Structural dominated geothermal reservoir reaction during proppant emplacement in Geretsried, Bavaria

As a source of sustainable, renewable, and clean energy, deep geothermal systems increasingly gain importance for the energy transition. In Germany, the North Alpine Foreland Basin is the success story for hydrothermal systems. Besides successful projects in the Munich area, recent attempts to establish successfully operating geothermal wells southwards, e.g., in Geretsried, failed due to a lack of permeability of the rock mass. Subsequent research in Geretsried found that all existing discontinuities are low to non‐productive. The current project ZoKrateS, rethinking the Geretsried reservoir being a petrothermal play, bypasses these limitations by stimulating the existing fractures, and trying to keep them conductive by embedding proppants that prevent full closure. Four detached sections of the well GEN‐1ST‐A1 were subject to individual stages of stimulation. These four sections have been stimulated by placing proppants at injection pressures below the in‐situ least principal stress at no microseismic activity. After injection the communication between well and formation appeared to be increased. Although data processing is still ongoing, linear correlations between cumulative injected volume and quasi‐static pressure may be interpreted as channel flow within highly disturbed rock masses at intersections of faults. The high elasticity of these sections enables even low pressure to cause discontinuity opening below the least principal stress.