The interest in aquifer heat storage and the use of hydrothermal deposits in the subsurface is growing steadily. However, the associated risk of discovery still prevents investors from developing the technologies commercially.
The “GeoFern” project is now intended to reduce the said discovery risk and at the same time provide the design parameters for efficient system integration with safe operation in the Berlin district heating supply.
With the help of drilling and innovative exploration methods, such as passive seismic measurements, the GFZ hopes to gain a more detailed understanding of the deeper subsurface near Berlin in order to make statements about the storage capacity and capacity. In addition, processes and reactions in the subsurface must be recognized and modeled using geophysical, hydrogeological, geochemical and drilling methods.
A vertically sunk exploratory borehole to a depth of around 650 m is currently planned. At the same time, around 250 m of core drilling is to be carried out for further scientific investigations using a so-called rope core drilling process. The target horizons are Jurassic and Triassic rock formations.
The exact work packages are on the website visible at the GFZ.
In addition to the knowledge gained from the exploratory drilling, energy-related aspects, field and laboratory tests, as well as extensive test, measurement and sampling programs are also taken into account.
The project duration began in July 2019 and is initially limited to June 2022. Appropriate preparatory measures, such as the analysis of the subsoil conditions or the construction of the drilling site (setting of the standpipe, construction of the borehole), have been carried out since August of this year. The necessary permits with regard to the exploration permit and the main operating plan were obtained from the applicant between September 2019 and August 2021.
The project team includes local actors from science, politics and business, which can significantly reduce licensing and administrative delays. In addition to the project management of the GFZ at the Helmholtz Center Potsdam, the BTB are also involved as project partners. The grant for the project is based on a resolution of the German Bundestag and is made by the Federal Ministry for Economic Affairs and Energy.