Flow regimes and relative permeabilities during-steady state two-phase flow in porous media

摘要

Steady state immiscible two-phase flow in porous media is of substantial interest to the oil industry. A parametric experimental study of steady-state two-phase flow in porous media was conducted, using a model pore network of the chamber-and-throat type, etched in glass. Optical observations were used to determine the flow regimes, and macroscopic measurements to determine the corresponding relative permeabilities and fractional flow values. A key conclusion is that the long-held hypothesis that the non-wetting fluid flows only through connected pathways, is not valid. As it turns out, in three of the four flow regimes that were observed and video recorded, the flow of the non-wetting fluid is solely due to disconnected bodies of fluid. These results imply that a fundamental reconsideration of fractional flow theory is warranted. A new theory is proposed that is based on the ganglion population balance equations in combination with a network simulator that is used to calculate the system factors as function of the system parameters. The new theory gives very good agreement with experimental results. 49 refs., 8 figs.