Technologies and practice of CO2 flooding and sequestration in China

Abstract

The latest advancement of CO2 flooding and sequestration theory and technology in China is systematically described, and the future development direction is put forward. Based on the geological characteristics of continental reservoirs, five theories and key technologies have been developed: (1) Enriched the understandings about the mass transfer characteristics of components between CO2 and crude oil in continental reservoirs, micro-flooding mechanism and sequestration mechanism of different geological bodies. (2) Established the design method of reservoir engineering parameters, injection-production control technology and development effect evaluation technology of CO2 flooding, etc. (3) Developed a series of production engineering technologies such as separated layer CO2 injection technology, high efficiency lifting technology, on-line wellbore corrosion monitoring and protection technology. (4) Innovated a series of surface engineering technology including CO2 capture technology, pipeline CO2 transportation, CO2 surface injection, and production gas circulation injection, etc. (5) Formed a series of supporting technologies including monitoring, and safety and environmental protection evaluation of CO2 flooding reservoir. On this basis, the technological development directions in the future have been put forward: (1) Breakthrough in low-cost CO2 capture technology to provide cheap CO2 gas source; (2) Improve the miscibility technology between CO2 and crude oil to enhance oil displacement efficiency; (3) Improve CO2 sweeping volume; (4) Develop more effective lifting tools and technologies; (5) Strengthen the research of basic theory and key technology of CO2 storage monitoring. CO2 flooding and sequestration in the Jilin Oilfield shows that this technology has broad application prospects in China. Key words: continental reservoirs, CO2 flooding and sequestration, enhanced oil recovery, reservoir engineering, injection and production engineering, surface engineering, development direction