CO

2

flooding is effective for enhancing the oil recovery in low permeability reservoir and reducing the greenhouse gas emissions. In order to solve the technical problems of difficult miscible phase

easy gas channelling and low sweep coefficient for CO

2

flooding in low permeability reservoir in Shengli Oilfield. By the combination of physical and numerical simulation

the development mechanism of the CO

2

injection miscible flooding long in advance is clarified

and the comprehensive techniques for extra low permeability reservoir is formed. After field application

the stimulation effect is obviou

s

the daily production of oil per well increase by 5 times. The principle and technical idea of reducing the miscibility pressure are put forward

and the system of reducing the miscible pressure system is developed

which can make the pressure decrease by up to 22 %. The challenge and countermeasure faced by scale application of CO

2

flooding in Shengli Oilfield are analyzed

and the development directions of CO

2

flooding are proposed

such as deepening the phase state theory of oil recovery enhanced by CO

2

flooding

developing CO

2

flooding technology with expanded sweep volume at low cost

developing incomplete CO

2

miscible flooding

and description and early warning of gas channeling. All these provide technical support for oil field to realize scale application of CO

2

flooding.