Oct 2025 |
| 307 | Petro-Hunt Corporation | Dallas, TX 75201 | Oil & Gas Operator | Jun 2003 |
| 308 | Petro-Hunt, L.L.C. | Dallas, TX 75201 | Oil & Gas Operator | Oct 2025 |
| 309 | Petrohawk Operating Company | Houston, TX 77056 | Oil & Gas Operator | Oct 2021 |
| 310 | Philcon Development Co. | Amarillo, TX 79101 | Oil & Gas Operator | Sep 2014 |
| 311 | Phillips Petroleum Company | Houston, TX 77251 | Oil & Gas Operator | Mar 2013 |
| 312 | Phoenix Operating Company Of TX. | Dallas, TX 75206 | Oil & Gas Operator | Jun 1995 |
| 313 | Pioneer Resources Producing, L.P | Irving, TX 75039 | Oil & Gas Operator | Feb 2001 |
| 314 | Plains Exploration & Prod. Co. | Houston, TX 77002 | Oil & Gas Operator | Jul 2013 |
| 315 | Plains Marketing, LP | Cushing, OK 74023 | Oil Operator | Jan 2012 |
| 316 | Plains Petroleum Operating Co. | Denver, CO 80202 | Oil & Gas Operator | Dec 2014 |
| 317 | Plantation Operating, LLC | Houston, TX 77041 | Oil & Gas Operator | Nov 2011 |
| 318 | PNG Gathering, LLC | Wellington, TX 79095 | Oil & Gas Operator | Dec 2024 |
| 319 | PNG Operating Company | Oklahoma City, OK 73172 | Oil & Gas Operator | Oct 2025 |
| 320 | PNG Production, LLC | Wellington, TX 79095 | Oil & Gas Operator | Oct 2025 |
| 321 | Pogo Panhandle 2004, L.P. | Houston, TX 77002 | Oil & Gas Operator | Oct 2017 |
| 322 | Pogo Producing Company | Houston, TX 77002 | Oil & Gas Operator | Jan 2008 |
| 323 | Pogo Producing Company LLC | Houston, TX 77002 | Oil & Gas Operator | Jul 2025 |
| 324 | Ponderosa TX Operating LLC | Stinnett, TX 79083 | Oil & Gas Operator | Oct 2025 |
| 325 | Pool, Lloyd Operating | Sandia Park, NM 87047 | Gas Operator | Dec 2013 |
| 326 | Prairie Energy Company | Fort Worth, TX 76185 | Oil & Gas Operator | Mar 2003 |
| 327 | Prairie Oil Company | Pampa, TX 79066 | Oil & Gas Operator | Jan 2017 |
| 328 | Premier Energy, Inc. | Shamrock, TX 79079 | Oil & Gas Operator | Mar 2008 |
| 329 | Presidio Petroleum LLC | Canadian, TX 79014 | Oil & Gas Operator | Oct 2025 |
| 330 | Prize Exploration & Prod, LLC | Oklahoma City, OK 73102 | Oil & Gas Operator | Oct 2025 |
| 331 | Prize Exploration, LLC | Oklahoma City, OK 73102 | Oil & Gas Operator | Oct 2025 |
| 332 | Production Gathering Company, LP | Dallas, TX 75206 | Oil & Gas Operator | Oct 2025 |
| 333 | Protege Energy LLC | Tulsa, OK 74135 | Oil & Gas Operator | Jan 2018 |
| 334 | PXP Gulf Coast Inc. | Houston, TX 77002 | Oil & Gas Operator | Mar 2015 |
| 335 | Pyramid Energy Inc | San Antonio, TX 78216 | Oil & Gas Operator | Feb 2012 |
| 336 | Qep Energy Company | Midland, TX 79701 | Oil & Gas Operator | Jun 2025 |
| 337 | Quantum Resources Management LLC | Houston, TX 77010 | Oil & Gas Operator | Jun 2025 |
| 338 | Quarles Drilling Corporation | Tulsa, OK 74136 | Oil & Gas Operator | Feb 2008 |
| 339 | Questa Energy Corporation | Amarillo, TX 79159 | Oil & Gas Operator | Oct 2025 |
| 340 | Questa Operating Company, LLC | Amarillo, TX 79159 | Oil & Gas Operator | Oct 2025 |
| 341 | Questar Expl. And Prod. Co. | Salt Lake Cty, UT 84145 | Oil & Gas Operator | Jul 2011 |
| 342 | R.E.D. Resources, Inc. | Perryton, TX 79070 | Oil & Gas Operator | Apr 2004 |
| 343 | Ramco Operating Company | Tulsa, OK 74135 | Oil & Gas Operator | Jan 1998 |
| 344 | Ramsey & Gassaway | Borger, TX 79008 | Gas Operator | Jun 1999 |
| 345 | Raydon Exploration, Inc. | Oklahoma City, OK 73118 | Oil & Gas Operator | Oct 2025 |
| 346 | Reneau Oil Co. | Shamrock, TX 79079 | Oil & Gas Operator | Oct 2025 |
| 347 | Reneau, James R. | Shamrock, TX 79079 | Gas Operator | Oct 2001 |
| 348 | Reneau, James Seed Co. | Shamrock, TX 79079 | Oil & Gas Operator | Oct 2025 |
| 349 | Residual Flow Operating, LLC | | Oil Operator | Oct 2025 |
| 350 | Resource Oil And Gas, LLC | Oklahoma City, OK 73114 | Oil & Gas Operator | Oct 2025 |
| 351 | Revelation Oil & Gas LLC | Dumas, TX 79029 | Oil & Gas Operator | Oct 2025 |
| 352 | Rhyne, J.V. | Cisco, TX 76437 | Oil & Gas Operator | Oct 2025 |
| 353 | Richland Resources Corporation | Oklahoma City, OK 73114 | Oil & Gas Operator | Oct 2025 |
| 354 | Ricon Petroleum Company | Shamrock, TX 79079 | Oil & Gas Operator | Mar 2008 |
| 355 | Rimrock Gas Company | Weatherford, OK 73096 | Oil & Gas Operator | May 2008 |
| 356 | Rio Grande Drilling Company | San Antonio, TX 78212 | Oil & Gas Operator | Dec 1999 |
| 357 | Rio Petroleum, Inc. | Amarillo, TX 79102 | Oil & Gas Operator | Oct 2025 |
| 358 | Rki Energy Resources, LLC | Oklahoma City, OK 73102 | Oil & Gas Operator | Jun 2021 |
| 359 | Rki Exploration & Production LLC | Tulsa, OK 74172 | Oil & Gas Operator | Oct 2025 |
| 360 | Romines & Warner | Pampa, TX 79065 | Oil & Gas Operator | Jan 2002 |
| 361 | Romines Operating Group | Pampa, TX 79066 | Oil & Gas Operator | Nov 2022 |
| 362 | Rosewood Resources, Inc. | Dallas, TX 75201 | Oil & Gas Operator | Oct 2025 |
| 363 | Rover Petroleum Operating, LLC | Fort Worth, TX 76101 | Oil & Gas Operator | Oct 2025 |
| 364 | Roy Production Co. | Shamrock, TX 79079 | Oil & Gas Operator | Jul 2012 |
| 365 | Royal Oil & Gas Corp. | Indiana, PA 15701 | Oil & Gas Operator | Apr 2014 |
| 366 | S & J Operating Company | Wichita Falls, TX 76301 | Oil & Gas Operator | Mar 2015 |
| 367 | Samedan Oil Corporation | Houston, TX 77067 | Oil & Gas Operator | Dec 2019 |
| 368 | Samis Oil Company, Inc. | Oklahoma City, OK 73156 | Oil & Gas Operator | Sep 2000 |
| 369 | Samson Hydrocarbons Company | Tulsa, OK 74103 | Oil & Gas Operator | Nov 2016 |
| 370 | Samson Lone Star LP | Tulsa, OK 74103 | Oil & Gas Operator | Jun 2007 |
| 371 | Samson Lone Star, LLC | Tulsa, OK 74103 | Oil & Gas Operator | Oct 2025 |
| 372 | Samson Resources Company | Tulsa, OK 74103 | Oil & Gas Operator | Jun 2025 |
| 373 | Sanders & Smith, L.C. | Amarillo, TX 79110 | Oil & Gas Operator | Mar 2004 |
| 374 | Sandlot Oil & Gas LLC | Gruver, TX 79040 | Oil & Gas Operator | Oct 2025 |
| 375 | Sanguine Gas Exploration, LLC | Tulsa, OK 74119 | Oil & Gas Operator | Oct 2025 |
| 376 | Santa Fe Energy Oper. Part., LP | Houston, TX 77057 | Oil & Gas Operator | Dec 1994 |
| 377 | Saxet Operating Co.,Inc. | Madisonville, TX 77864 | Oil & Gas Operator | Oct 2025 |
| 378 | Sbog, LLC | Granbury, TX 76048 | Oil & Gas Operator | Feb 2021 |
| 379 | Scout Energy Management LLC | Dallas, TX 75240 | Oil & Gas Operator | Oct 2025 |
| 380 | Seagull Energy E & P Inc | Houston, TX 77002 | Oil & Gas Operator | Jan 2015 |
| 381 | Seagull Midcon Inc. | Houston, TX 77002 | Oil & Gas Operator | Mar 2015 |
| 382 | Shamrock Texas Partners L.P. | San Angelo, TX 76904 | Oil & Gas Operator | Oct 2025 |
| 383 | Shannon Energy | Liberal, KS 67901 | Oil & Gas Operator | Feb 1999 |
| 384 | Sheridan Energy,Inc. | Houston, TX 77002 | Oil & Gas Operator | Feb 2000 |
| 385 | Sidwell Oil & Gas, Inc. | Amarillo, TX 79105 | Oil & Gas Operator | Sep 2014 |
| 386 | Sidwell Operating Company, L.P. | Amarillo, TX 79105 | Oil & Gas Operator | Oct 2025 |
| 387 | Sierra Group, L.L.C. | San Angelo, TX 76904 | Oil & Gas Operator | Jan 2025 |
| 388 | Sierra Resources, Inc. | Oklahoma City, OK 73142 | Oil & Gas Operator | Aug 2025 |
| 389 | Sigma Exploration Corp., The | Dallas, TX 75230 | Oil & Gas Operator | Sep 1998 |
| 390 | Skycap Energy, LLC | Oklahoma City, OK 73118 | Oil & Gas Operator | Jul 2025 |
| 391 | SLT Dakota Operating, Inc. | Yukon, OK 73099 | Oil & Gas Operator | Oct 2025 |
| 392 | SM Energy Company | Midland, TX 79707 | Oil & Gas Operator | Oct 2025 |
| 393 | SMR Natural Gas Ventures Inc | Oklahoma City, OK 73112 | Oil & Gas Operator | Jan 1999 |
| 394 | Snappy Services, Inc. | Pampa, TX 79066 | Oil & Gas Operator | Oct 2025 |
| 395 | Sonat Exploration Co. | Houston, TX 77251 | Oil & Gas Operator | Dec 2021 |
| 396 | Sonat Exploration Company-MCR | Houston, TX 77251 | Oil & Gas Operator | Dec 1999 |
| 397 | Spindletop Drilling Co. | Dallas, TX 75230 | Oil & Gas Operator | Oct 2025 |
| 398 | Spindletop Oil & Gas Co. | Dallas, TX 75230 | Oil & Gas Operator | Oct 2025 |
| 399 | St. Mary Energy Company | Houston, TX 77079 | Oil & Gas Operator | Aug 2008 |
| 400 | St. Mary Land & Exploration Co | Denver, CO 80201 | Oil & Gas Operator | Jun 2010 |