Underground carbon dioxide (CO2) storage is a promising strategy to reduce atmospheric greenhouse gas emissions. However, the injection of cool CO2 alters the thermohydromechanical equilibrium, including pressure variation, rock deformation, stress redistribution, and thermal gradients that destabilize geological faults. The most critical risks associated with cool CO2 injection can include fault slip, induced seismicity, and leakage pathways, as reported in some field operations1. A simplified one-way coupling strategy often underestimates THM interactions, while the fully implicit approach provides accurate results but is computationally expensive and unviable for field-scale applications. Sequential coupling schemes emerge as a viable alternative by iteratively exchanging thermal, hydraulic, and mechanical coupling parameters2. This work investigates sequential coupling strategies for assessing the potential risk of fault reactivation in CO2 geological sequestration. Geological faults are modelled using zero-thickness interface elements with the Mohr-Coulomb criterion to assess reactivation mechanisms. Fault permeability evolution is linked to stress and thermal changes to determine the maximum sustainable injection pressure. The numerical results are compared against those using the fully implicit approach in synthetic reservoirs. Parametric study investigates the impact of fault permeability evolution, thermal effects, and mesh refinement on the maximum injection pressure. The numerical results demonstrate that the sequential coupling strategy accurately predicts fault reactivation and the maximum injection pressure while substantially reducing computational costs. These findings provide valuable insights for efficient field-scale THM modelling in CO2 sequestration.