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

Abstract

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 of low-temperature and medium enthalphy. 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 balnear purpose as well. Before operation and during geothermal well production, a chemical study of the geothermal waters and water-rock interaction is of real importance. For 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 the speciation programs WATCH and also by SOLVEQ. The modelled aquifer fluids assessed how closely they have approached equilibrium conditions with respect to mineral-solutions reactions that may occur in the reservoir.