Study On The Distribution Rule Of Turbidite Reservoir Of Middle Es₃ In Minfeng Sag

Minfeng Sag is located in the northern part of Dongying Sag.The Es3 layer has abundant turbidite sand body,and is the favorable oil and gas reservoir.Via comprehensively utilizing data of seismic,logging,mud logging and lithology,the paper establishes the stratigraphic framework of Middle Es3 in Minfeng Sag,and divides Middle Es3 into six stages.During the six stages,the main sedimentary facies of the NO.3 Member of Shahejie Formation from the Minfeng Sag are delta and deep water lake.The delta presents continuous progradation process from east to west.Four types of turbidite sand bodies are formed by the delta front slump,which are sliding turbidite sand body,slump turbidite sand body,debris flow turbidite sand body and far-source turbidite sand body.Four types of turbidite sand bodys are respectively provided with the typical sedimentary characteristics and They are high quality reservoir.The study finds that the distribution of turbidite sand body is controlled by the evolution process of delta deposition.In pace with the delta's constant progradation to the west,the turbidite sand bodies superpose mutually on vertical,and distribute along the delta front contour and present as “horseshoe” shape on plane.The turbidite sand reservoir pore mainly developed secondary porosity,the pore and throat are mainly middle porosity thin throat,low porosity thin throat and low porosity minuteness throat;Diagenesis is mainly on the compaction,cementation and dissolution,among them,the compaction,cementation may caused the loss of reservoir pore,the dissolution made the porosity improved.Therefore,this paper explores the distribution rule of turbidite sand body within Minfeng Sag,by virtue of the seismic inversion and attribute extraction approaches,as well as combining with single well data and conventional geological methods.