| 1 | Panhandle Oil & Gas Inc | Oklahoma City, OK 73112-5688 | Oil & Gas Operator | May 2007 |
| 2 | Patterson Petroleum LLC | Snyder, TX 79550 | Oil & Gas Operator | Oct 2007 |
| 3 | Patterson Petroleum LP | Snyder, TX 79550 | Oil & Gas Operator | Mar 2008 |
| 4 | Patterson Petroleum, Inc. | Snyder, TX 79550 | Oil & Gas Operator | Feb 2000 |
| 5 | Peoples Energy Prod.-TX, L.P. | Houston, TX 77002 | Oil & Gas Operator | Sep 2007 |
| 6 | PG&E Resources Company | Houston, TX 77042 | Oil & Gas Operator | May 1995 |
| 7 | Pickens Company, Inc., The | Dallas, TX 75225 | Oil & Gas Operator | Feb 2024 |
| 8 | Pierce Operating Company, L.L.C. | Bryan, TX 77808 | Oil & Gas Operator | Dec 2018 |
| 9 | Pioneer Natural Res. USA, Inc. | Irving, TX 75038 | Oil & Gas Operator | Apr 2024 |
| 10 | Plains Production Inc | Wichita Falls, TX 76308 | Oil & Gas Operator | Dec 1995 |
| 11 | Premier Natural Resources II,LLC | Tulsa, OK 74105 | Oil & Gas Operator | Feb 2015 |
| 12 | Prime Western Development, Inc. | Dallas, TX 75230 | Oil & Gas Operator | Dec 1998 |
| 13 | Proline Energy Resources Inc | Sugar Land, TX 77479 | Oil & Gas Operator | Apr 2024 |