Reduction of the minimum miscibility pressure of crude oil-gas systems using various chemicals and its analysis on a lab-on-chip system

Gas injection is a common method to increase the oil recovery in crude oil reservoirs. In this method, when the pressure is above Minimum Miscibility Pressure (MMP), miscible gas injection occurs and oil recoveries increase drastically. However, MMP could be high due to the reasons such as heavy oil and high reservoir temperature. Through chemical-assisted gas injection applications, MMP values could be reduced and more efficient process could be achieved. In this study, alcohol and hydrocarbon based chemical agents such as methanol, ethanol, 2-butanol, cyclohexane, n-hexane, diethyl ether and acetone are used to decrease MMP. Vanishing Interfacial Tension (VIT) technique is used to determine MMP values of 3 different Southeast Anatolia region crude oils under varions chemical concentrations and temperature conditions and a new correlation is developed as a function of temperature and API gravity. PVT analyses and then coreflooding experiments, at which reservoir rock and water are used, are conducted by using determined chemical and concentrations. These analyses show that methanol addition prior to CO2 injection both increases the gas solubility in the crude oil and upgrades the last product quality. In addition, it is proven that methanol has the property to reduce the potential of asphaltene deposition. Studies on the lab-on-chip show that methanol can progress in the reservoir and consequently, the effect on the crude oil can advance to long distances.