Electromagnetic methods for exploration and monitoring of enhanced geothermal systems - A virtual experiment

To demonstrate the procedure and the capabilities of our method, we show the model preparation and the simulation results for the transient electromagnetic method in the context of a prospective enhanced deep geothermal energy site at the fault 'Roter Kamm' near Schneeberg in Saxony/eastern Germany. We show the changes in the measuring signal caused by the stimulated fracture system in more than 5000 m depth for a range of electrical resistivity contrasts, which represent different porosity, pore connectivity or fluid resistivity variations. When a borehole receiver is advantageously placed at depth, percentage changes in the measuring signal of 25% can be expected. Our study demonstrates, that the optimal positioning of source and receiver is crucial for a successful monitoring and may only be achieved with advanced simulation techniques.