24-10-2012, 03:25 PM
Analysis of Devonian Black Shales in Kentucky for Potential Carbon Dioxide Sequestration and Enhanced Natural Gas Production
ABSTRACT
CO(sub 2) emissions from the combustion of fossil fuels have been linked to global climate change. Proposed carbon
management technologies include geologic sequestration of CO(sub 2). A possible, but untested, sequestration strategy is to
inject CO(sub 2) into organic-rich shales. Devonian black shales underlie approximately two-thirds of Kentucky and are
thicker and deeper in the Illinois and Appalachian Basin portions of Kentucky than in central Kentucky. The Devonian black
shales serve as both the source and trap for large quantities of natural gas; total gas in place for the shales in Kentucky is
estimated to be between 63 and 112 trillion cubic feet. Most of this natural gas is adsorbed on clay and kerogen surfaces,
analogous to methane storage in coal beds. In coals, it has been demonstrated that CO(sub 2) is preferentially adsorbed,
displacing methane. Black shales may similarly desorb methane in the presence of CO(sub 2). The concept that black,
organic-rich Devonian shales could serve as a significant geologic sink for CO(sub 2) is the subject of current research. To
accomplish this investigation, drill cuttings and cores were selected from the Kentucky Geological Survey Well Sample and
Core Library.