Stress-dependent fracture porosity and permeability of fractured coal: An in-situ X-ray tomography study

Abstract

Coal porosity and permeability are highly stress-sensitive. Although the stress-dependent permeability behaviour of coal has been well documented in the literature, few studies are available which directly observe the dependency of fracture aperture, porosity and connectivity on effective stress. In this study, in-situ X-ray tomography was conducted using a novel X-ray transparent tri-axial core holder to provide a detailed characterization of coal fracture network evolution due to increased effective stress. Both conventional and synchrotron X-ray sources were used to image two fractured anthracite coals (named sample A and sample B) at resolutions of 38.7 and 18.1 μm, respectively. Permeab..