MODELLING FLUID FLOW IN STRESS SENSITIVE PETROLEUM RESERVOIR CONSIDERING FAULT REACTIVATION PROBLEM

This paper presents the application, to a synthetic example, of a formulation im- plemented in a finite element code CODE_BRIGHT to simulate fluid flow in petroleum reser- voir sensitive to stress state. In this program the equations of fluid flow problem are solved together with the stress equilibrium equation, which characterize the geomechanical problem. It's a hydro-geomechanical coupling solved in a totally implicit manner, where changes in pressure field induce changes in stress state of rocks of the field, which can lead to reactiva- tion of sealed geological faults. The fault reactivation problem considers that shear (with dilatancy), tension or compression of filling material may cause changes in hydraulic proper- ties. The mechanical constitutive model adopted to represent the behavior of the filling mate- rial of the fault is an elastoplastic Mohr-Coulomb model that is able to reproduce the fault activation through reservoir and adjacent rocks (fluid and pressure propagation).