Lab and Field Scale Modeling of Near Miscible Co2 Injection in Different Porous Mediums

The main purpose of this investigation is to study the effect of near miscible co2 injection indifferent porous mediums on both lab and field scales. this effect can be traced by the change oftwo-phase gas-oil relative permeability curves. in this work, the experiments have been performedon three rock types (i.e. sandstone, dolomite, and artificial fractured sandstone) based on anincremental pressure algorithm approaching a near miscible condition. lab-scale inverse modelinghas been used to calculate relative permeability curves. based on the experimental results, 85%ofminimum miscibility pressure was defined as the near miscible pressure. comprising the relativepermeability curves in immiscible and near-miscible conditions, the results show that this changehas become less significant from sandstone core type to artificial fractured. in other words, nearmiscible co2 injection would be recommended in rock types with a lower rqi. in addition, it wasconcluded that in the case of artificial fractured, simple conventional relative permeability methodsobtain the same results as sophisticated inverse modeling method. furthermore, in order tovalidate the lab scale results, the field scale modeling of the candidate reservoir was done using the3d compositional reservoir simulator. 83% of minimum miscibility pressure was defined as nearmiscible pressure. moreover, the simulation results confirmed lab-scale data regarding therecovery factor in different rock types. additionally, the economic evaluation (npv analysis)showed that use of near miscible co2 injection in lower rqi reservoirs was more economical ratherthan the other scenarios.