On the equivalent permeability of fractured porous media

Resumo

Fractured porous media are present in different geological formations, such as rock masses and oil
reservoirs. The proper modeling of these fractured systems is of high relevance to the permeability assessment and
production management of the reservoirs. The fracture networks present in these media have a significant
contribution to fluid flow, once they create preferential paths for fluid transport. This work discusses the influence
of the fracture geometry on the equivalent permeability of fractured porous media. A generalized dual
porosity/dual permeability (DPDP) model is adopted to incorporate the fracture sets implicitly into the porous
matrix. This formulation was implemented into an in-house multiphysics framework called GeMA. Due to the
ease to simulate fractured porous media using DPDP, the influence of several parameters such as fluid viscosity,
matrix permeability, and fracture opening, spacing and orientation, are simulated generating a large number of
models. For each model, the horizontal and vertical equivalent permeabilities were estimated by applying a
horizontal and vertical pressure gradient, respectively. The numerical results showed that the fracture geometric
characteristics have a significant influence on the equivalent permeability and the dual porosity/dual permeability
model is a powerful approach to represent the behavior of fractured porous media.