Elastic reverse-time migration based on amplitude-preserving P- and S-wave separation
Yang Jia-Jia1,2, Luan Xi-Wu1,2, Fang Gang1,2, Liu Xin-Xin1,2, Pan Jun1,2, and Wang Xiao-Jie1,2
1. Key Laboratory of Marine Hydrocarbon Resources and Environmental Geology, Ministry of Land and Resources, Qingdao Institute of Marine Geology, Qingdao 266071, China;
2. Laboratory for Marine Mineral Resources, National Laboratory for Marine Science and Technology, Qingdao 266071, China.
Abstract Imaging the PP- and PS-wave for the elastic vector wave reverse-time migration requires separating the P- and S-waves during the wave field extrapolation. The amplitude and phase of the P- and S-waves are distorted when divergence and curl operators are used to separate the P- and S-waves. We present a P- and S-wave amplitude-preserving separation algorithm for the elastic wavefield extrapolation. First, we add the P-wave pressure and P-wave vibration velocity equation to the conventional elastic wave equation to decompose the P- and S-wave vectors. Then, we synthesize the scalar P- and S-wave from the vector P- and S-wave to obtain the scalar P- and S-wave. The amplitude-preserved separated P- and S-waves are imaged based on the vector wave reverse-time migration (RTM). This method ensures that the amplitude and phase of the separated P- and S-wave remain unchanged compared with the divergence and curl operators. In addition, after decomposition, the P-wave pressure and vibration velocity can be used to suppress the interlayer reflection noise and to correct the S-wave polarity. This improves the image quality of P- and S-wave in multicomponent seismic data and the true-amplitude elastic reverse time migration used in prestack inversion.
This work is supported by Special Research Grant for Non-profit Public Service (No. 201511037), National Natural Science Foundation of China (No. 41504109, 41506084, and 41406071), China Postdoctoral Science Foundation (No. 2015M582060), and Qingdao Municipal Applied Research Projects (No. 2015308).
Cite this article:
. Elastic reverse-time migration based on amplitude-preserving P- and S-wave separation[J]. APPLIED GEOPHYSICS, 2016, 13(3): 500-510.
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2016, Vol. 13 
