Influence of Coal Shrinkage and Swelling on Coalbed-Methane Production and CO2 Sequestration

摘要

The potential for enhanced methane (CH4) production and geologic sequestration of carbon dioxide (CO2) in unmineable coal seams needs to be evaluated before large-scale sequestration projects are undertaken.Coal is known to competitively adsorb CO2 and CH4 gases.Laboratory experiments indicate that coal swells when a gas is adsorbed and shrinks when a gas is desorbed.The swelling and shrinkage may change the coal-cleat porosity and permeability.A 3D swelling and shrinkage model (SSM) was developed that is based on equations that account for coupled fluid-pressure/-deformation behavior of a porous medium that undergoes swelling and shrinkage.