THE SEQUENCE FACIES MODEL AND THE SANDBODY DISTRIBUTION OF THE THIRD MEMBER,SHAHEJIE FORMATION IN XINKAI TO DONGJIAGANG AREA

According to the synthetical analysis of drilling,well logging,seismic and test data,it is recognized the third Member of Shahejie Formation is a Ⅰ-type sequence of the third order in the slope zone from Xinkai to Dongjiagang in the Liaohe Basin.LST is dominated by alluvial fan facies which are composed of mauve and hoar heavy bedded conglomerate mingling mudstone.TST is typically characterized by lake facies which are composed of deep-grey and brown-grey mudstones interlayering sandy mudstones,to HST the facies are switched to fan-delta ones which are composed of interbedded light-colored sandstone,conglomerate and dark-colored mudstone.The evolution of sequence depositional facies corresponded above is LST alluvial fan→TST lake→HST fan-delta adjacent to alluvial fan.It is pointed out that LST alluvial fan and HST fan-delta facies are favorable for the formation of reservoir sandbodies,and TST lake facies are favorable for development of source rock.