SCALING AND CORROSION IN AN EXPERIMENTAL GEOTHERMAL POWER PLANT.

The scaling and corrosion observed during the operation of the SDG&E/US ERDA Geothermal Loop Experimental Facility on high salinity geothermal fluids are described. In general scaling occurred on all surfaces in contact with the geothermal fluids with the severity increasing as the temperature of the fluid declined. Composition ranged from a predominantly metal sulfide deposition in the first stage to a predominantly silica deposition in the latter stages and reinjection system. Heaviest deposits were observed just down stream of the injection pump. Corrosion of the mild steel vessel and piping has been low, possibly because of the reducing environment and protection by the scale deposits.