Oil accumulation related to migration of source kitchens in northwestern margin structural belt, Junggar Basin

According to the analyses of hydrocarbon-source correlation, hydrocarbon accumulation periods and source kitchen migration, the present hydrocarbon distributions in the northwestern margin of the Junggar Basin are controlled by three sets of source kitchen migration. The natural gas which generated during the early stage from source kitchens in the Jiamuhe Formation has not been preserved, and the present location of source kitchens controls reservoir distribution. The source kitchens in Fengcheng Formation at the centre of the Mahu Sag can not generate gas since they are over-matured. Only the source kitchens at the margin of the sag can generate hydrocarbon and control the location of oils generated from them. The source kitchens in Wuerhe Formation can still generate oil and gas in the center of the sag and also control the location of oil generated from them. Because of the different hydrocarbon-generation intensity for the same source kitchen during different geological periods and different source kitchens at the same geological period, different hydrocarbon supply modes develop and control the location of hydrocarbon in the northwestern margin of Junggar Basin.