Mohammad Ali Karambeigi - Petroleum Research Center, Petroleum University of Technology, Tehran, Iran
Riyaz Kharrat

Asphaltene precipitation due to EOR methods or natural depletion is a serious technical problem at petroleum industry. This paper presents the result ofasphaltene precipitation during associated gas injection, CO2 injection and natural depletion in reservoir condition. In addition, the effect ofvariations in operation pressure, injection gasconcentration and production rate on asphaltene precipitation and difference between slope of precipitation graph due to various method of EOR ornatural depletion were investigated. The results revealed that temperature has an efficient role onresult of asphaltene deposition through associated gas and CO2 injection. By decreasing temperature, the amount of asphaltene precipitation due to associatedgas injection was increased. In fact, recovery of gas injection was decreased at lower temperatures, hence;solubility has an important rule on asphaltene precipitation.