Grain inpermanent indoor storage, hay in a barn and silage in a covered silo may beconsidered protected.

The reservoir quality is strongly influenced by the depositional facies and diagenesis of the Chang 2 sandstones of braided river facies in Qinghuabian oil field.

Kulongshan Oil Reservoir, located in the south of the Qingxi Depression, Jiuxi Basin and overrided by the Qilianshan Mountain, is the primary producing area of the Yumen Oilfield.