The Effects of Structural Lineament Reactivation on Antrim Shale Natural Gas Development
The Upper Devonian Antrim Shale Formation consists of an organic rich, highly fractured, black argillaceous mudstone of relatively low thermal maturity and is the source for major unconventional shale gas reservoirs within the Michigan Basin. Biogenic gas development was attributed to microbial activity stimulated by large volumes of glacial melt water transported through glacial channels and tunnel valleys. The Antrim Shale has proved significant economic viability with the total cumulative gas production reaching +3.39 TCF by the end of 2014. Deep-seated structural lineaments and basements faults within the Michigan Basin have experienced multiple episodes of fault-reactivation and hydrothermal fluid dispersion. Examination of the Traverse Formation's stratigraphic distribution revealed significant variability in the subsurface relief that is postulated to originate from flower structures that resulted from hydrothermal fluid transmission proximal to structural lineaments. These reactivation events not only propagate fracture network development, but also the migration of hot saline basinal brines. The dissemination of excess Cl- can significantly influence biogenic gas production in the Antrim Shale. Advances in spatial analysis technology provide new insights on the geospatial relationship between basinal brine chemistry proximal to structural lineaments and the overall influence on natural gas production. Utilizing an integrated geospatial dataset consisting of geochemical, wireline, structural, stratigraphic, and satellite data it was possible to examine the geospatial controls on biogenic gas development. Ultimately, this study aims to provide valuable insights on natural gas development, distribution, and accessibility through geospatial analysis of the intrinsic and extrinsic geological influences on the Antrim Shale Formation.
AAPG Datapages/Search and Discovery Article #90218 © 2015 Eastern Section Meeting, Indianapolis, Indiana, September 20-22, 2015