Hydraulic modeling of induced and propagated fractures: Analysis of flow and pressure data from hydromechanical experiments in the COSC‐1 deep borehole in crystalline rock near Åre, Sweden

To characterize the coupled hydromechanical behavior of rock fractures, step-rate injection method for fracture in-situ properties (SIMFIP) was conducted with a specialized downhole probe developed by Guglielmi et al. (2014, https://doi.org/10.1007/s00603-013-0517-1). In June 2019, field campaign carried out near Åre, Sweden, where SIMFIP applied in Collisional Orogeny Scandinavian Caledonides-1 scientific borehole to understand dynamics injection-induced initiation, opening, and shearing due water injection-withdrawal interval isolated two packers. Three intervals were investigated at ∼500 m depth: (a) an unfractured section (intact rock), (b) non-conductive (c) hydraulically conductive fractures. Pressure, flow rate, wall displacement simultaneously measured during tests. present study, geometry induced deformation existing fractures different time stages tests are determined based on hydrologic model using pressure data each stage experiment. A numerical fluid within packed-off is implemented COMSOL Multiphysics. By matching simulations observed all three sections, estimates propagated fractures' radius aperture successive have been obtained case. We could also determine non-linear relationship between values above opening pressures. The results provide insights understanding pressure-induced initiation propagation crystalline rock.