Determination of Fracture Scale Limit in Numerical Simulations of Fractured Vuggy Reservoir

In fractured vuggy reservoirs, the fracture scales differ and the fracture distribution is uneven, so fractures with varying scales may require different simulation methods. It is highly important to determine the fracture aperture limits, which are used to determine the fracture scale. In this paper, a uniform coarse grid and local refined grid are used separately in numerical simulations. The results of the two simulation approaches are compared and analyzed, based on which the fracture scale limit is determined. It is considered that the limit is reached when the two simulation results become significantly different. Based on the simulation result, it is concluded that the aperture limit of a large fracture in the numerical simulation of a fractured vuggy reservoir varies with the permeability of pores.