Exploring for supercritical geothermal resources through integrated numerical modeling

Geothermal resources at superhot temperatures (T>374°C) offer exceptional energy potential but generally require proximity to active magmatic heat sources. Numerical simulations show that while shallow boiling zones and elevated heat fluxes may persist for tens of thousands of years after an intrusion cools, supercritical conditions are comparatively short-lived, meaning the presence of a high-enthalpy system alone is not diagnostic of supercritical resource potential. Where magmatic heat sources are present, permeability structure and fluid properties such as salinity and gas content are the primary control on resource accessibility. Production modeling of the IDDP-1 well at Krafla indicates near-magma permeabilities of ~10^-13 m², substantially higher than typically assumed for the brittle-ductile transition zone, and likely indicative of efficient stimulation due to cold-water injection during drilling. Yet detecting such conditions from the surface remains challenging. Deep electrical conductors imaged by magnetotellurics are often interpreted as indicators of high-temperature fluids or partial melt, but conductivity depends jointly on temperature, fluid salinity, porosity, and melt fraction, making interpretation of deep conductors ambiguous. Integrated numerical modeling coupling hydrothermal flow simulations with petrophysical forward models offers a pathway to discriminate between these scenarios and develop physics-based exploration guidelines for supercritical geothermal systems.