Abstract: Ⅴ formation in Shuanghe oil field has already entered the late period of ultrahigh water cut,with water cut of up to 95.21%.Because of innerlayer and interlayer heterogeneity of reservoir,between layers there is big difference in production,and the main pay zones are severely flooded.In this paper,the main developing problems in V formation are analyzed,the distance between oil well and water well is big,wellpattern is not perfected,injected water is insufficiently used and injected water absorption profile is asymmetry.Distribution of the remaining oil is established according to oilwater well test and reservoir numerical simulation data.This research indicates that next adjustment direction is remaining oil accumulation area located in the side of formation,adjacent faults and the high remaining reserve regions.Some EOR technologies are put forward,including adjusting and perfecting wellpattern,blocking the larger reservoir pore space in order to adjust profile control,and developing tertiary recovery.After these technologies are used in practice,obvious effectiveness of increasing oil and decreasing water production is achieved,and the water flooding recovery is enhanced.A set of enhanced oil recovery technologies is formed,and it provides a referential evidence for improvement of development effectiveness in the period of ultrahigh water cut.

Key words: high water cut, remaining oil, EOR, potential recovering, effectiveness