Structural characteristics and hydrocarbon accumulation in Qiunan—Yaken area of Kuqa sag

Qiunan- Yaken area is across front zone of the foreland thrust- folded belt and the front peripheral belt,with good oil and gas geological conditions and complicated tectonic deformation.In comprehensive application of outcrops,seismic profiles and drilling data,on the basis of structural-stratigraphic combination and deformation characteristics,three tectonic deformation layers have been divided,namely the upper part(from Neogene Kuqa formation to Quaternary),the middle part(from lower Cretaceous to Neogene Jidike formation) and lower part(from basement to lower Cretaceous Yageliemu formation).Since Pliocene Kuqa formation sedimentation,at least two phases of compressive tectonic deformation have been undergone in this area,which led to different structural deformation layers and vertical stacked structure of different styles,and formed differential structural deformation controlled by multiple detachment layers.In combination with hydrocarbon accumulation conditions and drilled well analysis,the differential structural deformation is pointed to plays an important role in vertical hydrocarbon distribution of this area,the main controlling factor of hydrocarbon accumulation is the connection of oil- migrating faults,and the middle and lower parts of tectonic deformation layers are of better exploration prospects.