The Southern Margin Of Junggar Basin Hydrocarbon Source Rock Thermal Evolution History Of Hydrocarbon Generation And Oil And Gas Source Analysis

There is a low exploration degree in the southern margin of Junggar basin,where a large scale of petroleum reserves has not been found.According to the comparability of the geological conditions of hydrocarbon accumulation,The exploration for lower assemblage of foreland thrust belt in the southern margin of Junggar basin will be a major breakthrough.Based on the research achievements of hydrocarbon accumulation of complex tectonic belt in the southern margin of Junggar basin,this paper,comprehensively using a large amount of geology,drilling,seismic,testing data and single well and 3D basin simulation technology and focusing on the research of hydrocarbon forming evolution analysis of source rocks,analyses space distribution,thermal evolution and the history of hydrocarbon forming of multiple source rocks under the constraint of single well measured geothermal,Ro data.By combining with current sources and distribution characteristics of hydrocarbon,this paper distinguishes the effective hydrocarbon forming area and try to explain the difference between hydrocarbon source,accumulation conditions and hydrocarbon distribution in different area in term of hydrocarbon forming history of source rocks.Developing a deeper understanding of the control action of hydrocarbon source rock for hydrocarbon distribution in the southern margin foreland basin,so as to provide the guidance for further exploration and deployment.Above all,there are several innovative ideas as follow:1.The geothermal gradient in the study area is low,only 1.5 ~ 2.2?/100 m,geothermal gradient below 18 ?/ km as a whole.The southern piedmont belt geothermal gradient gradually reduce,is far lower than the eastern junggar,northwestern margin junggar and abdomen junggar.Low temperature is advantageous to the hydrocarbon potential of hydrocarbon source rock and late hydrocarbon generation.2.According to the actual measured data and the single well,3D basin simulation,combined with the oil and gas source comparison results.Quasi south foreland development in three sets of effective source rocks,which are Upper Permian,Jurassic and Cretaceous qingshuihe Formation of hydrocarbon source rocks respectively.Due to the low degree of thermal evolution,Ann set of haihe river group of hydrocarbon source rocks as invalid hydrocarbon source rocks,quasi south sag of four tree oil should be came from Jurassic hydrocarbon source rocks,rather than previously thought from the paleogene hydrocarbon source rocks3.The structure of the different zones in the study area-burial history,thermal evolution difference is huge.It is divided into four types: ?Late uplift type(Qigu fault fold belt),?continuous buried(urumqi-kuitun high-graded anticline belt),?late slowly buried(foreland slope belt),early shallow buried late rapid burial type(four tree hollow zone).?4.According to have been found from the Jurassic hydrocarbon source rocks of oil and gas distribution,and shows that the Jurassic hydrocarbon source rocks as hydrocarbon source rock,and widely distributed.The Jurassic source of oil and gas distribution in the study area has the following characteristics: The middle rich gas,oil and gas for the western coexist,oil-rich eastern.From west to east,hydrocarbon source rock maturity has increased after the first decreases and the maturity of natural gas also has the same change rule,shows that the hydrocarbon source rock maturity of oil and gas composition and maturity of oil and gas has obvious control effect.