| 1 | P D Parker | | Oil & Gas Operator | Aug 1985 |
| 2 | P.C.S.I. | | Oil & Gas Operator | Jun 1987 |
| 3 | Parker & Parsley Development Co. | Midland, TX 79702 | Oil & Gas Operator | May 1995 |
| 4 | Parker & Parsley Petroleum Co. | | Oil & Gas Operator | Dec 1990 |
| 5 | Pelican Dome Exploration Inc | Harahan, LA 70123 | Oil & Gas Operator | Aug 2000 |
| 6 | Pennington Oil & Gas Int, LLC | | Oil & Gas Operator | Dec 2024 |
| 7 | Pennington Operating Company, LLC | | Oil & Gas Operator | Jul 2020 |
| 8 | Pine Island Operating, L.L.C. | Graham, TX 76450 | Oil & Gas Operator | Oct 2025 |
| 9 | Premier Natural Resources II,LLC | Tulsa, OK 74105 | Oil & Gas Operator | Feb 2015 |
| 10 | Presidio Exploration, Inc. | Englewood, CO 80155 | Oil & Gas Operator | May 1999 |