Abstract: The Permian hydrocarbon source rocks in the central depression of the Junggar Basin are the most important source of oil and gas in the basin. To sort out the hydrocarbon-generation evolution and enrichment patterns of multi-phase oil and gas under the "source control" background, basin simulation and experimental analysis techniques were employed to reconstruct the thermal evolution history, hydrocarbon generation history, and accumulation process of the Permian hydrocarbon source rocks in different hydrocarbon-rich depressions of the central depression. The study shows that the Permian hydrocarbon source rocks began to mature in the Late Triassic and are currently mainly in the high-maturity condensate gas generation stage, mostly reaching the over-mature stage in the depression centers. The hydrocarbon generation process of the Permian hydrocarbon source rocks can be divided into three enrichment patterns: continuous injection of mature oil-rich and gas-poor type, multi-stage adjustment of deeply buried high-maturity gas-rich type, and early loss of early-mature oil and gas-rich type, with the peak hydrocarbon generation rate reaching up to 450 mg/g. The Mahu Sag tight oil and shale oil, the conventional oil of the Triassic system in the western annular zone of the Shawan Sag (west of Well Pen 1), the tight gas of the Permian system in the eastern annular zone, and the shale gas within Permian source in the Dongdaohai Sag are the four oil and gas enrichment areas in the study area. The research results can provide important support for the next step of oil and gas exploration in this area.

Key words: hydrocarbon source rock, thermal evolution, hydrocarbon accumulation, Permian, Junggar Basin