An Experimental Technique for Measuring Minimum Miscibility Pressure
Miscible gas injection processes can be applied to a huge number of mature reservoirs to improve the trapped oil displacement. An accurate estimation of the minimum miscibility pressure (MMP) is essential to make these injection schemes feasible and effective. Several methods have been reported in literature for MMP determination but slim tube and vanishing interfacial tension (VIT) are the deployed experimental techniques. Using VIT approach, pendent drops of oil were introduced in CO2 vicinity at sequence of pressures and constant reservoir temperature with subsequently measuring the interfacial tensions using axisymmetric drop shape analysis (ADSA) technique. MMP was determined through extrapolation of plot drawn between IFT versus pressure to zero IFT. Multiple contacts mixing cell based numerical approach was utilized to simulate the slim tube experiments. VIT technique measured MMPs were found in close match with slim tube determined MMPs for different crude oil – CO2 systems. Simulation software predicted MMPs matched the experimental determined MMPs in an acceptable limit. This study reveals the VIT technique as a reliable, economic and less time consuming method for MMP determination in comparison to slim tube technique.