Author(s)

Yichun Wang, Xinyu Yao, Sen Wang, Qihong Feng

Corresponding Author

Qihong Feng

ABSTRACT

On one hand, the microscopic underlying mechanism of CO2 huff-n-puff process remains ambiguous. On the other hand, realistic shale organic matter should be simplified as a slit one. In this work, basic on grand canonical Monte Carlo (GCMC) simulations, we study competitive adsorption between CO2 and CH4 with pressures up to 30 MPa and then insight into recovery mechanisms during CO2 huff-n-puff processes in kerogen-based slit nanopores at 353K. With increasing pressure, the selectivity of carbon dioxide relative to methane decreases and tends to approach a constant. Enlarging the pore suppresses the selectivity of carbon dioxide over methane. We also discuss the process of CO2 huff-n-puff. This study provides the fundamental understanding of the recovery mechanisms in kerogen slit and sheds light on CO2 enhanced hydrocarbon recovery in shale gas reservoirs.

KEYWORDS

Shale gas, Adsorption, Kerogen, CO2 sequestration, Molecular simulation