| 501 | Western Reserves Oil Co Inc | Midland, TX 79705 | Oil & Gas Operator | Oct 2020 |
| 502 | Western Reserves Oil Co Inc And Sullivan And Co | | Oil & Gas Operator | Jul 2001 |
| 503 | White Pine Production LLC | | Oil & Gas Operator | Oct 2025 |
| 504 | White River Production LLC | | Oil Operator | Nov 2025 |
| 505 | White Rock Oil & Gas, LLC | Plano, TX 75024 | Oil & Gas Operator | Dec 2025 |
| 506 | Whiting Oil And Gas Corporation | Houston, TX 77002 | Oil & Gas Operator | Dec 2025 |
| 507 | Whitney Oil And Gas Corp | | Oil & Gas Operator | Oct 1988 |
| 508 | Wicklund Enterprises Inc | | Oil Operator | Dec 2024 |
| 509 | Winterfield Corp | | Oil Operator | Nov 2024 |
| 510 | Wiser Oil Co | Denver, CO 80202 | Oil & Gas Operator | Dec 2023 |
| 511 | Wisley Robert | | Oil & Gas Operator | Dec 1994 |
| 512 | Wolverine Environmental Production Inc | | Oil & Gas Operator | Sep 2000 |
| 513 | Wolverine Gas And Oil Company Of Michigan LLC | | Oil & Gas Operator | Oct 2025 |
| 514 | Yost Energy Inc | | Oil & Gas Operator | Nov 2025 |
| 515 | Yost Richard D Dba Yost Inc | | Oil Operator | Aug 2024 |