EVALUATION OF METHODS TO LOWER MMP OF CRUDE OIL IN GAS MISCIBLE DISPLACEMENT

As the crude oil production declining over the years, various efforts have undertaken to increase the oil recovery through implementation of EOR projects. Among several methods of EOR, gas injections were found to be the most favourable process. In this project, CO2 miscible flooding is chosen for its volumetric sweep efficiency and lower minimum miscibility pressure (MMP). In the miscible displacement, minimum miscibility pressure is a key parameter to achieve miscibility between gas and oil. The key problem in this project is the initial reservoir pressure for Malaysia oil field is too low to achieve miscible displacement and thus it not recommended to implement CO2 miscible flooding. Therefore, this project will focus on studying the potential methods to reduce minimum miscibility pressure to ensure miscible displacement can be achieved in Malaysia oil field. In this study, the effects of injected gas composition on Dulang’s crude oil are investigated through 1D Slim Tube simulation by ECLIPSE 300 reservoir simulator. Impure CO2 gas streams and synthetic gas streams are investigated in this project. Studies has found that the addition of H2S, C2, C3, C4 and C5 hydrocarbon components can lower the CO2 minimum miscibility pressure (MMP) of crude oil. On the other hand, 16 synthetic gas samples were simulated and evaluated and the best synthetic gas sample will be selected. Gas 15 has provided lowest MMP which is around 1617 psia.