Reserve growth assessment of known oil fields is an important task in resources evaluation.The reserve growth forecast models differ from region to region due to different geological and development conditions.By using modified Arrington method

this paper analyzed the recoverable reserve variation with oilfield age

established a mathematical model between cumulative growth factor and oilfield age and forecasted the potential reserve growth in the future.Meanwhile

we studied the actual reserve growth of oilfields with different reserve scales and discovery periods.Results show that the reserve growth model of Zagros Basin follows a power function.The recoverable reserves of the known oilfields in Zagros Basin will increase 20.7% in the next 30 years.The reserve growth rate of Zagros Basin is unstable and stepped in the exploration and development process.Oilfields with recoverable reserves larger than 150 MMb in this region have greater positive growth potential and reserve growth rates of the known oilfields are much larger than that of the newly discovered oilfields in the same period.