Abstract
An improved commingled well production model is presented by coupling of hydraulics of various reservoirs zones with wellbore in multilayer reservoirs considering different wellbore and formation cross-flow and external boundary effects, including water-influx. The pressure and production of each layer is described by the leaky-tank model of Civan (2000) under prescribed cross-flow and boundary effects. The pressure and flow along the wellbore is determined by means of the Cullender-Smith (1956) model. A Newton-Raphson iterative finite-difference numerical solution is obtained for the strongly-coupled model for accurate analysis of the optimal production, injection, and shut-in conditions at the surface for reservoir systems containing more than one layer. Application of the proposed model is demonstrated by simulating and analyzing a reservoir containing three producing layers, each having different effective thickness, permeability, skin factor, and initial reservoir pressure. The robust commingled reservoir production simulator presented in this paper may be instrumental for prediction of the prevailing fluid flow and pressure profiles along the wellbore and various reservoir layers.
