Since 2016, Ansai oilfield has carried out polymer microsphere profile control and flooding, which has experienced three stages: pilot test, expand the scale of the test and promotion of three stages. The regional stage decline can be reduced about 5%, the overall effect is obvious, but the adaptability and application effect under different reservoir conditions are quite different, For the study of polymer microspheres in multiple media under the condition of mechanism, a group of 60 different particle size of polymer microspheres in different media under the condition of displacement test was carried out. Through the combination of experimental data and field application, the mechanism of microsphere oil displacement (percolation mechanism, change of flow direction mechanis) and the matching relationship between microsphere particle size and reservoir microfractures and pore throat are systematically summarized,which provides a basis for the optimization of construction parameters in the later stage.

The plugging effect of micro crosslinked polymer microspheres was studied by using nucleopore membrane filtration experiment. The experimental results show that the salinity has a great effect on the plugging effect of SMGm microspheres. With the increasing of NaCl concentration, the plugging effect becomes better. Under the conditions of same pressure and microsphere concentration, the filtration time of SMGm microspheres is better than that of high pressure. The results show that the effect of concentration on the filtration time is complicated and there is no obvious regularity.