Abstract: Zhaowa oilfield belongs to fan delta sedimentary bodies of steep slope type nearby provenances and the reservoir heterogeneity is serious.At present,the oilfield has entered into development stage of high water cut and the underground residual oil distribution is more complex and hidden.As there is great difficulty in tapping the potential,effective methods should be adopted.The effective driving pressure difference between water injection wells and production wells should be established to promote the rational flow of remaining oil.Through reasonable and dynamic adjustment,the fluid circulation has been promoted,the water-flood sweep volume has been enlarged and the efficiency of water injection has been improved.And then the unit development situation has been improved obviously.