Porosity estimation of a geothermal carbonate reservoir in the German Molasse Basin based on seismic amplitude inversion

Abstract The Molasse Basin is one of the most promising areas for deep geothermal exploitation in Germany and target horizon aquifer Upper Jurassic carbonates. Carbonate deposits can be very heterogeneous even over a small area due to diagenetic processes varying depositional environments. preferential targets carbonate are fault zones, reef facies karstified areas, since they expected act as hydraulically permeable zones high porosity permeability. Therefore, identifying these structures characterizing, e.g., their internal distribution importance. This accomplished using 3D reflection seismic data. Besides structural information, surveys provide important reservoir properties, such acoustic impedance, from which model derived. In our study Munich we carried out amplitude inversion get an impedance data set, corresponding geological model, logging six wells at ‘Schäftlarnstraße’ site. logs were than used calculate model. shows wide range 0 20% entire zone lithology along reveals that dolomitic limestone has highest porosities calcareous dolomite lowest porosities. cut by large W–E striking fault, Fault, footwall north it higher more intense karstification hanging wall south. Considering area, increase east west observed. Furthermore, identified complex buildups pinnacle reefs. cores have mostly low of, < 3% up 7 14% observed caps on slopes. slopes show characteristic interfingering with surrounding bedded facies, indicates syn-sedimentary development slightly build growth rates. We also assessed quality regard determined moderate good defining evaluation levels. maps rocks Berriasian Malm $$\zeta$$ ζ 1 exploitation, especially Fault wall, because characterized massive although latter mainly restricted