Modeling downhole natural separation

This work presents three approaches for determining down hole natural separation efficiency.; The first approach is based on a one-cell simplified model that uses macroscopic versions of the drift flux two-phase flow model equations. Closure of the model is obtained through gas-liquid slip correlations for both the vertical and radial directions. The vertical closure equation is a well-known relationship used for vertical flow in pipes. The radial slip correlation is obtained based on available experimental data.; This second approach is based on a mechanistic model for the liquid flow field. A certain geometry for the liquid streamlines is assumed and the liquid velocities and pressure field is determined. Extension to two-phase flow conditions is obtained by tracking the trajectories of individual gas bubbles into this flow domain. Closure equations for bubble characteristic sizes were obtained based on available experimental data.; The third approach is based on a new technique for solving the two-dimensional governing equations of the two-phase drift flux model. Closure equations for the interface characteristic length are obtained based on the available experimental data.