Predictions of calcite scaling location and amounts in geothermal reservoirs by coupled thermo-hydro-chemical model

Abstract

As one of the five non-carbon-based energy sources, geothermal energy plays a pivotal role in the transformation of energy system and the realization of the dual carbon goal. In view of rational geothermal reservoir development is of vital significance to the utilization efficiency of geothermal energy, the influences of rock physical properties and geothermal fluid properties caused by geothermal reservoir reconstruction on calcite scaling were investigated, and several conclusions were obtained: The amounts and areas of calcite scaling in the geothermal reservoirs significantly increase with running time; The amounts of calcite scaling in the geothermal reservoir adjacent to the well bottom increase conspicuously with permeability, Ca²⁺ and HCO₃^– concentrations, pH value of geothermal fluid, CO₂ mass flow rate, and decrease with salinity, which seriously restricts the utilization rate of geothermal wells. These results give a theoretical foundation and guideline for scaling prevention and production rising of geothermal wells.