Data integration and model updating in a multi-stage stimulation in the Bedretto Lab, Switzerland

Abstract

A series of hydraulic stimulation treatments were performed in the Bedretto Underground Lab for Geosciences and Geoenergies (BULGG) between 2020 and 2021. The objective of this experiment was to prove that multi-stage stimulation is a suitable technology to improve the reservoir quality in granitic rocks. Classical hydraulic tests, mini-frac tests and shear stimulations were performed in different boreholes and at different intervals. Each one of these treatments yielded observations and data that allowed us to update the structural, hydraulic and geomechanics reservoir model and improve our understanding of the whole system.Data resulting from the stimulation of one specific interval have been analyzed and integrated to build a coherent scenario. The integration of structural, hydraulic and geomechanical data is done using a Monte Carlo simulation allowing us to take into consideration the uncertainty inherent to each parameter. The comparison between theoretical results from the MC simulation and interpretations carried out on the data allow us to gain insights on the processes acting during the carried-out stimulation treatments.