| 301 | Primos Oil & Gas Corp. | | Gas Operator | Dec 2001 |
| 302 | Primos Production | | Oil & Gas Operator | Dec 2024 |
| 303 | Primos-Pennzoil JV | | Gas Operator | Feb 2005 |
| 304 | Pritchard Engineering | | Oil & Gas Operator | Mar 1989 |
| 305 | Prize Operating Company | Grapevine, TX 76051 | Oil & Gas Operator | Aug 2016 |
| 306 | Probe Offshore, LLC | Houston, TX 77002 | Oil & Gas Operator | Feb 2009 |
| 307 | Procell & Procell | | Oil & Gas Operator | Jan 2003 |
| 308 | Producers Gas Transmission Inc | | Oil Operator | Nov 2024 |
| 309 | Production Funds Inc | | Oil & Gas Operator | Nov 2001 |
| 310 | Production Gauging Service Inc | | Oil Operator | Feb 1999 |
| 311 | Production Management Corp. | | Oil & Gas Operator | Jul 1987 |
| 312 | Proex Energy Management, L.L.C. | Spring, TX 77386 | Oil & Gas Operator | Mar 2025 |
| 313 | Professional Petr. Servs, Inc. | | Oil Operator | Oct 2016 |
| 314 | Progenies Operating LLC | Austin, TX 78746 | Oil & Gas Operator | Mar 2025 |
| 315 | Progress Petroleum Co. | | Oil & Gas Operator | Apr 1993 |
| 316 | Project Design Specialists Inc | | Oil & Gas Operator | May 1991 |
| 317 | Prospective Investment & Trding Co LTD | | Oil & Gas Operator | Sep 2012 |
| 318 | Prosper Energy Corporation | | Oil & Gas Operator | Oct 1988 |
| 319 | Prospera Energy, Inc. | | Oil & Gas Operator | Dec 2005 |
| 320 | Prostar Energy, LLC | | Oil Operator | Sep 2011 |
| 321 | Proteus Petroleum, Inc. | | Oil & Gas Operator | Nov 1983 |
| 322 | Proton Energy, L.L.C. | Houston, TX 77002 | Oil & Gas Operator | Jun 2005 |
| 323 | Proven Fuel Exploration, Inc. | | Oil & Gas Operator | Mar 2022 |
| 324 | Proven Oil Production | | Oil Operator | Mar 2002 |
| 325 | Prudential Oil & Gas, Inc. | | Oil & Gas Operator | Jul 1987 |
| 326 | Prudential Petroleum Co., LTD. | | Oil & Gas Operator | Dec 1990 |
| 327 | Pruet & Hughes Co. | | Oil & Gas Operator | Jan 1978 |
| 328 | Pruet Production Co. | Jackson, MS 39201 | Oil & Gas Operator | Dec 2024 |
| 329 | Pryme Energy, LLC | | Oil & Gas Operator | Feb 2015 |
| 330 | PSC Industrial Outsourcing, LP | | Oil Operator | Dec 2024 |
| 331 | PSM Oil Production LLC | | Oil Operator | Jan 2025 |
| 332 | Pullco Services LLC | | Oil Operator | Dec 2024 |
| 333 | Puma, Inc. | | Oil & Gas Operator | Oct 2000 |
| 334 | Pure Resources, L.P. | Midland, TX 79701 | Oil & Gas Operator | Mar 2006 |
| 335 | PV Of MS Inc | | Oil & Gas Operator | Jan 2019 |
| 336 | PXP Gulf Coast Inc. | Houston, TX 77002 | Oil & Gas Operator | Mar 2015 |
| 337 | PXP Louisiana L.L.C. | | Oil & Gas Operator | Nov 2010 |
| 338 | Pyramid Petroleum, Inc. | | Oil & Gas Operator | May 1992 |
| 339 | Pyramid Petroleum, Inc.-La Div | | Oil Operator | Jun 1997 |
| 340 | Pyro Energy Corp | Kingwood, TX 77339-2102 | Oil & Gas Operator | Mar 1998 |