After forty-three years water flooding development, the reservoir in Xing6 area is in high water cut stage of development, the scatter distribution of remaining oil and the poor development on thin and poor oil layers are present problems. On the basis of elaborate reservoir geological description, and using the skills of comprehensive description of the remaining oil, we analyze the features of remaining oil, as well as all types of layers’washing condition and adjustable sandstone thickness after second infilling in Xing6 area.In response to the sand layers with effective thickness under 0.5 m, the third infilling stage is implemented. Under the“three combinations”policy of optimizing well distribution, and through the adjustment of the well pattern, injection producer distance, well density,water flooding system, etc., the perfect injection and production systems are achieved to fully produce the remaining oil. The good results have been achieved in Xing6 area, and formed the matching infilling techniques.