In the later development stage of strong bottom water sandstone reservoir of Tahe Oilfield

the development effect of remaining oil between wells is poor

and the conventional EOR methods is inapplicable. In order to solve these problems

the feasibility of CO

2

flooding in this type of reservoir has been explored. By combining laboratory experiments

numerical simulation and conventional reservoir engineering

the CO

2

flooding mechanism for sandstone reservoir with strong bottom water has been studied

and the MMP of CO

2

used in Tahe sandstone reservoir with strong bottom water is determined to be 29.6 MPa

the main mechanism of CO

2

flooding is preliminarily d

efined to be such as swelling of oil and expansion of horizontal swept area

the dissolution and distribution ratio of CO

2

in oil and water is about 4:1

and the CO

2

flooding can increase the recovery by 12.5 %. All these show that CO

2

flooding in Tahe sandstone reservoir with strong bottom water is feasible. The research results lay a theoretical foundation for EOR technology of this kind of reservoir and provide a scientific basis for CO

2

flooding pilot test of Tahe bottom water sandstone reservoir.