高阶弹性波数值模拟及逆时偏移成像研究

High-order elastic wave numerical simulation and reverse time migration imaging research

利用地震波在地质体中的传播为地质体建立模型,得到地震波的传播规律和变化特征,以达到探测地球深部的目的。在前人研究的基础上,使用交错网格高阶有限差分法对几种典型的地质构造模型进行地震波数值模拟,得到各模型观测的地震记录以及去除直达波和分界面反射波后的地震记录图,再使用叠前逆时偏移成像对数值模拟结果进行成像处理,实现对不同散射体和地质构造的复原。偏移结果很好地反映了地下构造形态,能够使地表接收到的波场准确归位,提高资料处理的精度。

The propagation of seismic waves in the geological body is used to establish a model for the geological body,and the propagation regularity and variation characteristics of seismic wave are obtained for the achievement of the purpose to detect the deep part of the earth.On the basis of the previous study result,the staggered grid high order finite difference method is used in the seismic wave numerical simulation of several typical models of geological structures.The seismic records observed by each model and the seismic records after removing the direct wave and the reflected wave at the interface are obtained.Then the pre-stack reverse time migration imaging data are used to image the numerical simulation result to achieve the restoration of different scatterers and geological structures.The migration result reflects the underground structure morphology well,which can accurately return the wave field received on the surface and improve the accuracy of data processing.