Prediction of permeability reduction due to silica scale deposition with a geochemical clogging model at Sumikawa Geothermal Power Plant

In experiments, flow rates through porous media were measured using raw brine (pH = 6.5, [SiO₂] = 1130 mg/L) at Sumikawa Geothermal Power Plant in 2016. The flow rates decreased by up to 25% of the initial flow rate after 11 days. A geochemical clogging model with data from 2003 was used to predict the permeability reduction due to silica precipitation. This model considers the type of silica deposited (amorphous and aluminum–silica scales) and calculates the optimized conditions for keeping the concentration of SiO₂ below 300 mg/L to lessen the reduction of permeability during the reinjection of geothermal brines.