Fereidun Fesharaki, chairman of Honolulu-based FACTS Global Energy, says crude oil prices may fall to $40 a barrel this summer as U.S. stockpiles increase.

There may be a scenario where “sometime in the middle of summer, there will be a $20 drop in the price of oil befcause of the huge inventory build-up taking place,” Fesharaki said at a Australian Petroleum Production and Exploration Association meeting in Darwin, Australia. Bloomberg News quoted Fesharaki as saying OPEC would become active and cut output “if prices go down to $40 a barrel again.”