Abstract
Abstract Due to heavy industrialization and ongoing fossil fuel burning, CO2 emissions have been a major contributor to climate change and enhanced greenhouse gases. The growing public concern motivates considerable study towards discovering an efficient technique of managing and lowering the emission amounts, and CO2 collection and subterranean storage have been presented as viable alternative. In order to assess the geomechanical behavior of the multilayered In Salah CO2 storage site, a two-dimensional finite element model of fault activation processes in the context of CO2 storage was conducted. It is 4 km wide and 2 km deep and includes the key domains and formations (overburden, main caprock, lower caprock, and underburden). The simulation results suggest that the influence of fault reactivation under base pressure of 32 MPa causes peak vertical deformation of 0.044 m in the caprock and 0.015 - 0.020 m displacement at the surface layers. The obtained modelling results are in agreement with InSAR monitoring results conducted at the site. The geomechanical model was moderately sensitive to a decrease in the effective stress ratio and fault dip angle. The scenario with k = 0.5 performed a considerable displacement reduction compared to the benchmark run. The simulation with a 30° fault angle demonstrated a more pessimistic outcome with a larger displacement field, which could heighten the risks associated with the low-angle faults in the areas of high horizontal stress distribution.