The Research on Evaluation of Areal Sweep Efficiency in Low Permeability Reservoir with Streamline Numerical Simulation Method

摘要

Since nature fracture develops in the low permeability reservoir, the anisotropy has a great impact on areal sweep efficiency of water flooding, however most of the current methods don't consider and describe the influence of anisotropy. This paper introduces the frontal water equisaturation interface, defines the concept of areal sweep efficiency and calculates the breakthrough areal sweep efficiency of geometric well pattern by using streamline simulation technique. Meanwhile, we compare and verify the calculating results with reservoir engineering method. Based on the waterflood frontal movement, we have mapped out the plates of areal sweep efficiency of various aeolotropies both in quadrate inverted nine-spot pattern and in rhombus inverted nine-spot pattern with fractured vertical well. The method and plates could provide a good reference for calculation and evaluation of areal sweep efficiency of the low permeability reservoir.