The oil deposit of Fuyu Oilfield is controlled by the structure.The reservoir with serious heterogeneity is medium porosity and medium-low permeability.At present, it has entered the late stage of high water development.For the development contradiction,to be better discovering remaining oil, a fine water-injection development test was carried out in the west X block. The west X block was divided into eastern and western parts and adopted different ways of putting it into production and betting.The various periodic water-injection methods were carried out.Each development index of the block has been improved and the stable output effect is good.Research shows that the encrypted water-injection wells have realized stratigraphic subdivision and increased the effect direction of the oil well plane.It improved the control degree of well pattern to single sand body,reduced inter-layer interference and improved the control degree and swept volume of water drive.The remaining oil is distributed scattered in the study area.In the longitudinal direction,it is mainly distributed in the main layer,and mainly focused on the top.The bottom layer is badly washed.Interlayer structure interface and thin argillaceous interlayer have shielding effect.It can effectively control the water absorption condition of the oil layer thereby control that distribution of longitudinally remaining oil.