Severe injection water breakthrough occurs in Bohai BZ oilfield which has strong reservoir heterogeneity. Based on the good viscoelasticity and blocking property of “dispersed phase”, performance evaluation of heterogeneous combination displacement system and pilot test are carried out. Aiming at the limited space in offshore oilfield platform, injection equipment and injection technology of online profile control and oil displacement are developed to solve the problem of large occupied area of conventional equipment. The results indicate that the heterogeneous system can effectively block fluid advantage channels, change flow direction, increase the sweep efficiency and finally improve water flooding effectiveness. The success of online profile control oil displacement pilot test in Bohai BZ oilfield is of great significance to the development of technologies for stabilizing oil production and controlling water production in offshore oilfields