Miscible gas injection is one of the effective techniques to enhance oil recovery and efficiency of this process is dependent considerably on the determination of Minimum Miscibility Pressure (MMP). Finding the value of MMP at operational condition has been always challenging. Various methods such as experimental methods, empirical correlations, numerical and analytical modeling are developed to measure or estimate MMP. Measurement of MMP using Slim tube test is a standard and acceptable industrial technique, however, it is time consuming, costly and fairly complicated. Vanishing Interfacial Tension (VIT) technique can be employed instead to measure the interfacial tension in various pressure ranges and using the extrapolation techniques towards zero IFT, the minimum miscibility pressure can be estimated. The results from VIT test is in good accordance with other miscibility measurement tests and two key parameters of IFT and MMP are determined, effectively. In this project, the MMP of a light crude oil sample from one of Iranian carbonate reservoirs were obtained in contact with CO₂ and N₂. The obtained results from the compositional modeling of slim tube test, VIT technique, numerical and analytical modeling and empirical equations were compared and analyzed.

Findings

Determination of minimum miscibility pressure in oil-gas system using slim tube test and VIT technique

Determination of IFT and density of phases