Oil Recovery Potential From Fractured Reservoirs by Mass Transfer Processes

摘要

The purpose of this work is to evaluate the incremental oil recovery by evaporation and diffusion processes in fractured reservoirs and to provide a simple method for scale-up assessments. A macroscopic analysis of the flow and mass transfer phenomena in the porous matrix is performed on the basis of previously published experimental observations on core samples. This leads to analytical expressions for the evaporation, or, equivalently, drying rate, the extent of the two-phase zone in the matrix, and the location of the propagating front during both the steady and the falling rate periods of the process. Such expressions permit fast, albeit approximate, scaling considerations and recovery potential calculations. They also lead to conclusions concerning the optimal injection conditions and the desired injection gas properties.