Aims

The project aims to better understand thermal stresses in geothermal plants in order to be able to take them into account in numerical simulations in a suitable manner and to use them for the safe operation of geothermal plants.

Background

To explain seismicity, especially in the late phase of hydrothermal projects, thermal (cooling) stress changes are used, which often assume critical values in models, even further away from the actual doublet. If the underlying models were applied to geothermal plants, seismicity would often be expected, which would prevent authorisation. Observations of systems operated over decades usually show a different behaviour (e.g. Paris Basin). This means that, depending on the boundary conditions, there must be processes in which thermal stresses can be relieved to a sufficient extent.

Research focus

To find out how thermal stresses evolve over time for the different phases of hydrothermal projects: A) drilling phase, B) test phase, C) operational phase and D) post-operational phase. The technical work objectives include the development and testing of the numerical implementation of alterations, the creation of a workflow and a best practice elaboration for the modelling of thermal stresses for hydrothermal geothermal projects. In summary, the project aims to gain a better quantitative understanding of thermally induced seismicity, to use this knowledge for safe operation (also as a stimulation method and for risk assessment) and to implement it in models (workflow) for the long-term behaviour of geothermal plants.