Influenced by the complex surface structures and subsurface geologic conditions,the seismic data acquired in the Kuqa Depression,Tarim Basin,is commonly featured by low signal-to-noise ratio and low quality of seismic profiles,which constrains petroleum exploration and development in the study area.During the DK 2D seismic acquisition in the Kuqa Depression,the wide line survey system and long geophone array receiving(9 strings of detectors used for huge thick loess accumulation zones,while 3 strings of detectors in three parallel lines used for complicated mountainous zones with ancient rocks at surface) were adopted as the core acquisition techniques,the detailed surface survey was performed,and seismic engineering remote sensing technique was used to select rational shot points and receiving points.In addition,the effective folds on geologic targets were enlarged,and the shooting and receiving conditions were enhanced.These measures helped increase the signal-to-noise ratio of single shot records and improve the quality of seismic sections.High-quality seismic data could thus be provided for identifying the structures in the Kuqa Depression.Successful pilot tests show that this technical approach can be popularized and applied in other areas with similar conditions.

Well HK-2 is located 320 km northwest of Atelao City of Atelao State,western Kazakhstan.Rock types of the Middle Carboniferous in Well HK-2 include dolostone,limestone,siliceous rocks,sandstone and claystone.Siliceous rocks and claystone are the dominant types with mixed components,frequent interclayering,abundant organic materials and floating and swimming microbials of deep water facies.The Middle Carboniferous in this area was identified as deposits of a deep water environment,according to the high content of siliceous radiolarian fossils in the rocks,the complete preservation of siliceous sponge spicules,combined with high content of organic materials,dark color,fine-grained components,muddy and siliceous components as the dominant ones,and single bioassemblages.It is still unclear whether deep water hydrocarbon accumulations exist in the Wulaer block where Well HK-2 is located.The authors propose that further studies should be carried out on deep water hydrocarbon accumulations.At the same time seismic profiles in this block and the adjacent blocks should be analyzed.