As part of the GFK-Monitor project, a fiber optic cable was installed for the first time in an open-hole section of a deep geothermal borehole. The borehole and the subsoil are now being examined over a length of more than 4 km.

Our partner, the Munich municipal utilities, writes:

The GFK-Monitor project builds on research work within the framework of the Geothermal Alliance Bavaria, in which fiber optic temperature, pressure and acoustic data have been collected at the southern energy site since 2020. With the three fiber optic cables now installed, a holistic monitoring system is being created for the first time that has never existed in this form before. Fiber optic sensors at the end of the cables measure the pressure in and above the thermal water reservoir, and the temperature is also recorded around the clock across the entire depth. Acoustic data is also collected, which allows live monitoring of potential seismicity. Researchers are thus continuously supplied with measurement data from the depths.

The new thing about the cable in Th6: Here, the last section, around a thousand meters long, hangs loosely in the thermal water without piping. This allows its flow paths to be determined more precisely. The thermal water layer can also be modeled over a much wider area. This benefits the overarching goal of the GFK-Monitor project, which is to advance geothermal energy through a better understanding of the subsurface. More accurate modeling of the thermal water layer makes it possible to determine suitable locations for future drilling more quickly. Holistic monitoring of the depth also increases the production and operational reliability of geothermal plants. With the GFK-Monitor project, SWM is supporting and accelerating the further expansion of deep geothermal energy in Munich.

Here you can find more information about the GFK-Monitor and the Munich municipal utilities (project information only available in German).