Effect of diffusion on minimum miscible pressure (MMP) during CO2 miscible flood: Case study of Iranian oil fields

Miscible CO2 gas injection has become one of the most efficient displacement processes for light and medium oil reservoirs today. An important concept associated with the description of miscible gas injection processes is the minimum miscibility pressure (MMP). CO2 has an advantage of low MMP over other gases; therefore most field projects are being operated through CO2 miscible flooding mode. Laboratory measurements as well as modeling of gasoil miscibility conditions are essential for success of any gas injection improved oil recovery process in the field. In thisstudy a slim tube model is constructed and simulated to accurate determination of MMP during CO2 flood in Iranian reservoirs. Conventionally Mass transfer effect on MMP is ignored. In this work, effect of diffusion on MMP during CO2 miscible flood is investigated. Considering diffusion in the process of CO2 miscible flood results in lower MMP. This result is closer to experimental data. According to the results of this study, effect of diffusion on MMP should be considered during full field CO2 injection modeling.

Keywords:

CO2 flooding , CO2 EOR , MMP , Mass Transfer