波动方程双向照明优化的全波形反演

Full waveform inversion with wave equation bi-directional illumination optimization

利用照明分析研究震源激发产生的地震波在地下介质中传播的能量分布情况,可以优化观测系统,使介质中的能量分布达到最优,同时可以进行能量补偿,这样就可以解决全波形反演过程中深层反演效果差的问题.基于声波方程的双向照明分析,和全波形反演建立在统一的波动方程理论框架下,相比较于射线照明来说,能更准确的描述复杂地下介质中的能量分布.因此,本文发展了一种基于波动方程双向照明优化的时域全波形反演方法,利用波动方程双向照明分析进行观测系统优化设计,得到优化后的观测系统和照明能量用于时域全波形反演中,可以达到更好的反演效果.通过模型试算证明了本方法的有效性.

Using seismic illumination analysis, we can study the seismic wave energy distribution and design effective observation system for migration or full waveform inversion. Meanwhile, we can compensate seismic energy using illumination intensity. This method can solve the difficulty that the deep area inversion effect is poor in the full waveform inversion. Compared with conventional illumination analysis, Wave equation bi-directional illumination method can provide more accurate wave-field and illumination energy especially for complex model. In this paper, we present a full waveform inversion method in time domain with wave equation illumination optimization. Firstly, we optimize the design of geometry and get the energy to compensate the deep region using illumination analysis, and then invert the velocity model by waveform inversion method. Numerical results on Marmousi model show that this method is effective and feasible.