| 1 | Pacific Enterprises Oil Co. (USA) | Dallas, TX 75201 | Oil & Gas Operator | Feb 2001 |
| 2 | Pacific Enterprises Royalty Co | Oklahoma City, OK 73101 | Oil & Gas Operator | Feb 2002 |
| 3 | Paloma Natural Gas, LLC | Houston, TX 77002 | Oil & Gas Operator | Dec 2024 |
| 4 | Par Minerals Corporation | Shreveport, LA 71101 | Oil & Gas Operator | Oct 2025 |
| 5 | Par Oil Corporation | | Oil & Gas Operator | Sep 1990 |
| 6 | Pearl Resources Inc. | | Oil & Gas Operator | Jul 1990 |
| 7 | Pend Oreille Oil & Gas Company | | Oil & Gas Operator | Sep 1989 |
| 8 | Pennzenergy Explor & Prod LLC | | Oil & Gas Operator | Dec 1999 |
| 9 | Pennzoil Exploration & Production Co. | Carthage, TX 75633 | Oil & Gas Operator | Mar 2008 |
| 10 | Peoples Energy Prod.-TX, L.P. | Houston, TX 77002 | Oil & Gas Operator | Sep 2007 |
| 11 | Petro-Chem Operating Company, Inc. | Shreveport, LA 71101 | Oil & Gas Operator | Oct 2025 |
| 12 | Petro-Lewis Corp. | | Oil & Gas Operator | Feb 1994 |
| 13 | Petrohawk Operating Company | Houston, TX 77056 | Oil & Gas Operator | Oct 2021 |
| 14 | Petrosearch, Inc. | | Oil Operator | Jul 1992 |
| 15 | Phillips Energy, Inc. | Shreveport, LA 71101 | Oil & Gas Operator | Dec 2018 |
| 16 | Phillips Petroleum Company | Houston, TX 77251 | Oil & Gas Operator | Mar 2013 |
| 17 | Phoenix Operating Company, Inc. | Shreveport, LA 71161 | Oil & Gas Operator | Mar 2015 |
| 18 | Phoenix Opr Co Inc-Oc Yacht 85 | | Oil Operator | Dec 1992 |
| 19 | Phoenix Opr Co Inc-Rvside '85 | | Oil Operator | Dec 1992 |
| 20 | Pinnacle Operating Company, Inc. | Shreveport, LA 71135 | Oil & Gas Operator | Oct 2025 |
| 21 | Placid Oil Company | Houston, TX 77227 | Oil & Gas Operator | Mar 2008 |
| 22 | Pogo Producing Company | Houston, TX 77002 | Oil & Gas Operator | Jan 2008 |
| 23 | Premier Natural Resources II,LLC | Tulsa, OK 74105 | Oil & Gas Operator | Feb 2015 |
| 24 | Pritchard Engineering | | Oil & Gas Operator | Mar 1989 |