Attenuating Crosstalk Noise of Simultaneous-Source Least-Squares Reverse Time Migration With GPU-Based Excitation Amplitude Imaging Condition

2019 ◽  
Vol 57 (1) ◽  
pp. 587-597 ◽  
Author(s):  
Qingchen Zhang ◽  
Weijian Mao ◽  
Yangkang Chen
Geophysics ◽  
2016 ◽  
Vol 81 (1) ◽  
pp. S11-S20 ◽  
Author(s):  
Zhiguang Xue ◽  
Yangkang Chen ◽  
Sergey Fomel ◽  
Junzhe Sun

Simultaneous-source acquisition improves the efficiency of the seismic data acquisition process. However, direct imaging of simultaneous-source data may introduce crosstalk artifacts in the final image. Likewise, direct imaging of incomplete data avoids the step of data reconstruction, but it can suffer from migration artifacts. We have proposed to incorporate shaping regularization into least-squares reverse time migration (LSRTM) and use it for suppressing interference noise caused by simultaneous-source data or migration artifacts caused by incomplete data. To implement LSRTM, we have applied lowrank one-step reverse time migration and its adjoint iteratively in the conjugate-gradient algorithm to minimize the data misfit. A shaping operator imposing structure constraints on the estimated model was applied at each iteration. We constructed the shaping operator as a structure-enhancing filtering to attenuate migration artifacts and crosstalk noise while preserving structural information. We have carried out numerical tests on synthetic models in which the proposed method exhibited a fast convergence rate and was effective in attenuating migration artifacts and crosstalk noise.


Geophysics ◽  
2020 ◽  
Vol 85 (6) ◽  
pp. S405-S416
Author(s):  
Xiaofeng Jia ◽  
Wenyang Chen ◽  
Bin Chen

Reverse time migration (RTM) is a powerful seismic imaging tool that suffers from high computational complexity when dealing with massive data. The simultaneous-shot method can effectively reduce the amount of migration by assembling several sources, although it adds crosstalk noise, which seriously affects the quality of the RTM results. To avoid this problem, we have adopted a time-domain scheme that combines time-delay encoding and amplitude encoding to reduce crosstalk artifacts in simultaneous-source imaging results. This scheme modulates the wavefields of multiple sources to fit the wavefield of a suspended super-virtual shot (SVS), which can eliminate crosstalk artifacts because they are absent in single SVS migration. Numerical examples on a steeply dipping model and the 2D SEG/EAGE salt model show the feasibility of the proposed method. SVS encoding can generate a qualified imaging result and takes less time than plane-wave encoding in the migration process.


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