Abstract: Many studies have been done about the mathematical model of layered reservoirs with crossflow. The dual permeability model proposed by D. Bourdet is the most practical one. But its application is limited because it is numerically unstable when the skin factor is negative. Based on the concept of effective wellbore radius, a new model of layered reservoir with crossflow is presented in this paper. The new model is numerically stable and takes into account the influence of wellbore phase redistribution and it enlarges the application range of Bourdet s model.

Key words: Percolation flow dynamics, Layered reservoirs, Wellbore phase redistribution, Crossflow, Bottom hole pressure, Effective wellbore radius, Mathematical model, Analytical solution