复杂地表的单程波动方程地震叠前正演
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摘要
基于数学检波器和等时叠加原理,实现了复杂地表的单程波动方程地震叠前正演模拟。该方法采用虚拟的数学检波器接收地下反射地震信号,可灵活地将接收点布置在地表的任何地方,从而满足地表起伏的要求。此外,根据等时叠加原理,该方法采用单程波动方程进行波场延拓和成像,计算简单、快速。通过复杂正断层的数值模拟,得到了高信噪比的共炮地震记录;采用适用于起伏地形的深度偏移方法对该共炮记录进行了叠前深度偏移,实现了地震波的偏移归位。从而证明了本文提出的适用于起伏地表的单程波动方程地震叠前正演方法的正确性和准确性。
Mathematical geophone and equal-time stacking principle are proposed in this paper, based on which, we can do seismic prestack forward modeling from irregular surfaces with one-way acoustic wave equation. By employing the mathematical geophone, receiver points can be located at anywhere of the surfaces. According to the equal-time stacking principle, we can easily imagingreflected seismic wave-field with one-way acoustic wave equation. To test the prestack forward modeling method, firstly compare the difference of common-shot records between flat and irregular surfaces, then design a complex normal fault model and generate its corresponding common-shot records. The result of depth migration directly from the irregular surface illustrates the method is correct and accurate.
Mathematical geophone and equal-time stacking principle are proposed in this paper, based on which, we can do seismic prestack forward modeling from irregular surfaces with one-way acoustic wave equation. By employing the mathematical geophone, receiver points can be located at anywhere of the surfaces. According to the equal-time stacking principle, we can easily imagingreflected seismic wave-field with one-way acoustic wave equation. To test the prestack forward modeling method, firstly compare the difference of common-shot records between flat and irregular surfaces, then design a complex normal fault model and generate its corresponding common-shot records. The result of depth migration directly from the irregular surface illustrates the method is correct and accurate.
引文
[1]贺振华.反射地震资料偏移处理与反演方法.重庆:重庆大学出版社,1989
[2]Moshe Reshef.Depth migration from irregular surfaces with depth extrapolation methods.Geophysics,1991,56:119￣122
[3]褚春雷,王修田.非规则三角网格有限差分法地震正演模拟.中国海洋大学学报,2005,35(1):43￣48
[4]He Zhenhua,Xiong Gaojun,Zhang Yixiang.Nonzero offset Seismic Forward Modeling By one-way Acoustic Wave-equation:68th Ann.Internat.Mtg.,Soc.Expl.Geophys.,Expanded Abstracts,1998:1921￣1924
[5]Stig Hestholm.Elastic wave modeling with free surfaces:Stability of long simulations.Geophysics,2003,68:31￣321
[6]Craig Beasley,Walt Lynn.The zero-velocity layer.Migration from irregular surfaces.Geophysics,1992,57:1435￣1443
[2]Moshe Reshef.Depth migration from irregular surfaces with depth extrapolation methods.Geophysics,1991,56:119￣122
[3]褚春雷,王修田.非规则三角网格有限差分法地震正演模拟.中国海洋大学学报,2005,35(1):43￣48
[4]He Zhenhua,Xiong Gaojun,Zhang Yixiang.Nonzero offset Seismic Forward Modeling By one-way Acoustic Wave-equation:68th Ann.Internat.Mtg.,Soc.Expl.Geophys.,Expanded Abstracts,1998:1921￣1924
[5]Stig Hestholm.Elastic wave modeling with free surfaces:Stability of long simulations.Geophysics,2003,68:31￣321
[6]Craig Beasley,Walt Lynn.The zero-velocity layer.Migration from irregular surfaces.Geophysics,1992,57:1435￣1443
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