Fault Reactivation Can Generate Hydraulic Short Circuits in Underground Coal Gasification—New Insights from Regional-Scale Thermo-Mechanical 3D Modeling

摘要: Underground coal gasification (UCG) has the potential to increase worldwide reserves by utilization of deposits not mineable conventional methods. This involves combusting in situ produce a synthesis gas, applicable for electricity generation and chemical feedstock production. Three-dimensional (3D) thermo-mechanical models already significantly contribute UCG design process optimization mitigation environmental footprint. We developed first 3D model based on real structural geological data investigate impacts using isothermal non-isothermal simulations, two different pillar widths four varying regional stress regimes spatial changes temperature permeability, ground surface subsidence fault reactivation. Our simulation results demonstrate that processes have be considered these assessments due thermally-induced stresses. Furthermore, we permeability is limited close reactor vicinity, although presence previously undetected faults can introduce formation hydraulic short circuits between single channels over large distances. requires particular consideration potentially present sub-seismic exploration site selection stages, since required may easily underestimated with orientations respect regime.