Research Info

Measuring the Minimum Miscibility Pressure (MMP) in gas injection processes is of great importance. Common methods for measuring the MMP of oil and gas include laboratory methods, modeling, and simulation. In laboratory methods, the traditional raising bubble and Vanishing Interfacial Tension (VIT) methods, as well as the slim tube method, are used, although other methods are also used. The raising bubble method provides the MMP of oil and gas in a bulk of oil or a bubble of gas, without considering the reservoir conditions which is porosity and permeability. The VIT method is also similar to the raising bubble method, in which a gas drop is released in a bulk of oil, and the minimum miscibility pressure is measured. This method can detect the effect of asphaltene precipitation at the oil-gas interface on changes in interfacial tension, which undoubtedly affects the MMP. However, this method does not consider the porous medium. Although the slim tube method considers the MMP in a porous medium, however, if asphaltene deposition occurs during gas injection, the entire porous medium is blocked, and the slim tube will lose. Therefore, there is no method available to measure both the MMP and asphaltene deposition in the porous medium simultaneously. One way to measure MMP is to use an Equation of States (EOS) and simulation. Among various EOS, the novel Perturbed Chain-Statistical Associating Fluid Theory (PC-SAFT) has the capability to accurately provide MMP in the bulk. This EOS also models asphaltene deposition well and will show the effect of asphaltene deposition on MMP. In this study, for the first time, we modified the PC-SAFT for critical pressure and temperature, which can consider the porous medium condition, such as porosity and permeability. In this study, the deposition of asphaltene is also factored in through a modified equation for the reservoir rock's porosity and permeability, and it will be able to simultaneously study the effect of the porous environ