Page 58 - Hybrid Enhanced Oil Recovery Using Smart Waterflooding

50 Hybrid Enhanced Oil Recovery using Smart Waterflooding

summation of chemical potential of the all aqueous direct functions of effective molar Gibbs free energy of
species (Eq. 3.66). In this mechanistic model, there solution. The linear relation is used to modify residual
are two approaches relating the modification of residual oil saturation by the effective molar Gibbs free energy,
oil saturation and oil relative permeability to the and the interpolation factor is a function of Gibbs free
effective molar Gibbs free energy of solution. The first energy of solution as shown in Eqs. (3.67) and (3.68).
approach of the mechanistic model incorporates the The linear correlation also applies to the calculation
relationship between the molar Gibbs free energy of of oil endpoint and oil Corey’s exponent as a function
solution and contact angle. It applies the relationship of the effective molar Gibbs free energy. This mecha-
to either of the previously proposed empirical or funda- nistic methodology is applied to the third coreflood
mental models correlating the contact angle to the of Yousef, Al-Saleh, et al. (2012) and fourth coreflood
modification of residual oil saturation and oil relative of Mohanty and Chandrasekhar (2013). It calculates
permeability. In the second approach, the residual oil the effective molar Gibbs free energy for both
saturation, oil endpoint, and oil Corey’s exponent are corefloods (Fig. 3.5). The value of the effective molar

FIG. 3.5 The calculated effective molar Gibbs free energy of coreflooding experiments using the mechanistic
model. (From Al-Shalabi, E. W., Sepehrnoori, K., & Pope, G. (2015). Mechanistic modeling of oil recovery due to
low salinity water injection in oil reservoirs. In: Paper presented at the SPE middle east oil & gas show and
conference, Manama, Bahrain, 8e11 March. https://doi.org/10.2118/172770-MS.)