Abstract

Recent success in the Pardue West Field, located in northeastern Fisher County, Texas on the Eastern Shelf of the Permian Basin has sparked a renewed interest in the drilling of exploration wells in a moderately mature area. The Marshall R. Young discovery well was drilled as an Ellenburger test based on a seismic lead. This well proved productive in the Ellenburger Dolomite and the Swastika Sandstone. In the last thirty years before the discovery well, eight dry holes had been drilled within one mile of the prospective area (six Ellenburger tests and two Palo Pinto tests).

Techniques utilized in the development of the field included analysis of insoluble residues, audio magneto-tellurics, dip meter data and pressure data. Subsurface maps were constructed to determine depositional trend directions for each formation. In prospecting for the Ellenburger, the most useful maps were a top of Ellenburger by insoluble residues and a subcrop map of the various insoluble zones. The most valuable maps for the Palo Pinto Limestone were structure and isopach maps of the formation. Delineating the Swastika Formation required mapping on the base of the overlying Ivan Limestone and a net pay isopach map of the sand.

As of October 1989, eight Ellenburger tests have been drilled with only two dry holes (75% success rate); and two producing Palo Pinto wells are recent plugbacks from the Ellenburger Formation. The estimated ultimate recovery from all formations is 900,000 barrels of oil.