Hydrocarbon Accumulation Conditions Of Carboniferous Pyroclastic Rocks In Block Su13 Of Junggar Basin

The Chepaizi bulge is located in the northwestern margin of the Junggar Basin.It is in the western uplift of the Junggar Basin in the regional structure,adjacent to the Zaire Mountains in the west and north,and connected to the Sikeshu Sag in the south,and the Hongche Fault belt in the east and the Changji Sag and the Zhongguai bulge are connected.As one of the most important oil-bearing areas in the Junggar Basin,the Su13 well area is also a favorable area for oil and gas accumulation.In recent years,oil and gas exploration of the Carboniferous pyroclastic rocks in the Sul 3 well area has continuously made new discoveries.The volcanic clastic reservoir has become an important type of oil and gas reservoir,and its status has become increasingly important.The development and distribution of volcanic clastic reservoirs are extremely irregular,the concealment is very strong,and its accumulation rules are quite complicated.In this paper,the combination of logging data,coring data and logging curve,using the theory of sequence stratigraphy and petrology,the lithology identification of Carboniferous rocks,and finally the main developed tuff mudstones in the Carboniferous in this area,tuff,limestone,tuff fine sandstone,tuff,and a small amount of silicified mudstone,gray mudstone and gravel mudstone,which is a volcanic sedimentary rock development zone far from the volcanic eruption.The Carboniferous in the Su13 well area has the Baogutu Formation and the Tailegula Formation,which are most widely distributed in the Baogutu Formation.On the basis of the study of basic geological characteristics,using the theory of petroleum geology and reservoir geology,the study area has been studied in terms of living,storage,cover,transportation.The results of the study indicate that the Sikeshu Sag are far from the car bulge Relatively close,the oil and gas generated by the Jurassic in the Sikeshu Sag has the characteristics of short migration distance,high hydrocarbon supply efficiency and low oil and gas loss.It is the main source of crude oil in the Su13 well area;Carboniferous reservoir storage The space is mainly for the dissolution of pores and fractures,and the relationship between reservoir physical properties and oil-bearing properties is determined.It is concluded that reservoir physical properties are one of the main controlling factors affecting hydrocarbon accumulation;the top cover of Carboniferous is a large-scale accumulation of Carboniferous.Provided that the cover layer is an important factor for the large-scale accumulation of Carboniferous;the Jurassic blanket sand is provided for the lateral migration of the oil source in the Sul3 well area,and then it is laterally docked into the Carboniferous,blanket sand and fault through the fault.It is a key factor for hydrocarbon migration and accumulation.Within the critical width,the density of fracture development is inversely proportional to the distance from the fault.The closer the fault zone is,the denser the fracture development is advantageous.By anatomizing typical reservoirs,the conditions of life,storage,cover and transportation were further clarified,and the hydrocarbon accumulation model was established,and a prediction well position was proposed.This study is of great practical significance for the exploration and development of Carboniferous in the Su13 well area,and has important theoretical significance for the study of hydrocarbon accumulation conditions of volcanic clastic rocks.