The Study Of The Sediment Source And Diagenesis Of Shahejie Formation In A Steep Slope Zone Of The Northern Dongying Sag

A steep slope zone in the north of dongying sag is located in the southeast of iyang depression in the bohai bay basin.It is a steep slope belt controlled by the basement faults(Chen Jiazhuang fracture)and the convex wing of ups and downs in geomorphology.Glutenite reservoir with rich oil and gas resources in the study area is an important prospecting direction of shengli oilfield.Due to the complex source in this area,the differences in sedimentary,tectonism frequently,the strong reservoir heterogeneity and the difficult prediction high permeability zone for the development of reservoir.Therefore,it is necessary to further clarify the area of the source of the sediments and the provenance and diagenesis on reservoir control function.In this paper,we obtain the following:(1)Using the method of microscopically thin section identification,statistics Analysis of the steep slope zone in the north of dongying sag sediment rock constituents,typomorphic characteristics of quartz,lithic component,heavy mineral assemblages,etc.The results show that five big provenance in the study area.They are respectively the Binnan sedimentary area,lijin sedimentary area,the west of Shengtuo sedimentary area,the east of Shengtuo sedimentary area and Yonganzhen sedimentary area.Sediments mainly from Binxian uplift and Chenjiazhuang uplift.(2)Lithic types,heavy mineral combination characteristics,combined with the geochemical data analysis in the steep slope zone in the north of dongying sag show that parent rock composition mainly includes the granite gneiss from the Archaean group,the medium acidity of the continental island arc volcano rock and Mesozoic carbonate rocks.(3)For the study area diagenesis,by using casting thin section identification,scanning electron microscope and so on,the study found that the reservoir of Four section of Shahe Street Group is mainly experienced early compaction and cementation,late dissolution and cementation.Early compaction and cementation destroyed the primary pores of the reservoir,and Reduce the porosity.But cement formed by surrounding particles can suppress the compaction effect and have a protective effect on the reservoir porosity.The late dissolution is the key to the formation of secondary pores.But the late cementation is the most destructive to the reservoir.It can damage the formation of secondary pores in the late stage and reducing reservoir performance.(4)By comparing the diagenesis of different source regions found that there is a coupling relationship between matter source and diagenesis.Different parent rock composition is different to the effect of diagenesis on reservoir formation.The more rigid particles,the stronger the ability to resist compaction.Primary porosity is very developed.On the contrary,the primary porosity is low.The more gneiss,the less cementing material in later stage.On the contrary,there are a lot of later stage of cement content.And the porosity is low.Under normal conditions,if the easy dissolve particle content is high,the corrosion strength.