Research On The Sedimentary And Reservoir Characteristics In Es3 Of Gubei Subsag

Gubei sag in Jiyang depression of Eastern Zhanhua depression,controlled by Chengdong,Zhuangxi and No.five pile distribution.The comprehensive application of seismic,well logging and mud logging and analysis test data,on the basis of sequence stratigraphy,sedimentology and petroleum geology theory and method,to the research area of the third member of Shahejie formation were bound of factors of stratigraphic framework,depositional model,period of glutenite,microscopic characteristics of the reservoir and the effective storage layer.Gubei subsag are three period can be divided into a total of 14 0-13 sand group,the 0-1 corresponding Es3 sub section,2-8 corresponds to the third member of Es3,9-13 corresponding Es3 sub sections.The main types of the three stages of sand are delta facies,fan delta facies,and near shore underwater fan facies.Chengdong provenance in 13 sand group only the northern basin sediments nearshore fan,12 groups of sand deposition phase begins to North South double channel developed fan delta-sliding collapse fan sedimentary system,fan delta bottom-up scale decreases.Long beach matter originating from the 12 sand group began development of fan delta slump fan sedimentary system,fan delta bottom-up scale.Island,Ken East Development normal delta,in sediment by the Gubei nose like structure belt control two provenance mainly deposited in the east wing,gradually increasing the size of bottom-up,Es3 only accept Island sediment source.On the basis of sequence stratigraphy,tectonic lake level changes in the analysis based on,of Gubei subsag are three glutenite were stage division.West Chengdong steep slope of the transverse distribution of the glutenite,features show vertical retrogradational progradational.Changdi fault zone distribution of glutenite fan body before the product limitations,early,late retrogradational fan.The period of control Basin fault controls the development of sand body,and the change of lake level controls the pattern of sand body.In the direction of the vertical material source,the fault development of the secondary causes the migration of the fan body.According to the 4-7 sand group of the main development section of sand reservoir in the north of the area,the sedimentary cycle is divided into 6 sedimentary units.Based on the analysis of well logging facies,the sedimentary microfacies of the middle section of the sand in the north of the area were analyzed.Among them,the 5-1 sand group to promote the farthest distance,the largest spread.Es3 is mainly feldspar sandstone and lithic feldspar sandstone.The pore types are mainly secondary pores,and the dissolved materials include feldspar,debris and a small amount of carbonate cements.Gubei subsag are three sections into diagenetic stage to the early diagenetic B to become rock A2 in the early stages,the Western subsag in deep shows the late diagenetic stage,and the eastern depression and shallow remain in more early.Different source reservoir layer significantly,which Ken Island East storage layer of best,Causeway provenance times,Chengdong provenance is the worst.The development of effective reservoir is controlled by sedimentation and diagenesis.On the basis of the above research,the identification and classification of reservoir diagenetic facies in the middle area of the third member of the sand in the north of the area were identified,and the four types of compaction,carbonate cementation,dissolution and weak cementation were identified.Combining the understanding of sedimentary facies,diagenetic facies and the actual capacity favorable area prediction,advantageous area belt of delta front underwater diversion channel and mouth bar and dissolution phase or weak cementation dissolution overlapped the region.