Physical simulation experiments of remaining oil distribution and production in alluvial fans controlled by dynamic and static factors

Abstract In order to study the remaining oil distribution and production in alluvial fans controlled by both static geologic factors and dynamic development factors, 2D and 3D macroscopic physical models have been constructed for the alluvial fan reservoirs in the eastern part of Cangdong sag, Bohai Bay Basin, China. Through considering static reservoir architecture and dynamic displacement rate, perforation position, well type, and well pattern, 7 water flooding physical simulation experiments have been finished, and the remaining oil distribution and production in oilfields with ultra-high water cut controlled by both dynamic and static factors were revealed. The study shows that without considering the economic benefits, drilling horizontal well, drilling infilled vertical well, increasing displacement rate, and plugging off water flooded layers at the initial stage of ultra-high water cut exhibited decreased performance in remaining oil production. After the dynamic factors adjustment, the remaining oil distribution and production is mainly controlled by the interlayer position, reservoir rhythm and the combination relationship between dynamic and static factors. When more injector-producer groups are located in the same single sand body, and the oil wells are uniformly drilled in single sand of different types, the oil recovery efficiency will be higher, and the distribution of the remaining oil will be more uniform. According to the experimental results, the remaining oil controlled by braided sand island and braided river channel could be divided into three types, and the corresponding measures to tap the potential were proposed.