Characterization of non-Darcy multiphase flow in petroleum bearing formation. Final report

Abstract

The productive capacity of oil and gas bearing rocks depends on various parameters characterizing the flow conditions in the reservoir. Among these, the non-Darcy flow coefficient specifically plays an important role for cases involving fluid accelerations or decelerations around the well bore and in the reservoir. However, most reservoir simulators used for reservoir management assume Darcy flow, and yield misleading results causing an incorrect analysis or projection of reservoir performance. A few attempts have been made to incorporate non-Darcy effect in reservoir models but many of these lack a reliable accuracy since they use simplified correlations which ignore the effects of the variation of the fluid and formation conditions. The present study developed an accurate non-Darcy flow model that will lead to more accurate reservoir management decisions. First, a rigorous analysis and derivation of the porous media mass and momentum equations are presented considering the non-Darcy flow behavior. Second, steady-state and unsteady-state methods for simultaneous determination of relative permeability, capillary pressure, and interfacial drag during non-Darcy flow in laboratory cores are derived. This work results in several algebraic, integral, and differential interpretation methods. Third, correlations for the non-Darcy flow coefficient are investigated and improved. The study presented in this reportmore » provides new insights and formulations in the description of non-Darcy flow in oil and gas bearing formations.« less