Abstract: To the common water flooding oilfields, it is commonly seen that most of the oilfields face the problem that the water flooding effect gets poorer due to the higher ratio of wateroil viscosity when the oil fields reach the midlate development stages. In the paper, Haiwaihe Oilfield is taken as an example for the research. In view of the existing such problems in the oilfield as complicated geological conditions, low recognition degree of the oilfield, incomplete injectionproduction system, low producing degree by the water flooding, centered on 'injecting enough and good quality water ',the accurate geological and residual oil distribution regulation research are carried out. As a result, the water flooding effect has been greatly improved by appropriate measures, including perfecting injectionproduction well pattern, subdividing the water flooding unit, draining liquid, controlling the ineffective water cycling, controlling sand production and preventing casing destroy.

Key words: heavy oilfield, waterflooding, development results, injecting and producing frame, reservoir, midlate stage