The geological conditions of fault block reservoirs are complex

whose small faults are developed

and reservoir heterogeneity is serious. When the reservoir enters the development stage with ultra-high water cut

the remaining oil is highly dispersed

the streamline between injection and production wells is fixed

the benefit of water drive becomes worse

and the spread of water flooding is difficult to further expand. Streamline adjustment and development have become the main direction of cost reduction and efficiency enhancement for fault block reservoirs when the price of oil is low. Conventional dynamic analysis is not suitable for the adjustment of high water cut fault block reservoirs. In this paper

streamline simulation method is used to analyze the influence of each factor on the streamline of water flooding

and grey relational method is used to calculate the influence degree of each factor. It is found that vertically heterogeneity

areal heterogeneity and injection-production well pattern have significant influences on streamline

while injection-production well spacing and injection-production pressure difference have relatively small influences. The streamline distribution model is divided into three categories: dense area

sparse area and blank area

on this basis

the optimal adjustment technology is formed. In several fault block reservoirs in Subei Basin

the adjustments of vector allocation

adding new waterline

reducing the number of wells in the well pattern

and reorganization after subdivision have been carried out. Remarkable effect of increasing oil production and efficiency has been achieved. It has certain guiding significance for the adjustment of the same type of reservoirs.