For the success of the implement of chemical flooding in Daqing oilfield

the viscosity

molecule coil size and molecular configuration of polymer solution

polymer/surfactant compound system

strong base alkali-surfactant-polymer（ASP） system and weak base ASP system

and the permeability range of the shale core and its influencing factors were studied under the same condition. The results showed that under the same condition

the viscosity and molecule coil size were in a descending order as: polymer/surfactant dual system

polymer solution

weak base ASP system

and strong base ASP system. While for the core permeability limit

the order was: polymer/surfactant dual system

strong base ASP system

polymer solution

and weak base ASP system. The reason was the bigger the molecule coil size was

the higher the core permeability that the oil-displacement systems could get through and the greater the permeability limit would be. But the strong base ASP system could react with the minerals in the cores

which resulted in the blocking of the core pores and the increase of permeability limit. The viscosity and permeability range of four kinds of oil-displacement system decreased with the increase of the shear strength

but the shearing action led to the oriented arrangement of the polymer molecules

the change law of polymer molecules in the oil-displacement system after shearing action was unobvious.