Unterhaching geothermal well doublet: structural and hydrodynamic reservoir characteristic; Bavaria (Germany)

Abstract

At Unterhaching, two wells – Gt Uha1a for production, Gt Uha2 for injection – were drilled and tested for the cogeneration of electricity and heat. Very high productivities of both could be determined. These good inflows are attributed to the influence of fault systems. In particular, the well Gt Uha2 was drilled through a fault with a vertical throw of 238 m. At the top of the aquifer, the temperature of the produced water was 123 °C (Gt Uha1a) or approx. 134 °C (Gt Uha 2). The high temperatures in the Gt Uha2 well are ascribed to waters circulating in a deepreaching fault system. Inflows within the Malm come exclusively from the Upper Malm (Malm Zeta).