Sedimentary And Reservoir Characteristics Of The Slope-slumping Gravity Flow

Recently,deep-water petroleum exploration has been one of the most important areas around the word's oil-gas exploration,and the great hydrocarbon discovery in Bohai Gulf and Erdos Basin has also proved that lacustrine oil and gas exploration became more significant in the future.Large slope-slumping gravity flow deposits fed by delta front,which developed in the middle sub-member of 3rd member,Shahejie Formation in Dongxin area,Dongying sag,has its regional sedimentation and reservoir characteristics,as well as its sedimentary models.It would improve the effect of exploration and clear the sedimentation units and regularities of distribution.Under the correlation geology theory,large quantity work in core data analysis,3D-sesmic,and well logging interpretation demonstrated the sedimentary unit classification,sedimentary and reservoir characteristics,as well as model characteristics in the work area.Five sedimentation units were identified,i.e.MTDs,channel,lobe,debris tongue,and thin turbidite.MTDs consist of slide,slump and debris flow blocks.The transition channel is the main feature in the work area,and can be divided into two types: transition channel type ?(partial sedimentation)and transition channel type ?(partial erosion).Another type of channel has been found in this region,which is featured with weak erosion and less deposit,and could be named as by-pass channel.According to the genetic type of the slope-slumping gravity flow,there are two kinds of sedimentary models.One is controlled by debris flow(debris fan)and the other is controlled by turbidite(turbidite fan).On the basis of sediment research,this thesis analyzed the relationship between reservoir petrology,physical characteristics,and oil bearing possibility,compared the reservoir quality between different sedimentation units.The results show that transition channel sand bodies and debirs tongue sand bodies were high quality reservoir,posteriorly was lobes sand bodies.Slides and debris blocks has general reservoir property,slumps and thin turbidite reservoir property is relatively poor.In this thesis,the research of slope-slumping gravity flow and its reservoir characteristics can deepen the understanding of distribution of the gravity flow in rift lake basin,and also provide geological basis for petroleum reservoir exploration.