CO2 assisted steam flooding in late steam flooding in heavy oil reservoirs

XI Changfeng,QI Zongyao,ZHANG Yunjun,LIU Tong,SHEN Dehuang,MU Hetaer,DONG Hong,LI Xiuluan,JIANG Youwei,WANG Hongzhuang

Table 3 Effect of CO2-assisted steam flooding with perforation adjustment after steam flooding.

Displacement mode Oil recovery/ % Stage water cut/ % Steam injection pore volume multiple CO2 injection pore volume multiple Stage oil steam ratio Steam flooding 20.1 95.2 1.10 0 0.12 CO2-assisted steam flooding 61.0 75.1 1.62 0.66 0.32 Total 81.1 2.72 0.66 0.24