The COTHERM project aims at a better understanding of the subsurface processes in natural high-temperature geothermal systems that are becoming an attractive alternative energy resource. Such systems form when groundwater is flowing around a magma body at depth, gets heated and then rises to the surface. How long the geothermal system is active and how much energy the fluid carries depends mostly on the depth and size of the magma body and on the permeability of the surrounding rocks. Both are difficult to assess from the surface without dense and expensive drilling. Using the examples of two different geothermal systems in Iceland that have been drilled for geothermal energy exploitation, COTHERM will pursue four interconnected sub-projects to advance our knowledge about these systems and to develop improved geochemical and geophysical techniques for monitoring and imaging of geothermal systems :
(1) Computer simulations to understand how strongly the water gets heated and how much hot water can flow through different rock types and in different geological settings.
(2) Computer-aided modeling of how fast the hot water can dissolve minerals from the rock and precipitate others, which may influence or even block the pathways of the hot water.
(3) Use the rock properties, flow paths and temperature distribution predictions from the above two sub-projects to simulate how geophysical methods could be used to probe the underground system structure without drilling.
(4) Collect geochemical, mineralogical, and geophysical data at the two systems in Iceland to compare the simulation results of sub-projects 1 to 3 with actual data in order to refine, validate, and integrate these different approaches.