Abstract: The logging and formation test data as well as soluble organic matter feature of Cretaceous and Tertiary reservoirs in Kela-1 structure of Kuqa depression in Tarim basin are analyzed and the multi-period petroleum migration events are discussed. The study shows that Kela-1 structure was not a gas pool, but in the course of its geological history, the multi-period petroleum migration events even occurred here. And the prevalent occurrences of its multi-period/stage petroleum migrations become one of advantageous conditions for hydrocarbon accumulation in Kuqa depression. The key factor that the hydrocarbon accumulation really occurred by the multi-period/stage petroleum migrations depended on whether there existed complete trap( s) and deep fault linked to the reservoirs and the source rocks or not, because the existing gas pools are mostly resulted from an effective match between the complete trap(s) and such a deep fault.

Key words: Tarim basin, Kuqa depression, petroleum migration, trap, organic matter