Modeling and comparing minimum miscibility pressure using multiple mixing cells for injection of enriched gases with Naphta, LPG, and NGL

The increase in oil production from hydrocarbon reservoirs has always been of interest due to the increase in global oil consumption. One of the effective and useful methods for enhancing oil recovery from hydrocarbon reservoirs is gas injection. Injectable gas can be injected into two modes, miscible and immiscible. However, to inject more efficiently, different factors, including Minimum Miscibility Pressure (MMP) in the gas near-miscible injection mode, should be investigated and determined. In order to investigate the minimum miscible pressure, different laboratory and simulation methods have been prepared and developed. This method uses the theory of multiple mixing cells to simulate, calculate and compare the minimum miscible pressure in gas injection enriched with Naptha, LPG, and NGL. Also vaporizing and condensing process is also considered in the simulation. The constructed model is presented with a new algorithm. This modeling has been validated and compared with laboratory results. The results showed that dry gas enriched by Naphta due to having more intermediate compounds at lower pressure (16 MPa) is miscible. In addition, dry gas, due to very light compounds, needs higher pressures (20 MPa) than all enriched gases for miscibility. Therefore, Naptha can be a good option for injecting rich gas into oil reservoirs to enrich gas.