Geomechanical damage evaluation of fractured carbonate rocks scenarios related to the Brazilian Pre-salt via finite element analysis

Resumo

The structural configuration of the Brazilian Pre-salt oil system took place in a Rift tectonic formation
environment. The presence of faults, joints, breccias, fractures, and microfractures makes the system complex.
Natural discontinuities impact reservoir fluid production because they may be a highly conductive primary flow
pathway in naturally fractured reservoirs. Several factors affect the pathway conductivity, such as the fracture's
state, size, stiffness, and geometry. Moreover, fluid-rock interaction also controls the reservoir fluid production
dynamics due to the hydro-mechanical effects. Our work analyzes the geomechanical behavior of fractures in
naturally fractured carbonate reservoirs. We apply finite elements methods (FEM), the embedded strong
discontinuities methodology, and Barton's constitutive model. The methodology discretizes coarser meshes in the
domain and shows the impact of the fracture aperture as a function of the normal fracture stiffness. The results
show that initial fracture normal stiffness directly impacts the fracture deformability during production, especially
near the wellbore.