Study On High-Resolution Sequence Stratigraphy And Sedimentary Facies Of Dongying Formation In South Of LD10-1 Surrounding Area,Liaodongwan Depression

Based on the theory of high resolution sequence stratigraphy,the paper aims to study the Dongying Fomation of in south of LD10-1 surrounding Area,Liaodongwan depression.With observing and describing cores data,analyzing drilling data and sedimentary facies,interpreting 3D seismic sequence boundary,the paper establishes high resolution sequence stratigraphy framework firstly,identifies sedimentary facies types,summarizes the characteristics and controlling factors of sand body distribution,predicts the stratigraphic lithologic trap in study area.By using the method of high resolution sequence stratigraphy,this paper identifies 5 long-term base-level cycles surfaces,which were named:SBd3?SBd2L?SBd2U?SBdl?SBt2.So,the article divides the Dongying Fomation into four third-order sequences,which were named SQd3,SQd2L,SQd2U,SQdl.Furtherly,this paper distinguishes 3 mid-term cycles in SQd3 sequence,7 mid-term cycles in SQd2L sequence,7 mid-term cycles in SQd2U sequence,which in all 17 mid-term cycles.According to the detailed core observation and analysis of single well facies,cross sections facies and seismic data,the sedimentary facies distribution are identified in Donying Formation within this paper.The study shows that six kinds of sedimentary systems were developed in this area,including meandering river delta,braided delta,fan delta,beach bar,slumping turbidite fan and lacustrine.In plane,the south of the area mainly developed fan delta and braided delta,the center of the area developed beach bar firstly,and then developed braided delta,the north of the area mainly developed meandering river delta.In vertical,the fan delta evolved into braided delta in slope of LD10-1S,the beach bar evolved into meandering river delta,and then evolved into braided delta in SZ36-1 area.The article analyses the laws and controlling factors of reservoir distribution.Also,those key sand bodies are precise described in this paper.The results show that the source area controls the sedimentary facies types,the sequence evolution controls the size of sand body,the sequence interface properties controls the position of sand body,the slope-groove systems control the distribution of sand body,the fault combination systems control the pattern of sand body.Based on the research of sedimentary system,and combined with the hydrocarbon accumulation condition and controlling factors,this paper makes prediction about the favorable horizons for subtle reservoir exploration,which are SQd3 and SQd2L.And predicts five potential exploration target areas:the slope of LD10-1S,LD10-3 structure,the down thrown of LD10-2 structure,the west of steep fault belt of LD10-1,and the LD10-1S structure.Then,the article puts forward seven stratigraphic lithologic trap exploration targets.