Abstract: During the development of Lei 11 Lianhua reservoir, there exposed lots of questions.The reserve's geological condition is complex,the water- oil relation is difficult to understand, and the reserve exploring status of each layer is different.In recent years,the research on reservoir geology and the residual oil distribution law of the reserve have been deepend.Based on re - understanding of the structure,small layer division,study on the sedimentary fancies and the water detection after the second fine well log interpretation, and supplemented by separate layer water injection,subdivision injection,one to one injection and the auxiliary water injection technology,the fine reservoir potential tapping work has been carried on.This not only has reversed the decline trend of blocks' production,but also provides a good guide for other similar low permeability reservoirs' development.