The upper member of Guantao Formation consists mainly channel bar

point bar

arrested deposits on valley floor

natural levee

crevasse splay

alluvial lake and alluvial flat microfacies.The diposits are principally sandstone and siltrock with mid lower composition maturity and small cross bedding.1～4 sand set are meandering stream deposits

5～6 sand sets are braided channel deposits.The reservoirs of the study area have good physical property

big porosity and high permeability.Sedimentary facies zones controlled the variation of the physical property and improved the porosity and permeability.The channel bars and point bars contain less remaining oil

but alluvial flats and natural levee have relatively rich remaining oil.