The Sokoria Geothermal System, Flores Island, Indonesia

Abstract

Abstract The Sokoria geothermal field is a typical volcano-hosted geothermal system with widely distributed thermal features including altered ground, fumaroles and bicarbonate-sulfate-chloride springs. The main resource is situated beneath the flanks of the Kelimutu Volcanic Complex on Flores Island, Indonesia. This complex is renowned for its three acidic crater lakes that change color from time to time. Recent exploration and drilling results at Sokoria indicate the existence of a medium to high enthalpy resource, in the range of 200-260\u2009°C, with slightly acidic fluids (pH 4.2 – 5.7) that have been sampled during flow testing of three wells without any physical evidence of corrosion of the surface facilities or the wellhead. Stable isotope data from these waters lie on or near the world meteoric line implying that the resource fluids as well as those from the different thermal waters are of meteoric origin typical of many geothermal systems. Initial testing results show that the first 5 MWe in the area can be commissioned by the end of 2019. This field could be developed to generate up to 30 MWe.