Applications of hydro-mechanically coupled 3D mine and reservoir scale, discontinuous, strain-softening dilatant models with damage

Flatten, A., Beck, D.
Copyright 2015 ARMA, American Rock Mechanics Association

In gas and oil as well as in several mining applications hydro-mechanical phenomena play an important role and need to be considered in numerical models for calibration and forecasting analyses. In this paper, a two-way coupled hydromechanical formulation is described and applied to real size, complex 3D mining and reservoir model examples including structures using the Finite-Element Method (FEM) framework. The proposed coupling considers increasing hydraulic conductivities due to the evolution of rock mass damage induced by mining activities or fluid injection. This enables the potential development of additional flow paths and affects the fluid pressure distribution, which, in turn, affects the mechanical response via the effective stress concept. The mechanical framework uses a strain-softening, dilatant and discontinuum constitutive model for both bulk rockmass and structures such as faults on a regional scale and discrete fracture networks (DFN).