Geochemical Modelling of Low-Temperature Geothermal Fields from Bihor County, Romania

The main geothermal zone in Romania is situated along the western border of the country, from Satu Mare in the north to Timisoara in the south. Considering the wellhead temperatures of the waters, the geothermal areas are classified as low-temperature and medium enthalpy. The Bihor County, located in the north-western side, with its high geothermal potential has supplied heating both for residential and commercial spaces, industrial processes and for balneal purposes. Chemical study for the characterization of the geothermal waters and water-rock interaction is of great significance both before the operation and during the geothermal well production. For the evaluation of the geochemical structure of the fields, fluid samples were obtained from several wells. Using the analytical data of the wellhead samples, the aquifer fluids feeding the selected wells from Bihor were modelled with the aid of speciation program WATCH. The modelled aquifer fluids assessed how closely they have reached to equilibrium conditions with respect to mineral-solution reactions that may occur in the reservoir.