Modelling of Acid Fluid Wellbore Chemistry and Implications for Utilisation

Abstract

Thermodynamic models have been developed to calculate the chemistry of an acid geothermal well inflow from measured surface chemistry and enthalpy. This information, together with wellbore simulation, allows the calculation of chemical conditions throughout the wellbore. The results obtained are modelled as potential-pH Pourbaix type diagrams, describing corrosion product stability, to aid in the development of guidelines for materials suitable for utilisation of deep and acidic geothermal resources. These models, together with experimental and theoretical assessment of volcanic and acidic well fluids, advance the understanding of fluid chemistries and corrosion mechanisms for a range of engineering alloys that might be used for energy production fiom such fluids.