| 1 | Parker & Parsley Development L.P | Midland, TX 79702 | Oil & Gas Operator | Oct 2007 |
| 2 | Parker & Parsley Producing L.P. | Midland, TX 79702 | Oil & Gas Operator | Oct 1997 |
| 3 | Patrick Pet. Corp. Of Michigan | Houston, TX 77227 | Oil & Gas Operator | Aug 1995 |
| 4 | Penn VIrginia Oil & Gas Corp | Houston, TX 77024 | Oil & Gas Operator | Dec 2023 |
| 5 | Petro-Hunt Corporation | Dallas, TX 75201 | Oil & Gas Operator | Jun 2003 |
| 6 | Petro-Hunt, L.L.C. | Dallas, TX 75201 | Oil & Gas Operator | Oct 2025 |
| 7 | Petroquest Exploration, Inc. | Dallas, TX 75251 | Oil & Gas Operator | Mar 2008 |
| 8 | Pioneer Natural Res. USA, Inc. | Spring, TX 77389 | Oil & Gas Operator | Oct 2025 |
| 9 | Pioneer Resources Producing, L.P | Irving, TX 75039 | Oil & Gas Operator | Feb 2001 |
| 10 | Prentice Napier & Green Inc | Oklahoma City, OK 73142 | Oil & Gas Operator | Jul 2025 |