Study On Organic Geochemical Characteristics Of Permian Argillaceous Shale And Formation Conditions Of Shale Gas In Chaiwopu Sag

Junggar basin is a typical polycyclic superimposed basin in western China,and Chaiwopu sag is a secondary structure unti of Junggar basin,located in the southeastern margin of Junggar Basin.At present,many scholars at home and abroad have invested a great deal of research into the Permian conventional oil and gas in this area,and obtained a lot of exploring development and scientific research achievements.However,the study of unconventional oil and gas is relatively weak,so we should strengthen the study on unconventional oil and gas of Chaiwopu sag,study on its shale gas accumulation conditions,it will have an important impacts in exploration and development of Permian unconventional oil and gas in Chaiwupu sag.On the basis of synthesizing the previous research data,this paper is based on field geological investigation,sample collection and indoor test and analysis to study the lithologic characteristics of Permian different strata,source rock lithology and organic geochemical characteristics of the source rocks in Chaiwupu sag in depth,and the following conclusions have been obtained:The Permian system is the main stage of source rock in Chaiwupu sag,and the shale is located in Yongfeng subsag,sangcheng subsag and Sangezhuang subconvex.The shale thickness is 300-700m,reaching the thickness standard of continental hydrocarbon source rocks.Mud pages of the Permian Lucaogou formation in the study area,rock belongs to very low porosity and permeability type,organic matter pores and microfractures are well developed,which provides a good reservoir space for shale gas.The organic geochemical characteristics of Permian shale in Chaiwupu sag indicate thatLucaogou Formation Group Sample organic matter abundance is mainly among 1.14%⁶.68%,belongs to good-best source rock,the type of organic matter is?₁ type Kerogen,the second is?type kerogen,organic matter maturity is high,mature-high-mature evolution stage.The abundance of organic matter in the muddy shale of the Red Goose pool is mainly between 0.94%².90%,evaluation of the best source rock,the main organic types of?-type kerogen,followed by the?₂ type,the sample maturity compared to the Lucaogou formation group,except a few samples for the low stage,the remaining samples are in the mature stage.Comprehensive analysis of shale thickness,reservoir characteristics and organic geochemistry characteristics of Permian strata in Chaiwupu depression,Junggar BasinPreparation of shale gas reservoir conditions.