Pulse testing in Geothermal Energy: Demonstration of a new monitoring tool.

Harmonic pulse testing has been employed to identify the thermal front in a geothermal system and in a heat storage system. For the geothermal system we could identify the hydraulic reservoir properties around the well. Operational constraints in combination with the distance to the thermal front precluded its identification using this test. For the heat storage, however, we did identify the heat front. After a season of injection of hot water, the heat front had propagated into the reservoir to 100 m from the well. This was in line with the value calculated from a volume and heat balance on the basis of the amount of hot water injected, the height of the reservoir and the respective heat capacities.