基于波印廷矢量的地震波场行波分离数值模拟与逆时成像

Numerical simulation and reverse-time imaging of the seismic one-way wave field separation based on Poynting vector

地震波正演数值模拟及逆时成像是研究复杂地震波场传播规律并提高复杂构造成像精度的基础。以复杂构造理论模型为例,开展了基于波印廷矢量的地震波场行波分离数值模拟与逆时成像方法研究。研究表明:将波印廷矢量引入到复杂地震波场数值模拟与逆时成像中,对地震波正向延拓和逆时延拓的全波场均进行上行波、下行波的方向行波波场分离处理,通过基于方向行波分离的地震波数值模拟和优化地震逆时成像条件可显著改善含倾角复杂构造逆时成像效果,在成像过程中引入角度域衰减法可进一步提高成像精度。引入波印廷矢量后的逆时成像效果显著降低了成像噪声,计算过程简单、易实现,计算量小,可为复杂构造区高精度逆时成像提供技术参考。

Forward numerical simulation and reverse-time imaging of the seismic wave are the bases for studying the propagation law of the complex seismic wave field and improving the imaging precision of the complex structures.Taking the theoretical model of the complex structures as an example,the numerical simulation and reverse-time imaging method of the seismic wave field separation were studied based on Poynting vector.The research shows that the Poynting vector was introduced into the numerical simulation and reverse-time migration of the complex seismic wave field,and for the full wave field of the seismic wave forward extrapolation and reverse-time extrapolation,the up/doungoing wave fields were automatically recognized and separated;the reverse-time imaging result of the complex structures with dip angles can be significantly improved by the seismic numerical simulation based on one-way wave field separation and the optimization of the seismic reverse-time imaging conditions.In the process of imaging,the introduced angle-domain attenuation method can further improve the imaging precision.After introducing Poynting vector,the reverse-time imaging effect can significantly reduce the imaged noise,the calculation process is simple and easy to realize with small calculation cost,which can provide the technical reference for high-precision reverse-time imaging in complex structural area.