| 1 | P.C.S.I. | | Oil & Gas Operator | Jun 1987 |
| 2 | Pan-Ok Production Company | | Oil & Gas Operator | Nov 2024 |
| 3 | Par Minerals Corporation | Shreveport, LA 71101 | Oil & Gas Operator | Dec 2025 |
| 4 | Parker & Parsley Petroleum Co. | | Oil & Gas Operator | Dec 1990 |
| 5 | Partners Oil Company | Tulsa, OK 74135 | Oil & Gas Operator | Aug 1995 |
| 6 | Pel-Tex Oil Company, Inc. | | Oil & Gas Operator | Jul 1995 |
| 7 | Perdido Energy Louisiana, LLC | | Oil & Gas Operator | Dec 2024 |
| 8 | Perdura Energy L.L.C. | | Oil & Gas Operator | Apr 2018 |
| 9 | Petrocana,Inc. | | Oil & Gas Operator | Aug 1993 |
| 10 | Petrodome Operating, LLC | Houston, TX 77265 | Oil & Gas Operator | Jun 2025 |
| 11 | Petroquest Energy, L.L.C. | Lafayette, LA 70505 | Oil & Gas Operator | Dec 2025 |
| 12 | Petroreal Inc. | Temple, TX 76503 | Oil & Gas Operator | Dec 2025 |
| 13 | Pharaoh & Associates, Inc. | Houston, TX 77252 | Oil & Gas Operator | Aug 2002 |
| 14 | Phillips Oil Company | Casper, WY 82602 | Oil & Gas Operator | Sep 1986 |
| 15 | Phillips Petroleum Company | Houston, TX 77251 | Oil & Gas Operator | Mar 2013 |
| 16 | Phoenix Exploration Company LP | | Oil & Gas Operator | Sep 2011 |
| 17 | Phoenix Oil & Gas LTD., L.L.P. | Houston, TX 77010 | Oil & Gas Operator | Jun 2004 |
| 18 | Pickens Company, Inc., The | Dallas, TX 75225 | Oil & Gas Operator | Jan 2025 |
| 19 | Pilot Resources, Inc. | | Oil & Gas Operator | May 2013 |
| 20 | Pioneer Exploration Company | Houston, TX 77090 | Oil & Gas Operator | Sep 2025 |
| 21 | Pioneer Exploration, LLC | Houston, TX 77090 | Oil & Gas Operator | Oct 2025 |
| 22 | Pioneer Exploration, LTD. | Houston, TX 77090 | Oil & Gas Operator | Sep 2008 |
| 23 | Pioneer Prod. Corp. | | Oil & Gas Operator | Jun 1986 |
| 24 | Plains Resources Inc. | Houston, TX 77002 | Oil & Gas Operator | Jul 2008 |
| 25 | Plano Corp. | | Oil & Gas Operator | Mar 2005 |
| 26 | Plymouth Resources Group II Inc | | Oil & Gas Operator | May 2007 |
| 27 | Pogo Producing Company | Houston, TX 77002 | Oil & Gas Operator | Jan 2008 |
| 28 | Polaris Enterprises Inc | Houston, TX 77057 | Oil & Gas Operator | Oct 1998 |
| 29 | Power Reserves, Inc. | | Oil Operator | Feb 1999 |
| 30 | Prairie Producing Company | | Oil & Gas Operator | Dec 1992 |
| 31 | Prayer Oil & Gas Production, LLC | Hallsville, TX 75650 | Oil & Gas Operator | Dec 2025 |
| 32 | Premience Energy LLC | | Oil & Gas Operator | Dec 2024 |
| 33 | Presidio Exploration, Inc. | Englewood, CO 80155 | Oil & Gas Operator | May 1999 |
| 34 | Puma, Inc. | | Oil & Gas Operator | Oct 2000 |
| 35 | PXP Gulf Coast Inc. | Houston, TX 77002 | Oil & Gas Operator | Mar 2015 |
| 36 | PXP Louisiana L.L.C. | | Oil & Gas Operator | Nov 2010 |