CO

2

injection for enhanced oil recovery（EOR） has gone though 4 stages of technical improvements in North Jiangsu Basin. During the current low oil price period

three challenges are exiting: the high cost of CO

2

flooding makes it difficult to realize benefit development

the minimum miscible pressure（MMP） is too high to enhance oil recovery substantially

and the heterogeneity is too strong for expanding CO

2

swept volume. Therefore

three main countermeasures is put forward. Firstly

the optimization of scheme is the key. By full advantage of the old wells to reduce investment for new wells

optimiz

ation of injection mode to reduce injection volume

use of current equipment to reduce recycling cost

and overall plan for the pipe network to reduce gas cost

the cost of CO

2

flooding is reduced

thus

the equilibrium oil price of 60 % of the CO

2

flooding project will be kept below ＄60/bbl. Secondly

screening and evaluation of additives to reduce MMP are carried out. Meanwhile

the miscible condition was improved and the recovery rate of CO

2

flooding was increased by the injection in advance to increase the formation pressure. Tiredly

the swept volume of CO

2

is improved by means of injection at the high parts

water alternating gas injection（WAG）

and profile modification to mitigate gas channeling. The research and practice offer reference and examples for the beneficial development of CO

2

flooding in similar reservoirs under low oil price.