A prediction model of water flooding efficiency for layered thick reservoir

The thick oil reservoir usually featured with strong heterogeneity, thick oil layer and large difference in reservoir physical properties.Water flooding production of thick reservoir will be affected by heterogeneity, resulting in water cut rising rapidly and lowering oil recovery etc.So, prediction of water flooding efficiency is the key to develop the thick reservoir.Considering the fluid channeling and heterogeneity and introducing pseudo relative permeability function, and combined with Weldge-Craig water flooding theory, a method for calculating water flooding efficiency in thick oil reservoir was established.The reliability and practicability of the model were verified by the case calculation at site.Sensitivity analysis indicated that the larger the permeability variation coefficient and mobility ratio, the lower the crude oil displacement efficiency, which causes the poor development effect by water flooding.As for the water flooding development of layered thick reservoir, it is necessary to strengthen the understanding of reservoir heterogeneity vertically, perfect the injection and production well pattern, and increase the displacement efficiency, so as to improve water flooding recovery ratio of thick reservoir.