A Study of Migration and Accumulation of Oil and Gas in Xiazijie Area of Northern-western Parts of Zhungaer Basin

There is great difference in petroleum properties and geochemistry between the falut zone and the anticline belt. In fault zone petroleum (oil) density is between 0.73 g/cm³ and 0.86 g/cm³, the average content of CH₄ is 87.06%, the value of δ¹³C₁ is between -40.96 ‰ and -44.22 ‰; petroleum density in anticline belt is between 0.85 g/cm³ and 0.95g/cm³, the average content of CH₄ is 73.59%, the value of δ¹³C₁ is between -46.38 ‰ and -47.83 ‰. All of this indicated that petroleum accumulated in multi-stage, fluvial sand body is first filled with mature petroleum in anticline belt, and high mature petroleum generated in middle-late Jurassic accumulated in fault zone.