Abstract: Zaoyuan oilfield K2 Formation is low permeability complicated fault reservoir,which has entered the high water-cut development stage. Its geological complexity and low-permeability reservoir production characteristics determine its development more difficult. The remaining oil is highly dispersed; stable yield becomes more and more difficult. This paper discussed the adjustable basis of K2 formation inthe later period of development based on the rational injection and production well space,development dividing series and the remaining oil distribution etc al. The paper also proposed the technical method of improving water flooding efficiencyof complicated low permeability faulted block reservoir by applying complicated structure well,drilling infill well,expanding injected water sweep volume and increasing fluidproduction on time. Author hope this paper will provide late stage development adjustment strategy for such kind of reservoir with reference.