Abstract: Thick oil reservoirs are highly developed in Shuangheoilfield. At current high water-cut stage, residual oildistribution in these thick reservoirs are mainly controlledby the completeness of well patterns, formation verticalpermeability, depositional features of sand bodies,micro -structure and regional formation pressure. Residualoil enrich in well blocks with incomplete well patterns, informations with medium to low vertical permeability, inregions between distributury channels or at terminals ofdistributary channels where injection- production are poor,at micro-structural highs and in local injection pressurebalanced areas. Effective ways to tap production potentialsof thick layers in Shuanghe oilfield are optimizinginjection - production structure and injection waterallotment in addition to completing well patterns.