Thermo-hydraulic drivers of superhot geothermal well performance

Geothermal wells drilled into superhot (>375 °C) conditions have the potential to produce substantially more power than conventional geothermal wells. However, the interplay between reservoir pressure, temperature and permeability in controlling deliverable power remains poorly understood. Using a coupled reservoir-wellbore modeling framework calibrated against IDDP-1 discharge data, this study quantifies single-well power generation potential across a wide spectrum of superhot conditions, ranging from low-pressure (15 MPa) preserves single-phase conditions, reducing risks resulting from liquid condensation in the wellbore and enabling more efficient power conversion. Reservoir temperatures of 450–500 °C maximize power output, beyond which declining mass flows due to lower fluid density overwhelm enthalpy gains. Moreover, achieving power generation >30 MWe per well requires reservoir transmissivities on the order of 1000 md·m. Calibration against IDDP-1 discharge data indicates that values of this magnitude can occur in superhot rock, although they have yet to be deliberately engineered. These findings provide quantitative guidance for targeting and developing superhot resources, demonstrating that reservoir pressure and permeability may be more critical than simply pursuing maximum temperature, though realizing the pressure advantage requires sufficient permeability to sustain flow.