Mathematical Model for Condensate Gas Flow in Porous Media with Phase Change

Abstract

The retrograde condensation occurs in the condensate gas reservoir when the formation pressure is under dew point. The condensate appears in the formation with phase change in the process of condensate gas flowing in porous media, which change the temperature field and distribution of fluid pressure and affect flow rules of condensate gas in porous media accordingly. New momentum equations are set up, considering Non-Darcy flow effects, the phase change between condensate gas and condensate, phase velocity and fluid character, based on a simple model of three zones. Surface tension and capillary pressure were introduced into the new model. At the same time energy equations are deduced considering latent heat of vaporization and fluid-solid heat coupling. A mathematical model of multiphase flow in porous media with phase change is set up in this paper combining new momentum equations, new equations of energy with equations of mass conservation.