Alcohol as an additive to increase CO2 and crude oil miscibility

This paper describes using alcohol as a solvent to reduce minimum miscibility pressure (MMP) during CO2 flooding for enhanced oil recovery (EOR). The problem with miscible displacement using CO2 is not feasible for high temperature and impossible for waxy reservoir. Gas is also more mobile than liquid inside the reservoir, in order to have higher recovery we must attain piston like displacement or miscible displacement, miscible displacement can attain recovery of 80% from the reservoir. Other methods are needed to form a miscible zone ahead of the injected CO2 such as using alcohol. The objective of this paper is to solve the problem by using alcohol to reduce minimum miscibility pressure between CO2 and crude oil. In this research, we use benzyl alcohol, branch alcohol and normal alcohol. Although, alcohol is often used as a co-surfactant and only a small amount is needed, alcohol can be used as the main IFT reducing agent if it can be produced cheaply. Y. Wu[1] and Qunsheng Li[16] had proven branched alcohol propoxylate sulfate and ethanol very effectively reduce interfacial tension. Qunsheng LI [16] also said that alcohol is a perfect surfactant because it soluble inside polar and non polar liquid, alcohol enhances the solvating power and polarity of carbon dioxide into crude oil. In this paper an attempt had been made using four types of alcohol that is phenol, 2-methyl-2-butanol, 2-methyl-1-butanol and 2-butanol, then it will be tested with Dulang crude oil at 60 C to see the effect of branching, cyclic and straight chain alcohol on solubility of CO2 into crude oil.