Abstract:

An analysis of the provenances and sandbody types of the upper4 th member of Eogene Shahejie Formation（Es 4 ）in the Shengtuo area of the Dongying Sag，the BohaiBay Basin was carried out based on an integration of seism ic，logging and geochem ical data，a paleogeomorphologic analysis，and a study of lithic fragment assemblage，ratio of characteristic elements and net-to-gross ratio.The results indicate that there were two different provenance systems during the deposition of the upper Es 4 :one on the upthrow of the Tuo94fault and the other on the upthrow of the Shengbei fault.Controlled by these two systems，various types of sandbodieswere developed in the area，including nearshore subaqueous fan，sublacustrine fan and channel turbidite.The nearshore subaqueous fansmainly occur on the downthrow of the Chennan fault，the sublacustrine fansmainly occur on the downthrows of the Tuo94fault and the ShengbeiFault，while the channel turbidites occur in the trough along the Shengbei fault.It is suggested that the braided channel sandbodies and channel turbidite have the bestporoperm characteristics，and their reservoir space is composed of fractures and dissolved pores.Therefore，the braided channel is a favorable facies belt for oil and gas accumulation.

Key words: provenance direction, sedimentary type, Shahejie Formation, Shengtuo area, Dongying Sag, BohaiBay Basin