Preliminary notes on the acid fluids of the Miravalles geothermal field (Guanacaste, Costa Rica)

Four of the wells drilled for production (PGM-02, PGM-06, PGM-07, PGM-19) in Miravalles geothermal field of Costa Rica discharge acid fluids. They are located along the eastern boundary of the field close to the Miravalles volcano. Analysis of the existing chemical and isotopic data for the acidic wells in comparison with those for the pH-neutral production wells and surface natural manifestations allowed us to refine the geochemical models of geothermal field present in the literature. Two types of acidic fluids, a shallower one and a deeper one have been postulated.