2022-12-01
SPINE project experiments starting this week
In the framework of the SPINE project, a team of scientists is conducting hydrotests in the BedrettoLab. These experiments aim at applying the so-called SIMFIP (Step-Rate Injection Method for Fracture In-situ Properties) probe, a device for measuring the stress state in boreholes. The key idea of the SPINE project is that a single measurement of a displacement in the borehole wall can be used to determine the overall stress. Such a displacement occurs in the micrometer to nanometer range and is caused by the injection of water. Detailed knowledge of the state of stress in the subsurface contributes to estimating the seismic risk of a deep geothermal project.
During a period of two weeks, the international SPINE team runs about ten hydrotests for approximately four hours each. Hydrotesting is the term used to describe tests in which a small amount of water is deliberately directed into small fractures found naturally along the borehole. Since only small volumes of water will be injected, the occurrence of seismic events is not expected. Nevertheless, the routine safety protocols will be applied and the experiments would be put on halt if predefined magnitude thresholds are reached.
In these experiments the water flows through the SIMFIP probe which is then able to capture millimeter to nanometer displacements of fractures affecting the borehole. Being part of a test series carried out in various laboratories, these hydrotests at BedrettoLab are contributing to the development of the SIMPFIP technology within the SPINE project. 1 December 2022