Oil Sands Forming Model and Character in the Northwest Edge of the Junggar Basin, China

摘要

The Junggar Basin has the basic conditions for giant oil-sand mine to form and it is the hot point for exploration & development of oil sands. Multi-layer source rocks deposited in The Manas Lake Depression have produced abundant hydrocarbon in the course of multi- phase tectonic movement and they were the source of oil sands. Many unconformities formed also in the course of multi-phase tectonic movement were the main pathway of lateral movement of hydrocarbon and the welldeveloped abnormal faults were the main vertical pathway. The sands bodies of fluvial facies in alluvial fans in front of the Zhair Mountain offered a very favorable reservoirs for oil-sand mine. Hard biodegradation make the viscosity of hydrocarbon heavier and heavier. The hydrocarbon seized on the surface of sands, and then oil sands were formed. The peculiar characters of the northwest edge of the Junggar Basin make the oil sands occur at the compressive side of the basin. And the lateral distribution of oil sands mine is bigger and the scale is smaller relatively. The fault' openness, fossil landscape, sedimentary facies, oil viscosity etc. have controlled the abundance and distribution of oil sands.