Outcrop Analogue Studies in Geothermal Exploration – ‘AuGE’ Project

Abstract

Despite its undoubted deep geothermal potential projects in the Upper Rhine Graben and successful deep drillings are scarce compared with other geothermal regions in Germany (e.g. the Molasse Basin). The current paper introduces the joint research project ‘Outcrop Analogue Studies in Geothermal Exploration – AuGE’. The project aims to develop standardized workflows for outcrop analogue studies tailored to the needs of geothermal exploration. This will improve predictions of flow rate and heat transfer within the reservoir and decrease both exploration risk and cost to encourage geothermal project development within this region. Project partners are the Universities of Erlangen, Goettingen and Heidelberg as well as the industrial partners GeoEnergy and GeoThermal Engineering. The project is funded by the German Federal Ministry for the Environment, Nature Conservation and Nuclear Safety (BMU) within the framework of the 5th Energy Research Programme (FKZ 0325302). The geologic structure of the Upper Rhine Graben exhibits deeply buried sediments within the centre of the Graben that are also exposed on the Graben shoulders within short distances. This offers ideal conditions for outcrop analogue studies. The applied multi-method approach combines (i) lithofacies analysis and determination of petrophysical properties, (ii) examination of diagenetic processes, (iii) characterization of fault zones, (iv) LiDAR based 3D reservoir modelling, (v) seismic attribute analysis and (vi) analysis of well data. Results will be integrated in ‘shared earth models’ enabling to conduct reservoir thermo-hydraulic simulations to predict fluid flow and heat transport for varying production scenarios. The extensive integration of methods applied and their implementation in geothermal exploration strategies enhances thermo-hydraulic simulations and therefore the reliability of predictions of both flow rate and heat transport. This will significantly reduce not only exploration risk but also cost and contribute to expand the development of geothermal projects in the Upper Rhine Graben.