Mechanism of CO2 enhanced oil recovery in kerogen pores and CO2 sequestration in shale: A molecular dynamics simulation study

•We study the adsorption behaviors of hydrocarbon mixtures in kerogen pores including slit pore and matrix pores.•The evolutions of CO2 flooding are detail descibed by density and quantity distribution of C8H18/CO2 along the z-direction.•The interaction energy between kerogen, CO2 and oil are calculated respectively to explain the mechanism of CO2 flooding.•It is a challenge to recover oil from kerogen matrix pores due to the lower D of C8H18 and strong Ekerogen-oil.•The storage capacity of CO2 is computed to clearly show that there is great potential for CO2 storage in kerogen.