2‐D finite element acoustic wave modeling including rugged topography

Abstract

The problems induced by rugged topography in seismic data processing has attracted geophysicist's more and more attention in recent years. Some approaches about the S/N ratio, static correction, wave-equation datuming , stack and migration have achieved in order to attenuate the effect of the rugged surface. But there are still some problems needed to be further researched, such as seismic numerical modeling. By the means of seismic numerical modeling, we can investigate the wave generation and propagation in detail and obtain numerical seismic gathers or section for validation of seismic data processing and seismic data interpretation. In this paper, we employ the finite element method based on hybrid element technique and develop a boundary condition and a corner condition to simulate the acoustic wave propagation numerically. The hybrid element technique uses both of the triangular and rectangular elements to dissect the computational area with rugged surface and extend the mass and stiffness matrices of triangular element to those of rectangular element in form for computational unity. In order to eliminate the boundary reflection on the boundary and at corner better, we introduce a boundary condition which contains a parameter, the incident angle, and develop a corner condition which considers both of the up or down going wave and left or right going wave. Very encouraging results have been obtained on theoretical and real models .