Differential swelling and permeability change of coal in response to CO2 injection for ECBM

Carbon dioxide gas permeability of coal core samples and estimation of fracture aperture width

“…Anisotropic shrinkage effects are discussed. Mazumder and Wolf (2008) noted that the matrix volume of coal swells when CO 2 /CH 4 adsorb on the coal structure. In coalbed gas reservoirs, matrix swelling could cause the fracture aperture width to decrease, causing a considerable reduction in permeability.…”

“…Coal can be understood as a macromolecular cross-linked polymeric structure. Mazumder and Wolf (2008) have been investigated an experimental effort to measure the differential swelling effect of CO 2 /CH 4 on this macromolecular structure and to theoretically translate that effect in terms of porosity and permeability. A unique feature of this work is that, real time permeability measurements were done to see the true effect of differential strain from CH 4 saturated coal core flooding experiments.…”

Effect of brine-CO2 fracture flow on velocity and electrical resistivity of naturally fractured tight sandstones

“…The significant drop in the fracture permeability during water injection is probably related to the matrix swelling and volumetric strain impact, which caused the relative closure and reduction of fracture aperture. In the more plastic rocks such as coal and organic-rich shale, matrix swelling (volumetric strain) can even result in permanent closure of fracture apertures (Mazumder and Wolf, 2008;Liu and Rutqvist, 2010). Injection of gaseous CO 2 dried the water out of the sample (Fig.…”

Linking gas-sorption induced changes in coal permeability to directional strains through a modulus reduction ratio

“…A surrogate of this case is powdered coals where for powdered high volatile bituminous Pennsylvanian coals the adsorption rate decreases with increasing grain size for all experimental conditions (Busch et al, 2004). Similarly, coal type and rank (Robertson and Christiansen, 2007;Prusty, 2007) influences the preferential sorption behavior and the evolution of permeability with these changes is linked to macromolecular structure (Mazumder and Wolf, 2008). Adsorption kinetics may also be determined for various gases (e.g.…”