Integrated Geochemical and Structural Analysis of a Breached Reservoir in the Northeastern Pennsylvania Marcellus Shale

The Middle Devonian Marcellus Shale Formation in northeastern Pennsylvania provides a unique opportunity to study the effects of natural fractures and faults on hydrocarbon migration in tight, shale-gas reservoirs using noble gas geochemistry. The primary purpose of this study is to illustrate the utility of noble gas geochemical data in determining the mechanism of hydrocarbon migration on a locally breached structure. This can have implications in other structurally complex tight gas fields, where the effects of faulting and fracturing are still uncertain regarding their impact on reservoir quality and seals. This study concludes that partially open, conductive fractures are responsible for the breached Marcellus Shale reservoir located atop the Granville anticline structure in northeastern Pennsylvania. This conclusion is supported primarily by noble gas geochemical and Formation MicroImager (FMI) log analyses. This research integrates additional data obtained from Chief Oil & Gas, such as petrophysical, seismic, core, produced water chemistry, and geothermal data, in order to wholistically define the local breaching mechanism and how it relates to interpreted subsurface features. This research ultimately sheds light on one of the major outstanding issues identified in the Marcellus Shale play, which is the identification where faults and fractures either enhance production or degrade reservoir seal quality