Thermo-hydro-mechanical effects of a well leakage near the Geothermal Power Plant of Landau, Germany

Significant surface vertical displacements, with a maximum of 5 cm, were observed near the Geothermal Power Plant of Landau, Germany, between 2013 and 2014. These vertical movements are associated with a leakage in the casing of the reinjection well at depths between 479 m and 751 m, corresponding to an uncemented section of the well. The leakage resulted from an injection of hot water into the subsurface, inducing coupled thermo-hydro-mechanical (THM) processes and ground surface uplift. While the contribution of hydraulic effects has been investigated in similar cases, the role of the thermal effects has been less explored. We have studied the Landau case by developing a new analytical solution to estimate ground surface vertical displacements that accounts for the effects of both hydraulic head and temperature changes. We have verified this solution with THM numerical models and real data measurements (levelling and PS-INSAR).

This work was financed by the ERANET project HEATSTORE (170153-4401). This project has been subsidized through the ERANET cofund GEOTHERMICA (Project n. 731117), from the European Commission, RVO (the Netherlands), DETEC (Switzerland), FZJ-PTJ (Germany), ADEME (France), EUDP (Denmark), Rannis (Iceland), VEA (Belgium), FRCT (Portugal), and MINECO (Spain). Also, the first author is supported by a grant from the Department of Research and Universities of the Generalitat de Catalunya (2023 FI-3 00208). S.D.S. acknowledges the support of the ‘Ramón y Cajal’ fellowship (reference RYC2021-032780-I) funded by MICIU /AEI /10.13039/501100011033 and by "European Union Next Generation EU/PRTR", and that from the HydroPoreII project (reference PID2022-137652NB-C44) funded by MICIU /AEI/ 10.13039/501100011033 and by “ERDF, EU”.