Monitoring the CO2enhanced oil recovery process at the nanoscale: an in situ neutron scattering study

Abstract

The CO2 Enhanced Oil Recovery (CO2-EOR) process was monitored in real time at the nanoscale by neutron scattering. This was achieved by in situ injection of supercritical CO2 into a limestone sample loaded with deuterated n-decane. The experimental results show directly the decane displacement upon supercritical CO2 injection. The structure of CO2 confined in the pores has also been evaluated and compared to that in the bulk state. Finally, analysis of the neutron results shows that small mesopores have low accessibility to CO2 suggesting that they will not be available for storage for geologic CO2 sequestration.