Approximation of Oil Production Well Index in Hydrocarbon Reservoirs Using Computational Fluid Dynamics

In the present work, the three dimensional fluid flow inside a hydrocarbon reservoir block along with the fluid flow inside the wellbore of a production well drilled in this reservoir block is numerically simulated. To do this, the single-phase incompressible fluid flow in the hydrocarbon reservoir in terms of Darcy’s law (porous media flow) along with the fluid flow inside the wellbore in terms of Navier-Stokes equations (free flow) are simultaneously solved. The effects of boundary conditions imposed on the faces of the reservoir block, the off-centered wellbore, and the reservoir rock permeability on the fluid flow behavior inside a reservoir block are investigated. In each case, the well index is numerically approximated, using the pressure and velocity distributions in the reservoir block and the wellbore pressure, and compared with analytical well index. The numerical results indicate that the well equivalent radius and also the well index not only depend on the geometrical properties of reservoir block and well bore and the rock absolute permeability, but also depend on the boundary conditions imposed on the reservoir block faces and the well drilling location.