APPROACH TO GENERATION, MIGRATION AND ACCUMULATION OF OIL AND GAS IN THE SIKESHU DEPRESSION, THE JUNGGAR BASIN

The Sikeshu Depression initiated its subsidence from the Jurassic and the most severe subsidence occurred in Neogene. Two suites of source beds, i. e the Jurassic coal series and the sequences of the Anji and the Hehai formations of Eogene are developed, of which the Jurassic coal series is widely spreaded with a great thickness and richness of organic matter, and high levels of thermal evolution, being considered as a major contributor to hydrocarbons in the area. However, migration is oriented to the Tuositai Region and the Dushanzi Anticline. The various types of traps occurred in the former and the deep-seated traps in the lattter are favourable places for hydrocarbon accumulation.