Acidic Geothermal Fluids Containing Hydrochloric Acid: A Review

Abstract

The occurence of HCI as the main acid compound in geothermal fluids is found in two environments. In geothermal fields related to andesitic volcanism it occurs as a relict of partially neutralized magmatic fluid that has not reacted with rock minerals suficiently to have all HCI converted to NaCl dissolved in geothermal fluid It also occurs where high-temperature brine with or without halite is vaporized to superheated steam which follows a dry (without liquid water) pathway to producing wells. These origins have been discussed extensively in the literature which is reviewed here.