| 301 | National Offshore LP | Oklahoma City, OK 73154 | Oil & Gas Operator | Mar 2008 |
| 302 | Nerco Oil & Gas Inc | | Oil & Gas Operator | Dec 1996 |
| 303 | Newfield Exploration Company | The Woodlands, TX 77380 | Oil & Gas Operator | Jun 2017 |
| 304 | Nippon Oil Exploration USA LTD | | Oil & Gas Operator | Dec 2010 |
| 305 | Noble Energy Inc | Midland, TX 79706 | Oil & Gas Operator | Feb 2026 |
| 306 | Noex, L.L.C. | Houston, TX 77057 | Oil & Gas Operator | Apr 1998 |
| 307 | North Central Oil Corp | Houston, TX 77252 | Oil & Gas Operator | Dec 2005 |
| 308 | Northcoast Oil Company | | Oil & Gas Operator | Mar 2009 |
| 309 | Ocean Energy Inc | Houston, TX 77002 | Oil & Gas Operator | Aug 2003 |
| 310 | Ody Oil Corp. | | Oil & Gas Operator | Oct 1994 |
| 311 | Offshore Shelf LLC | | Oil & Gas Operator | Dec 2007 |
| 312 | Oil And Gas Futures, Inc. | | Oil & Gas Operator | May 1977 |
| 313 | Orx Resources, Inc. | | Oil & Gas Operator | Dec 2009 |
| 314 | Orx Resources, L.L.C. | Houston, TX 77067 | Oil & Gas Operator | Feb 2026 |
| 315 | Oxtex Inc | | Oil & Gas Operator | Oct 1989 |
| 316 | P & P Producing Inc | Midland, TX 79702 | Oil & Gas Operator | Feb 2015 |
| 317 | Palace Operating Company | Tulsa, OK 74136 | Oil & Gas Operator | Aug 2009 |
| 318 | Paladin Petroleum III, L.L.C. | Austin, TX 78746 | Oil & Gas Operator | Feb 2026 |
| 319 | Palm Energy Offshore, L.L.C. | | Oil & Gas Operator | Apr 2019 |
| 320 | Pan Petroleum MLP | Kansas City, MO 64114 | Oil & Gas Operator | Aug 1997 |
| 321 | Pan-Ok Production Company | | Oil & Gas Operator | Nov 2024 |
| 322 | Panaco Production Co | Houston, TX 77002 | Oil & Gas Operator | Dec 1999 |
| 323 | Panaco, Inc. | Oklahoma City, OK 73102 | Oil & Gas Operator | Aug 2025 |
| 324 | Parker & Parsley Development Co. | Midland, TX 79702 | Oil & Gas Operator | May 1995 |
| 325 | Parker & Parsley Devpt L P | | Oil & Gas Operator | Oct 1997 |
| 326 | Partners Oil Company | Tulsa, OK 74135 | Oil & Gas Operator | Aug 1995 |
| 327 | Patrick Petroleum Corporation | | Oil & Gas Operator | Oct 1984 |
| 328 | Paxton Oil Company | | Oil & Gas Operator | Dec 2024 |
| 329 | Pel-Tex Oil Company, Inc. | | Oil & Gas Operator | Jul 1995 |
| 330 | Pelto Oil Company | Houston, TX 77002 | Oil & Gas Operator | Nov 1998 |
| 331 | Pend Oreille Oil & Gas Company | | Oil & Gas Operator | Sep 1989 |
| 332 | Pengo Petroleum Inc | | Oil & Gas Operator | Dec 2013 |
| 333 | Pengo Petroleum, Inc. & J.W.S. | | Oil & Gas Operator | Jul 1977 |
| 334 | Pengo Producing Company | | Oil & Gas Operator | Mar 1987 |
| 335 | Penn Exploration Corp. | | Gas Operator | Feb 1984 |
| 336 | Pennzenergy Explor & Prod LLC | | Oil & Gas Operator | Dec 1999 |
| 337 | Pennzoil Company | Midland, TX 79710-0090 | Oil & Gas Operator | Mar 2000 |
| 338 | Pennzoil E & P Co Et Al | | Oil & Gas Operator | Feb 1999 |
| 339 | Pennzoil E & P Co-Sohio Et Al | | Oil & Gas Operator | Jun 1991 |
| 340 | Pennzoil E & P Co-Sohio Petr | | Oil & Gas Operator | Feb 1999 |
| 341 | Pennzoil Exploration & Production Co. | Carthage, TX 75633 | Oil & Gas Operator | Mar 2008 |
| 342 | Pennzoil Petroleum Company | Houston, TX 77252 | Oil & Gas Operator | Nov 1999 |
| 343 | Perdido Energy Louisiana, LLC | | Oil & Gas Operator | Dec 2024 |
| 344 | Petro-Lewis Corp. | | Oil & Gas Operator | Feb 1994 |
| 345 | Petrodome Operating, LLC | Houston, TX 77265 | Oil & Gas Operator | May 2025 |
| 346 | Petrohawk Energy Corporation | Houston, TX 77002 | Oil & Gas Operator | Jun 2005 |
| 347 | Petrohawk Operating Company | Houston, TX 77056 | Oil & Gas Operator | Oct 2021 |
| 348 | Petroleum Corporation Of Texas | Breckenridge, TX 76024 | Oil & Gas Operator | May 2002 |
| 349 | Petroleum Resource MGMT Co TX | | Oil & Gas Operator | Sep 2020 |
| 350 | Petroquest Energy, L.L.C. | Lafayette, LA 70505 | Oil & Gas Operator | Feb 2026 |
| 351 | Petsec Energy Inc. | | Oil & Gas Operator | Sep 2012 |
| 352 | PG&E Resources Offshore Company | Dallas, TX 75206 | Oil & Gas Operator | Oct 1994 |
| 353 | Phillips Oil Company | Casper, WY 82602 | Oil & Gas Operator | Sep 1986 |
| 354 | Phillips Petroleum Company | Houston, TX 77251 | Oil & Gas Operator | Mar 2013 |
| 355 | Pinnacle Energy, LLC | | Oil & Gas Operator | Jan 2025 |
| 356 | Pioneer Natural Res. (GPC), Inc. | Midland, TX 79702 | Oil & Gas Operator | Apr 1998 |
| 357 | Pioneer Natural Resources USA Inc | Irving, TX 75039 | Oil & Gas Operator | Sep 2025 |
| 358 | Placid Oil Company | Houston, TX 77227 | Oil & Gas Operator | Mar 2008 |
| 359 | Pogo Producing Company | Houston, TX 77002 | Oil & Gas Operator | Jan 2008 |
| 360 | Poydras Energy Partners, LLC | | Oil & Gas Operator | Dec 2021 |
| 361 | Prairie Producing Company | | Oil & Gas Operator | Dec 1992 |
| 362 | Pride Energy Company | Tulsa, OK 74170 | Oil & Gas Operator | Feb 2026 |
| 363 | Prize Operating Company | Grapevine, TX 76051 | Oil & Gas Operator | Aug 2016 |
| 364 | Progress Petroleum Co. | | Oil & Gas Operator | Apr 1993 |
| 365 | PXP Gulf Coast Inc. | Houston, TX 77002 | Oil & Gas Operator | Mar 2015 |
| 366 | PXP Louisiana L.L.C. | | Oil & Gas Operator | Nov 2010 |
| 367 | Quintana Petroleum Corporation | Denver, CO 80265 | Oil & Gas Operator | Mar 1998 |
| 368 | Ramco Oil & Gas Inc | Midland, TX 79701 | Oil & Gas Operator | Nov 2006 |
| 369 | Ramco Operating Company | Tulsa, OK 74135 | Oil & Gas Operator | Jan 1998 |
| 370 | Rapiere Resources Company | | Oil & Gas Operator | Aug 2024 |
| 371 | Ray Estis | | Oil Operator | Dec 2024 |
| 372 | Red Willow Offshore, LLC | | Oil & Gas Operator | Apr 2011 |
| 373 | Reese Oil And Gas Company | | Oil & Gas Operator | Mar 1985 |
| 374 | Reita Oil Company | | Oil & Gas Operator | Jan 1987 |
| 375 | Renaissance Offshore, LLC | | Oil & Gas Operator | Mar 2023 |
| 376 | Research Enterprises, Inc. | | Oil Operator | Jan 1996 |
| 377 | Ridgelake Energy, Inc. | | Oil & Gas Operator | Jul 2020 |
| 378 | Riverwood Production Co., Inc. | | Oil & Gas Operator | Nov 1990 |
| 379 | Rme Petroleum Company | Houston, TX 77251 | Oil & Gas Operator | Nov 2016 |
| 380 | Robert W. Omeara | | Oil & Gas Operator | Sep 1988 |
| 381 | Roberts & Bunch Resources | | Oil & Gas Operator | Dec 1993 |
| 382 | Rockland Oil Company | Addison, TX 75001 | Oil & Gas Operator | Nov 2025 |
| 383 | Rosewood Resources (Poc), Inc. | | Oil & Gas Operator | Dec 1984 |
| 384 | Rosewood Resources Inc | Dallas, TX 75201 | Oil & Gas Operator | Feb 2026 |
| 385 | Roy M. Huffington, Inc. | | Oil & Gas Operator | Jul 1983 |
| 386 | Rozel Operating Company | | Oil & Gas Operator | Oct 2014 |
| 387 | S. Parish Oil Company, Inc. | | Oil & Gas Operator | Dec 1997 |
| 388 | S2 Energy 1, LP | | Oil & Gas Operator | Nov 2012 |
| 389 | S2 Energy Operating LLC | | Oil & Gas Operator | May 2023 |
| 390 | Saba Energy Of Texas Inc | Houston, TX 77042 | Oil & Gas Operator | Jul 2007 |
| 391 | Sabine Corporation | Oklahoma City, OK 73116 | Oil & Gas Operator | Jul 1996 |
| 392 | Samedan Oil Corporation | Houston, TX 77067 | Oil & Gas Operator | Dec 2019 |
| 393 | Samson Contour Energy E&P, LLC | Tulsa, OK 74103 | Oil & Gas Operator | Sep 2017 |
| 394 | Samson Hydrocarbons Company | Tulsa, OK 74103 | Oil & Gas Operator | Nov 2016 |
| 395 | Samson Resources Company | Tulsa, OK 74103 | Oil & Gas Operator | Nov 2025 |
| 396 | Santa Fe Braun Inc | Dallas, TX 75240-6620 | Oil & Gas Operator | Mar 1995 |
| 397 | Santa Fe Energy Operg Parts LP | | Oil & Gas Operator | Nov 1993 |
| 398 | Santa Fe Energy Resources, Inc. | Houston, TX 77024 | Oil & Gas Operator | Mar 2008 |
| 399 | Santa Fe Minerals, Inc. | Dallas, TX 75240 | Oil & Gas Operator | Sep 2013 |
| 400 | Santa Fe-Andover Oil Co | Tulsa, OK 74172 | Oil & Gas Operator | Sep 2000 |