Quantitative description of the high-capacity channels in unconsolidated sandstone reservoirs,into which water was injected to improve oil recovery,is a hot topic in the fi eld of reservoir development. This paper presents a novel approach to describing quantitatively the characteristics of connected macropores in unconsolidated sandstone reservoirs using in situ production data. Based on physical simulation for formation mechanisms of high capacity channels and interwell tracer test data,a mathematical model was established to describe high-capacity channels by grey correlation theory,glow mechanism of fluid in porous media and reservoir engineering,and a program was developed to describe quantitatively the channel characteristics. The predicted results were consistent with fi eld monitoring data(80%) ,so this model could be economically and effectively used to identify high-capacity channels. Quantitative description of the high-capacity channels in unconsolidated sandstone reservoirs, into which water was injected to improve oil recovery, is a hot topic in the fi eld of reservoir development. This paper presents a novel approach to describing quantitatively the characteristics of connected macropores in Based on physical simulation for formation mechanisms of high capacity channels and interwell tracer test data, a mathematical model was established to describe high-capacity channels by gray correlation theory, glow mechanism of fluid in porous media and reservoir engineering, and a program was developed to describe quantitatively the channel characteristics. The predicted results were consistent with fi eld monitoring data (80%), so this model could be economically and effectively used to identify high-capacity channels.