The Research Of Control Beam Migration Methods In Vertical Transversely Isotropic (VTI) Media

In the process of seismic exploration and development,the quality of seismic data processing will have a great impact on later interpretation.To obtain good results,we must fully consider the seismic wave propagation characteristics of the exploration area and the characteristics of seismic data,and make it more suitable for the treatment of the media in the exploration area.Studies have shown that there is a wide range of anisotropy in the subsurface media.To obtain high-precision migration imaging,the anisotropy of subsurface media must be considered,which is more in line with the actual propagation characteristics of seismic waves.At the same time,there are various random noise disturbances in actual seismic data.Random noise interference should be eliminated as much as possible to improve the signal-to-noise ratio of the imaging section.For this reason,this paper studies the control beam migration imaging method in anisotropic media.This method can better image the low signal-to-noise ratio data in the anisotropic detection zone.Gaussian beam migration has the advantages of high imaging accuracy,flexibility,and high computational efficiency.On the basis of previous studies,this paper extends the traditional isotropic Gaussian beam migration imaging method to VTI media,and proposes a Gaussian beam depth migration imaging method for VTI media,Based on this,a?-p threshold control migration method is developed.The research work includes the following three aspects:(1)Derived the basic theoretical formula of Gaussian beam,the basic properties of Gaussian beam;(2)Derived the ray tracing formula of anisotropic medium proposed by Zhu et al.,and simplified theformula.A VTI medium ray tracing algorithm was developed and applied to Gaussian beam migration imaging.(3)Based on the difference of the energy of the underground structure reflection and interference signal after the local tilt stacking,the Fresnel radius weight is set to set the threshold,and the ?-p threshold offset VTI-controlled beam migration imaging method is developed.