Fracturing in coals with different fluids: an experimental comparison between water, liquid CO2, and supercritical CO2

The present work conducted laboratory experiments of fracturing in fat coals, anthracites, and mudstones. Three different fluids were selected as the fracturing fluids, including water, liquid CO2 (L-CO2), and supercritical CO2 (Sc-CO2). The resulting fracture morphologies and fracture apertures of the coal specimens were investigated using 3D morphological scanning, and the permeabilities of the samples were measured before and after...