Computational modeling of formation and evolution of damage zones in reservoir scale

Resumo

Geological fault zones can act as barriers or conducts for oil and gas flow in petroleum reservoirs. Fault
zones are divided into two regions, the fault core and the adjacent damage zone. The core is the region that
concentrates the greatest displacement and in general acts as a barrier for fluid-flow. On the other hand, damage
zones are characterized by relatively less intense deformation and can exhibit geological structures such as
fractures and deformation bands. Such zones can impact not only the fluid-flow within the reservoir but also the
mechanical behavior. Thus, the characterization of the damage zones is crucial for better management of oil fields
during the production phase. In this study, we present numerical models based on the finite element method (FEM)
to study the structural evolution of the damage zones in reservoir scale. Sensitivity analyzes were performed
varying the mechanical properties of intact rocks in order to check their impact on the structural evolution of the
damage zone. The obtained results allowed the identification of key parameters for damage zone evolution and
highlighted some advantages of FEM for the analysis of this kind of process.