GEYSER: 3D thermo-hydrodynamic reactive transport numerical simulator including porosity and permeability evolution using GPU clusters

Abstract

GEYSER, an acronym for Graphic processing units (GPU) cluster computing for Enhanced hYdrothermal SystEms with Reactive transport, is a 3D simulator that includes porosity and permeability evolution for mass and heat transport processes in fractured geological media. The simulator also includes mass porosity and permeability evolution in response to dehydration reactions of hydrous minerals. GEYSER utilizes a finite difference scheme to solve the governing PDEs associated with 3D large-scale hydrothermal systems or geothermal reservoirs. This tool is a high performance code using GPU workstations or cluster technology. The physical processes implemented into the code are those associated with deep hydrogeological complexes where high fluid pressures generated by dehydration reactions can be sufficient to induce hydrofractures that significantly influence the porosity and permeability structures within geological formation. The governing equations are described and implemented and applied to a simplified 3D model of a magmatic intrusion at depth underlying a deep sedimentary cover. Close to ideal, weak scaling is demonstrated on GPU clusters with up to 128 GPUs. The numerical model can be used to investigate and understand coupled and time-dependent hydromechanical and thermodynamic processes at high resolution of the 3D computational domain. Applications include the hydrogeology of volcanic environments or exploitation of sediment-hosted geothermal resources. The code can also be suited for porosity and permeability evolution regarding pressure and temperature reaction rate to rock decarbonization for CO2 sequestration in deep sedimentary formations.