Fully-implicit solvers for coupled poromechanics of fractured reservoirs

In this work we present a family of preconditioners for accelerating the fully-implicit solution of linear systems encountered in two practical applications: (i) Lagrange multiplier-based fault mechanics simulations using a mixed finite element approach, and (ii) multiphase poromechanics based on a mixed finite element-finite volume formulation. We consider block preconditioning strategies and focus on various Schur complement approximations that are based on a combination of physical and algebraic arguments. The performance of the proposed framework is illustrated using two challenging numerical examples---a synthetic fault mechanics test with manufactured solution and a large-scale water flooding problem.