m amini - Department of Chemical Engineering ,Semnan University,Iran Petroleum research center, Department of chemical engineering , Sahand University of Technology ,Iran
m Nasiri Zarandi - Department of Chemical Engineering ,Semnan University,Iran Petroleum research center, Department of chemical engineering , Sahand University of Technology ,Iran
a Tabatabaenejhad - Department of Chemical Engineering ,Semnan University,Iran Petroleum research center, Department of chemical engineering , Sahand University of Technology ,Iran
e Khodapanah - Department of Chemical Engineering ,Semnan University,Iran Petroleum research center, Department of chemical engineering , Sahand University of Technology ,Iran

Asphaltenes are the heaviest constituents and most polar molecules in crude oil . Asphaltene deposition in reservoir , surface facilities and tubing can cause major problems during oil production , transportation and processing .Changes in reservoir parameters such as pressure, temperature and composition may cause asphaltene deposition from the crude oil. Therefore asphaltene can deposit during pressure, temperature and composition changes. Gas injection particularly CO2 gas, that is regarded as one of the most efficient methods of oil development, because of thermodynamic condition changes may cause asphaltene deposition which seriously influences production.This paper describes the effect of residence time and temperature on asphaltene deposition during CO2 gas injection to two Iranian oil samples(Ahwaz and Paydarshargh oil).The amount of asphaltene precipitation in the mixture of oil and CO2 gas was measured by using filtration . Then the experimental results were plotted as a graph and were accompanied with SEM images.

Asphaltene, CO2 injection, Residence time, Temperature