优化近似解析离散化方法的二维弹性波波场分离模拟

Numerical simulation of elastic wave separation in 2D isotropic medium with the optimal nearly-analytic discretization

近似解析离散化方法是近年来出现的一种数值模拟方法,其特点是在高阶有限差分中引入了位移梯度,与四阶Lax-Wendroff修正格式数值模拟方法相比,该方法能够在大网格条件下有效地压制频散、提高计算效率和精度。本文首次将优化的近似解析离散化方法应用于弹性波场纵横波分离模拟,建立了波场分离的差分格式。通过模型试算分离出来的纵横波特征更加清晰,说明了该方法的有效性和实用性,对于认识地震波在复杂介质中的传播规律有着重要的意义。

The optimal nearly-analytic discretization (ONAD), a newly developed numerical simulation, is characterized by the use of the displacement gradient in the high-order finite difference. Comparing with the Lax-Wendroff numerical simulation, the ONAD method can effectively restrain the dispersion in a large grid, thus improve the computational efficiency and accuracy. In this paper, we apply the ONAD method to an elastic wave field separation simulation, and set up difference formats of the wave field separation simulation. Based on our model tests, characteristics of P- and S-waves are clearly extracted by the proposed method, which proves its validity and applicability in the analysis of seismic wave propagation in complex media. © 2017, Editorial Department OIL GEOPHYSICAL PROSPECTING. All right reserved.