Potential for Petroleum Production in Mississippian-Pennsylvanian Paleovalleys in the Main Consolidated Field (Crawford County, Illinois) and Application throughout the Illinois Basin

London, Jeremy; Reeder, Andrew; May, Michael T.

Paleovalleys associated with the Mississippian-Pennsylvanian uncomformity have been identified as unconventional targets for potential hydrocarbon exploration in the Illinois Basin. The extent to which the paleovalleys have been explored and exploited for hydrocarbons is largely undocumented.

The Main Consolidated Field in Crawford County, Illinois has produced hydrocarbons from a basal Pennsylvanian reservoir occurring in lenticular conglomeratic sand bodies. Major pay zones in this field include Pennsylvanian sandstones, such as the Robinson, and older Chesterian zones as well. Due to the discrete nature of the channel sands and the difficulty in identifying the Mississippian-Pennsylvanian unconformity, these paleovalley traps may go unnoticed.

Much work has been done to identify the Mississippian-Pennsylvanian disconformity, characterize the Chesterian and basal Pennsylvanian Caseyville lithology, and delineate the pre-Pennsylvanian paleovalleys in the Illinois Basin. This study explores the potential for hydrocarbon production from Mississippian-Pennsylvanian paleovalleys in the Main Consolidated Field in Crawford County, Illinois and its implications throughout the basin.

AAPG Search and Discovery Article #90163©2013AAPG 2013 Annual Convention and Exhibition, Pittsburgh, Pennsylvania, May 19-22, 2013