Evaluation of the mechanical behaviour of brine CO2 saturated brown coal under mono-cyclic uni-axial compression

Abstract

CO2-sequestration and ECBM techniques necessitate injection of CO2 into coal reservoirs that are saturated under various pore fluid conditions, resulting in alterations in mechanical properties. In this study, we evaluate the effect of pore fluid chemistry and the interaction time on the coal mechanical degradation. Uni-axial compressive strength (UCS) tests, ARAMIS photogrammetric analysis, micro-CT imaging, and Fourier transform infrared spectroscopy (FT-IR) are combinedly used to evaluate such alterations and to interpret the causative factors in water, water + CO2, 10% brine + CO2 and 20% brine + CO2 saturated coal. The results indicate that irrespective of the pore fluid chemistry, mech..