 After World War II, the shale oil production was ceased, but 100 Fushun-type oil shale retorts were restored in 1949.In 1950, total 266 retorts were in operation, each with the capacity of 100–200 tons of shale oil per day.With the discovery of Daqing oil field in the 1960s, the shale oil production declined and Sinopec, an operator of shale oil production these times, shut down its oil shale operations in the beginning of the 1990s.