Moment-Frequency distribution as a constraint for hydro-mechanical modelling in fracture networks

Abstract

International audienceShear re-activation of deep fractured rocks for EGS purposes is accompanied by microseismicity. From our numerical hydro-mechanical coupling in discrete fracture network models which incorporates stress drops with known amplitudes and neglects the influence of static stress changes, it happens that the moments of induced seismic events are scaling with the power 3 of the fracture size. It follows that the value of the slope of the moment-frequency diagram better known as the b'value obtained from numerical experiments correlates with the exponent of the power law distribution used for the fracture size generation. Our suggestion is therefore to use these diagrams for constraining the fracture network generation proces