Abstract: The remaining oil distribution regularity of complex small fault block reservoir in extra-high water-cut period is complicated,which can seriously affect the economic development effectively and bring great difficulty for reservoir exploration and development adjustment work in the next step.Through comprehensive study of oil wells in the process of drilling,oil test and production,dynamic analysis method and the conventional water flooded layer interpretation method have been used to analyze the remaining oil distribution,the results show the water flooding degree of main layers is relatively low,and the remaining oil is relatively enriched.On the plane,the remaining oil is mainly distributed in the reservoir structure parts,the angle of the fault oilbearing area,property change belt,the retention area within the edge water reservoir water path,the area of low degree of well pattern control,and area of imperfect injection-production system.The main controlling factors of the remaining oil distribution are structure,sedimentary microfacies,reservoir heterogeneity,the water path,large hole and physical property change,and the perfect degree of the injection-production well spacing.