It is necessary to study the increase of extraction from oil reservoir considering that the life of oil reservoir has passed the middle of its life and is entering the second half. There are various methods to increase the recovery from oil reservoirs. One of the methods of extracting value from oil reservoirs is the gas base method. In gas-based forms, measuring the minimum miscible pressure (MMP) is very important because the minimum miscible pressure determines whether the gas injection is miscible, immiscible, or near-miscible. There are mechanisms in each of these three injection modes that are completely different. According to the specific conditions of the reservoir, each of the miscible, immiscible, and near-miscible methods should be determined. The determination of miscibility is determined using the quantity of MMP. MMP itself includes two definitions: first contact miscibility (FCM) and multiple contact miscibility (MCM). There are many laboratory and modeling methods to measure MMP. Laboratory methods sometimes face very high costs and cannot cover all the effective parameters of the reservoir. Modeling methods also have many limitations, one of the modeling methods that can be used to calculate MMP is the MMP calculation method using the equation of state (EOS). Various equations of state can calculate MMP, the most common is Peng-Robinson's equation of state, but this equation does not provide us with MMP in equilibrium conditions and porous medium. In a porous medium, the MMP differs from the bulk medium. Therefore, in this study, the porous medium is included in the equation of state. In other words, the equation of state in terms of the porous medium has been modified by changing the parameters of critical pressure and critical temperature, critical pressure and critical temperature of oil and gas have been modified in an equilibrium manner, and the equation of state. Considering the porous medium (reservoir permeability and porosity) can provide