Figure 2. Supercritical reservoirs are related to conventional geothermal resources by fluid mixing.

A passive tracer methodology was implemented to trace the flow fluid heated to supercritical conditions through the geothermal system. Colour scale indicates mixing (in terms of mass fraction) of fluid ascending out of the supercritical reservoir (mass fraction 1, red) and cooler liquid and/or vapour (grey tones). Results for the simulations shown in a (Fig. 1d) and b (Fig. 1e). Fluid specific enthalpy contours are shown with red dashed lines.