库车山前带复杂区三维观测系统优化设计
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中图分类号：P631 文献标识码：A DOI：10.13810/j.cnki.issn.1000-7210.20240228
Abstract： The Kuqa foreland thrust belt is characterized by highly variable topography，complex near-surface structures，diverse surface lithologies，and intricate subsurface geometries.These factors colectively contribute to seismic data with low signal-to-noiseratio and poor imaging quality.To improve the quality of seismic acquisition data in this area，an optimization design method ofthe 3D seismic geometry is proposed for a complex area in the Kuqa foreland thrust belt. Firstly，a 3D geophysical model is constructed based on seismic，geological， and wel-logging data from the region，follwed by 3D wave-equation forward modeling and 3D seismic illumination.Secondly，the influence of geometry parameters on migration imaging and target-layer ilumination energy is analyzed both quantitatively and qualitatively to identify sensitive parameters and optimization directions. The suggestions for geometry optimization in this area are also proposed.The study concludes that shot-receiver density is a key factor affecting structural imaging and illumination.A density higher than 1.48 million traces per km2 is required in this area. Under a given shot-receiver density，a geometry with smaller receiver line spacing is more conducive to migration imaging.When receiver line spacing is less than 180m ，imaging accuracy for complex structures in the foreland thrust belt can be improved.Additionally，a wide-azimuth geometry is more favorablefortarget-layer ilumination and thin-sand identification，with a recommended aspect ratio greater than 0.8. The findings provide valuable references for the geometry design in other similar areas.
Keywords： Kuqa foreland thrust belt，dual-complex area，geometry optimization，3D forward modeling，3D illumination
Li Dajun，He Wei， Xu Kaichi，et al. Optimization design of 3D seismic geometry for complex area in the Kuqa foreland thrust belt[J]. Oil Geophysical Prospecting，2026，61（2） ：315-324.
0 引言
库车坳陷是塔里木盆地重要的天然气产区，具有丰富的油气资源[1-3]。（剩余12247字）