Numerical Simulation of Scattering Waves in VTI Media Based on the De Wolf Approximation

Abstract

To overcome the problem of calculation errors in the Born approximation when the forward accumulation effect is strong in VTI media, this article combines the De Wolf approximation method with VTI media to propose a numerical simulation method for scattering waves in VTI media based on the De Wolf approximation. Scattering equations are divided into forward and backward scattering equations, and the Born series is renormalized to improve its convergence in VTI media. During the calculation process, multiple interlayer waves are ignored, and only multiple forward and one backward scattering signals are retained. To accelerate computational efficiency, thin slab approximation and screen approximation methods are employed for rapid implementation. I use the concave model and complex model for algorithm testing, and the research results demonstrate that the De Wolf approximation can effectively mitigate the issue of calculation errors in the Born approximation, as well as reveal the propagation law of seismic waves in VTI media. Due to the influence of the anisotropic parameters of the medium, there may be phase deviations in the forward modeling records of seismic waves using the thin slab approximation method and the screen approximation method; because the thin slab approximation method and the screen approximation method only account for one reflection, there are no signals of multiple waves in the seismic records, and the comparative results verify the effectiveness of the algorithm.