Multilevel incomplete factorization for non-linear FE problems in geomechanics

The geomechanical simulation of a faulted producing reservoir is a strongly non-linear problem due to the non-elastic behaviour of the depleted rocks and especially to the contact constraint prescribed on the fault surfaces. With penalty interface elements for the fault modeling the stiffness matrix may be severely ill-conditioned and the solution by the PreconditionedConjugate Gradient requires the development and the implementation of ad hoc preconditioners. The present communication investigates the performance of a multilevel incomplete factorization aimed at enhancing convergence and reducing the computational cost of a nonlinear geomechanical simulation