摘要
The authors studied the thermal stability of oil in the Tarim Basin, especially researched the compensating effect of low geothermal gradient and quick deep burial process, considered that the depth where oil cracking began is at 9 000~10 000 m or deeper, and the correspondent reservoir temperature is higher than 210 ℃, a mount of oil may exist above this depth. Through the research of key geosciences problem of hydrocarbon migration and accumulation, it demonstrated that hydrocarbon mainly accumulated in Late Hercynian stage in the platform area, and hydrocarbon generated from source rocks are primarily charged into steadily existed paleo-uplifts and the slope area; during Late Hercynian stage, those carbonate reservoirs were buried in the depth of 800~2 500 m and karst reservoirs developed, which is the base of blanket hydrocarbon accumulation and consequently implied that reservoirs located in the slope area buried in depth of 7 000~9 000 m will be the important prospecting region of black oil and condensate oil.