Silica in Cerro Prieto Geothermal Field

Abstract

Water-steam mixtures from geothermal reservoirs carry gaseous and solids chemical species (carbon dioxide, hydrogen sulfide, sodium and potassium carbonates, sodium and potassium chlorides, silica, etc.) Their distribution and quantity are dependent from reservoir temperatures and its geochemical structure. In liquid-dominant geothermal resources operating in steam/brine separation systems, the physical-chemical equilibrium is broken producing a critical situation about silica behavior. Silica solubility falls rapidly forming colloidal solutions which are difficult to separate, or else silica deposition is presented with a range of problems in systems operation, brine energy uses, or reinjection processes. The objective of this paper is the silica problem analysis in Cerro Prieto area at Geothermal field in Mexicali, Baja California, Mexico.