Case Histories and Chemical Surveys Across Appalachian Reservoirs

J. Edward Tillman

Over 60,000 measurements of hydrocarbon microseepage have been made in hundreds of surveys over reservoirs and prospects in the Appalachians. The results reveal that most discrete reservoirs produce distinct zones of microseepage over or on the edges of the reservoir. As a result, these zones, if accurately understood, can be used to locate reservoirs, test prospects, and direct developmental drilling programs.

The geochemical signatures of these reservoir-related zones of microseepage, however, are commonly complex and require adequate coverage, appropriate techniques, and thorough geochemical model development. Case histories of surveys over Oriskany, Trempeleau, Onondaga, Upper Devonian, and other pay zones reveal the importance of fully incorporating reservoir specific geochemical data and expertise into all phases of an exploration program. These case histories illustrate the type of signals and the strength of the anomalies over a variety of Appalachian reservoirs.

AAPG Search and Discovery Article #91031©1988 AAPG Eastern Section, Charleston, West Virginia, 13-16 September 1988.