Analysis of multiple-converted interference wave in seismic physical modeling data

One special interference wave frequently appears in the shot records of multi-layer seismic physical models, whose amplitude is relatively strong around the shallow interfaces. The interference wave intersects with the reflection wave events from middle and far offset and severely affects the amplitude analysis on reflection wave of seismic physical modeling data. Based on a multi-layer physical model, we use elastic wave equation forward numerical simulation to analyze the generation mechanism of the interference wave for a multi-layer numerical model with the same parameters. Then the ray tracing method is utilized to trace its propagation path and we find that it is a P-S-P multiple converted process. It was believed that the difference of the wave impedance between adjacent layers is relatively large in multi-layer physical modeling, therefore the incident P-wave can generate transmitted S-wave with stronger energy, and when the S-wave arrives at nearby interface it will induce reflected P-wave again. The amplitude of the interference wave is relatively large near shallow interfaces. In the processing of seismic physical modeling data the multiple-converted interference wave can be removed by Radon filtering. ©, 2015, Science Press. All right reserved.