A Study On The Structure Of Keshen Oil-gas Area Of Kuqa Depression

Kuqa Depression is a linear depression with abundant oil and gas resources that develops in Mesozoic and Cenozoic.The structure of Keshen oil-gas area of Kelasu tectonic zone in the Depression develops unconventionally.With the assistance of the drilling data,seismic layer labelling and figures of seismic interpretation,every set of the layers' distribution range,variation in thickness and tendency of the speed variation will be depicted subtly in this paper,which presents a systematic study on issues such as structure and salt tectonic of the Keshen oil-gas area in Kelasu tectonic zone of Kuqa Depression.The study results show these findings:(1)Keshen oil-gas area has experienced 4 evolutionary phases,namely late Permian---Triassic palaeo-foreland basin,Jurassic---Cretaceous down-warped basin,Paleogene---Miocene deflection basin of weak contraction and Pliocene---Quaternary intra-continent foreland basin.(2)Influenced by the strong napping effect of Himalayas' massif lifting,differential loading,gravity gliding and expanding effect,the form of salt tectonics in Kuqa area is extremely complicated and manifestations includes salt arch structure,salt-bath brazing,salt mound,salt diapir,salt depression and plenty of other structure types,among which salt arch structure,salt-bath brazing are most common.(3)Applying the brand new field geological outcrop digital applications to set up three-dimensional structural and geologic model of Keshen oil-gas area and in this way variation of salt-overlying structure can be depicted subtler and trap will be settled,thus a better understanding of the structure.