Carbon dioxide-enhanced oil recovery(CO_(2)-EOR)has gained widespread attention in light of the declining conventional oil reserves.Moreover,CO_(2)-EOR contributes to the reduction of the global emissions of greenhous...Carbon dioxide-enhanced oil recovery(CO_(2)-EOR)has gained widespread attention in light of the declining conventional oil reserves.Moreover,CO_(2)-EOR contributes to the reduction of the global emissions of greenhouse gases through CO_(2) sequestration in subsurface geologic formations.This method has been largely used in the petroleum industry for several decades especially for extracting oil from light-to-medium oil reservoirs approaching an advanced state of maturity.Traditionally,CO_(2) is used in a continuous flooding scheme for EOR.However,continuous CO_(2) flooding tends to be problematic due to unfavorable mobility,viscous fingering/channeling and early breakthrough of CO_(2),especially in the presence of reservoir heterogeneities.In this paper,recent developments in the methods used to overcome these problems are reviewed.These developments include CO_(2)water-alternating-gas(WAG)injection,polymer-assisted CO_(2) injection,surfactant-assisted CO_(2) mobility control(CO_(2)-foam injection),and nanoparticle-assisted CO_(2) flooding.Each method addresses,to an extent,one or more of the problems associated with conventional CO_(2) flooding.Furthermore,incorporating more than one method can provide better performance in terms of CO_(2) mobility control and oil recovery.In comparison with CO_(2)-WAG and CO_(2)-foam injection methods,the use of polymers and nanoparticles with CO_(2) flooding is relatively new.These two new methods were mostly investigated experimentally,at the laboratory level,and they still need further development prior to field implementation.展开更多
基金supported by the National Priorities Research Program grant NPRP11S-1210-170079 from Qatar Na-tional Research Fund.
文摘Carbon dioxide-enhanced oil recovery(CO_(2)-EOR)has gained widespread attention in light of the declining conventional oil reserves.Moreover,CO_(2)-EOR contributes to the reduction of the global emissions of greenhouse gases through CO_(2) sequestration in subsurface geologic formations.This method has been largely used in the petroleum industry for several decades especially for extracting oil from light-to-medium oil reservoirs approaching an advanced state of maturity.Traditionally,CO_(2) is used in a continuous flooding scheme for EOR.However,continuous CO_(2) flooding tends to be problematic due to unfavorable mobility,viscous fingering/channeling and early breakthrough of CO_(2),especially in the presence of reservoir heterogeneities.In this paper,recent developments in the methods used to overcome these problems are reviewed.These developments include CO_(2)water-alternating-gas(WAG)injection,polymer-assisted CO_(2) injection,surfactant-assisted CO_(2) mobility control(CO_(2)-foam injection),and nanoparticle-assisted CO_(2) flooding.Each method addresses,to an extent,one or more of the problems associated with conventional CO_(2) flooding.Furthermore,incorporating more than one method can provide better performance in terms of CO_(2) mobility control and oil recovery.In comparison with CO_(2)-WAG and CO_(2)-foam injection methods,the use of polymers and nanoparticles with CO_(2) flooding is relatively new.These two new methods were mostly investigated experimentally,at the laboratory level,and they still need further development prior to field implementation.