3D elastic reverse time migration based on P- and S-wave decoupling

doi:10.6038/cjg2018L0247

	3D elastic reverse time migration based on P- and S-wave decoupling
	Zhou XiYan 1,2,3; Chang Xu 1,2; Wang YiBo 1,2; Yao ZhenXing 2,4
刊名	CHINESE JOURNAL OF GEOPHYSICS-CHINESE EDITION
	2018-03-01
卷号	61 期号:3 页码:1038-1052
关键词	P- and S-wave decoupling Vector-based wavefields separation 3D Poynting vector Scalar imaging condition
ISSN号	0001-5733
DOI	10.6038/cjg2018L0247
文献子类	Article
英文摘要	Elastic reverse time migration contains information of not only reflected P-wave but also converted S-waves. Converted S-waves have more information of underground, higher resolution, and wider offset. While to get clean PP and PS images, we need to separate P- and S-waves. The traditional P- and S-wave separation method is based on Helmholtz decomposition. It supposes P-waves are no rotation wavefield and S-waves are no divergence wavefield. So, P-waves are calculated by a gradient operator and S-waves calculated by a curl operator. The phase and amplitude information of decomposed waves are changed, because of a space difference operator. We adopt the P- and S-wave decoupled method to separate P- and S-waves. We extend this decoupled method to 3D media and compare with the Helmholtz decomposition method. We find this decoupled method can maintain the phase and amplitude information of separated P- and S-waves. By this decoupled method, the separated P- and S-waves both are vectors. We need to get scalar images from these vector wavefields if we want to use the decoupled method in elastic reverse time migration. We introduce Poynting vector of P- and S-waves to scalarize vector P- and S-waves. Then we use a traditional acoustic reverse time migration imaging condition to get scalar PP and PS images. These images can maintain phase and amplitude information, because we use P- and S-wave decoupled method to separate them. And the imaging results have no polarity inversal problem. But we find the Poynting vector of S-waves are inaccurate because the S-wave stress are interfered by P-waves. So, we use the S-wave quasi-stress tensor to calculate the S-wave Poynting vector. The S-wave quasi-stress are not interfered by P-waves. Finally, the S-wave Poynting vector calculated by S-wave quasi-stress will be more accurate. Numerical examples illustrate the validity of 3D P- and S-wave decoupled separation method and the accuracy of elastic reverse time migration by the Poynting vector.
WOS关键词	SCALAR IMAGING CONDITION ; FIELD SEPARATION ; SEISMIC DATA ; DECOMPOSITION ; EQUATION ; MEDIA
WOS研究方向	Geochemistry & Geophysics
语种	英语
出版者	SCIENCE PRESS
WOS记录号	WOS:000428609900020
内容类型	期刊论文
源URL	[http://ir.iggcas.ac.cn/handle/132A11/83200]
专题	中国科学院地质与地球物理研究所
通讯作者	Chang Xu
作者单位	1.Chinese Acad Sci, Inst Geol & Geophys, Key Lab Shale Gas & Geoengn, Beijing 100029, Peoples R China 2.Chinese Acad Sci, Inst Earth Sci, Beijing 100029, Peoples R China 3.Univ Chinese Acad Sci, Beijing 100049, Peoples R China 4.Chinese Acad Sci, Inst Geol & Geophys, Key Lab Earth & Planetary Phys, Beijing 100029, Peoples R China
推荐引用方式 GB/T 7714	Zhou XiYan,Chang Xu,Wang YiBo,et al. 3D elastic reverse time migration based on P- and S-wave decoupling[J]. CHINESE JOURNAL OF GEOPHYSICS-CHINESE EDITION,2018,61(3):1038-1052.
APA	Zhou XiYan,Chang Xu,Wang YiBo,&Yao ZhenXing.(2018).3D elastic reverse time migration based on P- and S-wave decoupling.CHINESE JOURNAL OF GEOPHYSICS-CHINESE EDITION,61(3),1038-1052.
MLA	Zhou XiYan,et al."3D elastic reverse time migration based on P- and S-wave decoupling".CHINESE JOURNAL OF GEOPHYSICS-CHINESE EDITION 61.3(2018):1038-1052.