CRIEPI’s Fractured Rock Studies - Hydrogeological characterisation
Every hydrogeological characterisation phase in the C-FRS project began with the detailed geological mapping of the excavated borehole cores.
Geological mapping of excavated borehole core. Photo: comet.
Information from a number of geophysical and hydraulic experiments is combined and interpreted to provide a comprehensive picture of the geological features at depth and the local hydrogeological conditions.
Exemplary hydrogeologic characterisation of one C-FRS project borehole: a) optical image with interpretation, b) drill speed and c) hydraulic test results.
Similar data were acquired in all boreholes until the integrated structural model of the C-FRS site could be drawn.
Hydraulic connectivity between the boreholes was assessed from monitoring hydraulic pressures while drilling. Drilling into a hydraulically conductive feature caused sudden pressure drops in adjacent boreholes. These results in combination with those from hydraulic monopole testing led to the definition of two fracture zones FZ1 and FZ2 which were proposed as potential target fracture zones for CRIEPI’s demonstration experiments.
Boreholes and simplified structural model for the C-FRS site:
a) hydraulically tested fractures, b) 2 target fracture zones.
CRIEPI’s Fractured Rock Studies - C-FRS