Abstract: The distribution of remaining oil is complicated due to reservoir heterogeneity in the middle and late stage of oilfield development. Based on well logs and analysis data of sealed coring, by using the flow units division method according to microscopic characterization parameters, the reservoir was sub-divided into three types of flow units. The remaining oil distribution in target area was evaluated and predicted further by integrating the oil field production behavior. The study shows that proximal retrograding fan-delta front deposits with fining grains upwards developed typically. The reservoirs sitting in the central part of the fan-delta are mainly Type I flow units, with plenty of advantage flow channels and high water flooding, while the reservoirs sitting in the northern and southern parts of the fan-delta, are mainly Type Ⅱ and Ⅲ flow units with low water flooding, where the remaining oil is rich as well. Therefore, the prospective areas in the late period of oil production locate in the northern and southern part of the fan-delta.