Evaluation Of Hydrocarbon Generation Potential Of Carboniferous Source Rocks In The Northern Margin Of Junggar

In this paper,based on the collection and arrangement of relevant Carboniferous geological data in the northern margin of Junggar and previous research results,combined with field surveys and geological profile measurements,the Carboniferous source rocks are sampled and analyzed.Among them,the thickness of the Carboniferous source rocks,research and analysis of the organic geochemical characteristics of the source rocks in the outcrop area,clarify the development of the Carboniferous source rocks,and evaluate the source rocks.There are source rocks in the upper and lower Carboniferous in the northern margin of Junggar.Due to the differences in sedimentary environment and other factors,the major source rocks developed in different regions and the thickness and thickness varied greatly.According to the comparison,the Lower Carboniferous is mainly divided into the Nalinkala Formation,Heishantou Formation and Jiangbasitao Formation;the Upper Carboniferous is mainly divided into the Taileigula Formation and Qiaqihai Formation;the main source rock types are dark mudstone,Carbonaceous mudstone and shale.The Jiangbasitao Group is in angular unconformity contact with the underlying Heishantou Formation and the overlying Nalinkala Formation,and the Nalinkala Formation is also in angular unconformity contact with the upper and lower strata.The Lower Carboniferous Jiangbasitao Formation of Carboniferous is mainly shallow marine-coastal facies deposition;the Nalinkala Formation is mainly marine-continental alternating facies or alternate deposition of coastal facies-continental facies;the Heishantou Formation is mainly from coastal facies to shallow sea continental shelf facies Sedimentation;the Upper Carboniferous Qiaqihai Formation is mainly delta deposits;the Taileigula Formation is mainly oceanic island arc shallow-semi-deep marine sediments.The source rock layers with better hydrocarbon generation potential of the Carboniferous in the northern margin of Junggar are mainly the Carboniferous Taileigula Formation and Jiangbasitao Formation,followed by the Nalinkala Formation and Qiaqihai Formation.The source rocks of the Taileigula Formation are 153-960meters thick.The source rock samples have good organic matter abundance.Types of organic matter are mainly type II and III,followed by type I,which has a high degree of thermal evolution and reached maturity-high maturity stage;the source rock of the Jiangbasitao Formation is 200-300 meters thick.The source rock sample is of moderate organic matter abundance,the organic matter type is II₂-III,and the degree of thermal evolution is high,mainly at the high maturity stage.Nalinkala The source rocks of the Formation are mainly exposed in the northern shore of Wulungu Lake,and are distributed in an east-west band.The source rock samples have medium organic matter abundance,the organic matter type is mainly type II₁,and the degree of thermal evolution is high.The source rock of the Qiaqihai Formation is 45-120 meters thick.The source rock sample has poor organic matter abundance-moderate,the type of organic matter is type III,and the degree of thermal evolution is high,reaching the mature stage.In the northern margin of Junggar,the source rocks are mainly distributed in the Jimunai Depression,Fuhai County-Fuyun County-Qinghe County,Wulunguhu North area,and Qialeishenhai North area.Therefore,the Carboniferous source rocks in the northern margin of the Junggar Basin have certain prospects for resource exploration.