A 2.5-dimensional viscoelastic wave numerical simulation method and device in the frequency domain

Abstract

Embodiments of the present invention provide a 2.5-dimensional viscoelastic wave numerical simulation method and apparatus in the frequency domain. The method comprises: establishing a 2.5-dimensionalviscoelastic wave equation in the frequency domain; determining an equivalent integral weak form of the 2.5-dimensional viscoelastic wave equation in the frequency domain; obtaining a finite elementcontrol equation by using the discrete of bilinear triangular elements; loading 3D point sources in the frequency domain; loading the stiffness to weaken the absorption boundary condition; determininga wavenumber sampling strategy, wherein the finite element control equation is large sparse linear equations, and a direct solution method is used to solve the equations to obtain a frequency-wavenumber domain wave field; and using a complex Simpson numerical integration method to approximate the spatial inverse Fourier transform to obtain a three-dimensional viscoelastic wave field in the frequency domain. The present invention provides an accurate forward modeling method for 2.5-dimensional viscoelastic wave multi-scale full waveform inversion, and the method can adapt to any undulating surface complex medium, has a good absorption effect of the absorption boundary condition, and has high calculation efficiency.

Description

technical field [0001] The invention relates to the field of exploration geophysics, in particular to a frequency domain 2.5-dimensional viscoelastic wave numerical simulation method and device. Background technique [0002] Full waveform inversion is considered to be the ultimate method to solve the problem of seismic wave imaging, and one of its cores is seismic wave forward modeling. Usually, because the 2D seismic wave forward modeling assumes that the seismic source is a line source, the dynamic information between the simulated record and the actual field data is quite different, so the 2D forward modeling cannot be directly used in the full waveform inversion of the field data . Although the 3D forward simulation is closer to the actual field data, the amount of calculation is huge at present. The 2.5-dimensional method is to load a point source in a 2-dimensional medium to obtain a 3-dimensional seismic wave field. At the same time, the calculation efficiency is gr...

AI Technical Summary

Problems solved by technology

Usually, because the 2D seismic wave forward modeling assumes that the seismic source is a line source, the dynamic information between the simulated record and the actual field data is quite different, so the 2D forward modeling cannot be directly used in the full waveform inversion of the field data

Although the 3D forward simulation is closer to the actual field data, the amount of calculation is currently huge

At present, forward modeling based on viscoelastic media has been developed in 2D or 3D, but 2.5D viscoelastic wave simulation for exploration seismology is still not documented

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