Through comprehensive study on the cores and well logs, the author believes that the sandstone mainly comes from subaquatic distributary channel and mouth-bar. Since a great deal of oil and gas was expelled from source rock, three diagenesis happened, calcite cementation, dissolution of feldspar, the matrix corrosion by acid. Considering the sedimentation and diageneses, during the period a great deal of was expelled, the migration path mainly lies in the area of xifeng, qingyang and zhenyuan.