Based on the true micromodels of sandstone

the twophase displacing process of oil by water of the Jurassic Y-9 and Y-10 oil reservoirs in Fanjiachuan-Yuancheng oilfields was observed.The results show that the displacing efficiency was in inverse proportion to the entering pressure and direct proportion to permeability.The displacing efficiency of Fanzhong area and Y-9～Y-2 substratum were the best among the three zones and the three substratums of Y-9 reservoirs respectively.The main factors that affecting the displacing efficiency are drive pressure

permeability

the microheterogeneity of pore structure and apparent porethroat volume ratio.