To improve the quality of seismic wave imaging in attenuated anisotropic media and achieve stable attenuation-com-pensated imaging in TTI media,we propose a least-squares reverse time migration method(Q-TTI-LSRTM)based on a vis-coacoustic TTI pure qP-wave equation.Within the least-squares migration framework,the corresponding Born modeling equa-tion,the adjoint equation,and the gradient sensitivity-kernel for the Q-TTI-LSRTM are derived.The Q-TTI-LSRTM method naturally eliminates the numerical instability caused by attenuation compensation,as the amplitude attenuation is incorporated into the adjoint equation.Additionally,the method avoids qSV-wave inferference due to the use of the viscoacoustic TTI pure qP-wave equation.It produces migration images with high resolution,fewer artifacts,and balanced amplitude by accounting for anisotropy and absorption attenuation.Finally,model tests and field data analysis confirm the feasibility and applicability of the method.The imaging results demonstrate that the Q-TTI-LSRTM can privide high-quality imaging in attenuated regions,en-hance wavenumber components,broaden frequency bandwidth,and improve the resolution and accuracy of subsurface media imaging.
关键词
衰减补偿/最小二乘逆时偏移/TTI介质/纯qP波/近似常Q模型
Key words
attenuation and compensation/least-squares reverse time migration(LSRTM)/TTI media/pure qP-wave/near-ly constant Q model
维普
万方数据