The Study Of Sedimentary Microfacies And Flow Units Of Low-permeability Reservoirs In Infilled Wells Blocks In East 16

At present, many Chinese reservoirs has entered into high water cut stage of oil production, especially Daqing Oil Field that has entered into extra-high water cut stage of oil production. Some difficulties including scattered spatial distribution of remaining oil, the potential tapping difficulties and how to tap the remaining oil are major problems to raise the oil recovery ratio. The thesis starts with intricate segregation and comparison of the block reservoir in East 16 and compartmentalizes the sedimentary time unit into a single sand body unit level. The thesis also sets up the stratigraphic framework to analyze subtly the sedimentary microfacies and single sand body, which finally is conducive to the study of reservoir vertical heterogeneity and surface heterogeneity.The study of flow units is a good way to research the reservoir heterogeneity. Flow unit refers to the reservoir with the same seepage ability which is different in diverse flow unit level. Thus, it can reflect the power of reservoir heterogeneity. Flow unit also influences the distribution of remaining oil. A-class flow unit has the strongest seepage ability, which makes it easy form high permeability channels with relative high flooding ability. However, the seepage ability of B,C-class flow units is relative lower than that of A-class flow unit. The problems such as fairly flooding ability and non-flooding can easily lead to maintaining oil enrichment region, which make it a reservoir with more potential exploring space. Therefore, the B,C-class flow units will the main targets for exploring the remaining oil in the future.