Fully coupled thermal-hydro-mechanical model for ScCO2 storage in shale gas reservoirs

This study explores the potential of using supercritical CO2 (ScCO2) injection for carbon sequestration in shale gas reservoirs, focusing on the impact of structural heterogeneities on CO2 storage. This investigation presents a fully coupled thermohydro-mechanical (THM) analysis of ScCO2 injection in such reservoirs, aiming to unravel the complexities imposed by multiscale structural heterogeneities on the process of ScCO2 sequestration, encompassing the intricate shale matrix and the discrete fracture network. The model incorporates a fractal-based paradigm for accurately delineating shale matrix porosity and the evolution of pore diameters, which are instrumental in refining the permeability model within these geologically complex structures. The model considers the unique properties of ScCO2 and uses the Navier-Cauchy equation to simulate the mechanical behavior of shale formations during ScCO2injection. A thorough sensitivity analysis assesses the influence of various factors, such as injection pressure, temperature and principal stresses, on the process's efficiency. Our findings aim to improve carbon capture and storage (CCS) techniques, contributing to NetZero goals by optimizing ScCO2 sequestration in unconventional reservoirs.