Abstract：Deep complex structures of the study area lack geological understanding and drilling data,and the horizon-based tomography is unable to establish an accurate velocity model.In order to improve the imaging accuracy,we use a Gaussian beam based on grid tomography modeling tools provided by the GeoEast System.Firstly,we use constrained velocity inversion (CVI) to obtain a smooth initial velo-city model,then a 4D denoising technique is used to optimize CIP gathers to improve signal-to-noise ratio (SNR),and to make sure that the residual depth difference is highly reliable.On this basis,formation dip constrained grid tomography modeling is directly conducted.The final Gaussian beam migration imaging is much improved with grid tomographic velocity update and iteration.Fracture distribution characteristics of the study are highlighted,and fault-block traps are depicted.
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