This paper presents a numerical simulation study of the flow behavior within a vuggy fractured medium when oil is displaced by water. The experiments were conducted with an acrylic cell, where fractures were represented by channels of 2 mm wide, 1.7 mm depth and 16 cm long, whereas the vugs were represented by cylinders of 1 cm diameter and 1.7 mm depth. The experimental runs were carried out at different water injection rates between 2 and 200 ml/h and variable pressure between 0.006 and 0.910 psi.

The simulation runs, carried out using Eclipse 300 reservoir simulator, required to discretize the domain by using a rectangular grid with 2 mm square cells. Each cell in the vugs was divided into 3, 4 and 5 parts to approximate the vugs shape.

To simulate correctly the phenomena that occur in the experimental cell, it was necessary to try 3 different two-dimensional grids (up to12000 cells were used). It was also necessary to generate relative permeability curves and its corresponding capillary pressure curve.

Furthemore a method to calculate the capillary pressure is presented, both when the wetting or nonwetting relative permeability is available.

A good representation of the lab results was obtained through the simulation. This is relevant as an application of a reservoir simulator to study the dynamical behavior of fluids at this scale.

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