Mechanistic investigation of bypassed-oil recovery during CO2 injection in matrix and fracture

N-octane diffusivity enhancement via carbon dioxide in silica slit-shaped nanopores – a molecular dynamics simulation

“…A common approach is coupling CO2 sequestration with enhanced oil recovery, in which CO2 can be used as an additive for tertiary oil recovery in depleted petroleum reservoirs. 1 It is desired that, once injected, CO2 displaces the hydrocarbons and undergoes mineralization to be permanently trapped within the rock formation. 2 Understanding the molecular phenomena related to adsorption and transport of CO2-hydrocarbon mixtures in the sub-surface is therefore necessary in order to optimize both CO2 storage capacity, as well as oil and gas production.…”

Effect of petrophysical matrix properties on bypassed oil recovery from a matrix-fracture system during CO2 near-miscible injection: Experimental investigation

“…All experiments were performed at the constant temperature of 80 °C. According to the previous studies on the decane-CO 2 system ( Cismondi et al, 2012;Khosravi et al, 2014 ), the critical pressure is equal to 14.24 MPa at 80 °C. Hence, our experiments were performed under three pressures of 15.86, 13.79 and 13.1 MPa, representing first-contact miscible, near-miscible and immiscible, Table 2 Basic properties of decane-CO 2 system ( Khosravi et al, 2014 respectively.…”

“…This promotes http ϕ porosity vaporization and eventually leads to higher oil recoveries. A number of previous experimental and simulation studies suggest that the near-miscible gas injection is more efficient than the firstcontact miscible gas ( Burger et al, 1994( Burger et al, , 1996Khosravi et al, 2014;Pande, 1992;Sohrabi et al, 20 08a, 20 08b;Thomas et al, 1994 ). Pande (1992) and Burger et al (1994) in their simulation studies showed that the highest recovery is yielded at pressures lower than the required MMP.…”

“…Although they achieved the highest oil recovery in the first-contact miscible injection, they showed that mass transfer is remarkably high in near-miscible injection on an experimental scale. Khosravi et al (2014) studied the importance of active forces in cross-flow from the bypassed zone to the flow zone in a matrix-fracture system. They concluded that the highest recovery is obtained in the near-miscible injection owing to the dominating mechanism of vaporization, which is enhanced in the near-miscible conditions as a result of the near-critical-point wetting phenomenon.…”

“…Experiments are defined in three cases of first-contact miscible (IFT = 0), near-miscible (IFT close to zero) and immiscible (IFT greater than zero). It is noteworthy that this classification is already used by other researchers ( Khosravi et al, 2014;Sohrabi et al, 2008aSohrabi et al, , 2008b. For better understanding of all simultaneous processes in the system, it is essentially important to characterize the phase behavior of the existing fluid system.…”