A new investigation on modeling of permeability reduction during CO2 flooding processes in sandstone oil reservoirs

Permeability reduction in oil reservoirs during primary oil recovery and using the enhanced oil recovery methods are complicated problem which most of the oil field in worlds has encountered. In this work, a modified model based on four phase black oil model (oil, water, gas, and asphaltene) was developed to account permeability reduction during CO2 flooding in cylindrical coordinates around a well in a reservoir. The developed model was verified using data given in literature. The existing models use only two material balance equations based on asphaltene and oil phases in the porous media sample. Subsequently, this model has been used for examining the effect of well production rate and the initial reservoir permeability on the asphaltene deposition behavior in a typical reservoir during CO2 injection process. The results show that the developed model is more accurate than those obtained from previous models and is in good agreement with the experimental data reported in literature. Also, the results of proposed model indicate that at a fixed permeability, with increase in the production rate, the amount of asphaltene deposits will increase. However, an increase in the reservoir permeability will decrease the deposition rate because of the existence of further channels for flow.