基于小波变换的虚震源信号去噪研究
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摘要
常规地震勘探中,复杂覆盖层会降低地下深处目标层的成像效果.虚震源法将下行波与对应的上行波进行互相关运算,使地表震源重建到地下检波器的位置,由此避开构建覆盖层的速度模型,改善了地震记录的质量.然而,传统的虚震源法是在时空域中进行的,受多次波、散射波及其他噪声干扰,重建的虚震源数据质量会降低.对此,本文结合小波互相关与小波阈值去噪法,将小波变换运用在虚震源法处理过程中,在小波域里进行互相关得到虚震源信号小波系数谱,然后进行小波阈值去噪.通过模拟实验证明,与传统虚震源法相比,这种做法提高了虚震源数据的质量.
In the conventional seismic exploration, the imaging effect of the target layer is reduced by complex overburden. Virtual source method cross-correlates down-going waves with the corresponding up-going waves to reconstruct the position of surface source to the position of the buried receiver location. So this approach doesn't build the velocity model of overburden and it improves image quality. However, the traditional virtual source method, which is performed in the space-time domain, will make the quality of the reconstructed virtual source data degraded by multiple waves, scattered waves and other noise. This paper combines wavelet cross-correlation and wavelet threshold de-noising,applying wavelet transform to the process of virtual source method. The wavelet coefficients spectrums of the virtual source signal are obtained by wavelet cross-correlation. Then those spectrums are subjected to wavelet threshold de-noising. and virtual source signals are de-noised by threshold filtering in the wavelet domain. Compared with the traditional method, this method improves the quality of virtual source data.
In the conventional seismic exploration, the imaging effect of the target layer is reduced by complex overburden. Virtual source method cross-correlates down-going waves with the corresponding up-going waves to reconstruct the position of surface source to the position of the buried receiver location. So this approach doesn't build the velocity model of overburden and it improves image quality. However, the traditional virtual source method, which is performed in the space-time domain, will make the quality of the reconstructed virtual source data degraded by multiple waves, scattered waves and other noise. This paper combines wavelet cross-correlation and wavelet threshold de-noising,applying wavelet transform to the process of virtual source method. The wavelet coefficients spectrums of the virtual source signal are obtained by wavelet cross-correlation. Then those spectrums are subjected to wavelet threshold de-noising. and virtual source signals are de-noised by threshold filtering in the wavelet domain. Compared with the traditional method, this method improves the quality of virtual source data.
引文
Alexandrov D, Bakulin A, Burnstad R, et al. 2015. Improving imaging and repeatability on land using virtual source redatuming with shallow buried receivers [J]. Geophysics, 80(2): 15-26, doi: 10.1190/geo2014-0373.1.
CAI Jianhua, XIONG Rui. 2016. Magnetotelluric data denosing based on time-frequency analysis of the frequency slice wavelet transform [J]. Geophysical Prospecting for Petroleum (in Chinese), 55(6): 904-912. doi: 10.3969/j.issn.1000-1441.2016.06.016.
Calvert R W, Bakulin A, Jones T C. 2004. Virtual sources, a new way to remove overburden problems. 66th Annual International Conference and Exhibition, EAGE, Extended Abstracts, 234.
CAO Hui, CHEN Guo-jin, WU Yong-shuan, et al. 2012. Review of the seismic virtual source method [J]. Progress in Geophysics (in Chinese), 27(3): 1078-1085, doi: 10.6038/j.issn.1004-2903.2012.03.031.
LEI Chao-yang, LIU Huai-shan. 2017. Suppress of virtual source method's correlated gather noise [J]. Progress in Geophysics (in Chinese), 32(3): 1154-1160. doi:10.6038/pg20170327.
Li H, Nozaki T. 1997. Application of wavelet cross-correlation analysis to a plane turbulent jet [J]. JSME International Journal Series B, 40(1): 58-66.
Mehta K, Bakulin A, Sheiman J, et al. 2007a. Improving the virtual-source method by wavefield separation [J]. Geophysics, 72(4): 975-979.
Mehta K, Sheiman J, Snieder R, et al. 2007b. The virtual-source method applied to Mars field OBC data for time-lapse monitoring [C]. SEG Technical Program Expanded Abstracts, Society of Exploration Geophysicists, 2914-2918.
Melo G, Malcolm A, Mikessel D, et al. 2010. Using SVD for improved interferometric Green’s function recovery [C]. SEG Technical Program Expanded Abstracts, Society of Exploration Geophysicists, 3986-3990.
SHENG Nan, CHEN Guo-chu. 2016. Research and application of wavelet threshold de-noising [J]. Technology and Innovation (in Chinese), (20): 76.
Snieder R, Wapenaar K, Larner K. 2006. Spurious multiples in seismic interferometry of primaries [J]. Geophysics, 71(4): Sl111- Sl124.
Wang Z G, Gao J H, Wang P,et al. 2016. The analytic wavelet transform with generalized Morse wavelets to detect fluvial channels in the Bohai Bay Basin, China [J]. Geophysics, 81(4): O1-O9, doi: 10.1190/geo2015-0396.1.
Wang Zhi-guo, Zhang Bing, Gao Jinghuai,et al. 2017. Wavelet transform with generalized beta wavelets for seismic time-frequency analysis [J]. GEOPHYSICS, 82(4): 47-56, doi:10.1190/GEO2016-0342.1.
Wapenaar K, Fokkema J. 2006. Green’s function representations for seismic interferometry [J]. Geophysics, 71(4): Sl33- Sl46.
XU Zhuo, HAN Li-guo, WANG Li-ming. 2012. Virtual source method for detecting subsurface steep structure [J]. Global Geology (in Chinese), 31(3): 554-560.
Yang Zhao, Li Weichang. 2018. Wavelet-crosscorrelation-based interferometric redatuming in 4D seismic [J]. GEOPHYSICS, 83(4): Q37-Q47, doi: 10.1190/GEO2017-0489.1
Zhao Y, Burnstad R. 2015. A new virtual source redatuming procedure to improve land 4D repeatability, SEG Technical Program Expanded Abstracts, 5399-5403, doi:10.1190/segam2015-5865289.1.
Zhu Li-bin, MO Yan-gang, WANG Yan-chun, et al. 2017. Surface wave suppression technology based on two-dimensional wavelet transform [J]. Marine Geology Frontiers (in Chinese), 33(2): 60-64.
蔡剑华, 熊锐. 2016. 基于频率切片小波变换的时频分析与MT信号去噪[J]. 石油物探, 55(6): 904-912. doi: 10.3969/j.issn.1000-1441.2016.06.016.
曹辉, 陈国金, 吴永栓, 等. 2012. 虚源法地震技术综述[J]. 地球物理学进展, 27(3): 1078-1085, doi: 10.6038/j.issn.1004-2903.2012.03.031.
雷朝阳, 刘怀山. 2017. 虚源法相关道集噪声压制技术[J]. 地球物理学进展, 32(3): 1154-1160. doi: 10.6038/pg20170327.
盛楠, 陈国初. 2016. 小波阈值去噪的研究及应用[J]. 科技与创新, (20): 76.
许卓, 韩立国, 王立明. 2012. 虚拟震源方法用于探测地下陡倾角地质构造[J]. 世界地质, 31(3): 554-560.
朱立彬, 莫延钢, 王彦春, 等. 2017. 基于二维小波变换的面波压制技术[J]. 海洋地质前沿, 33(2): 60-64.
CAI Jianhua, XIONG Rui. 2016. Magnetotelluric data denosing based on time-frequency analysis of the frequency slice wavelet transform [J]. Geophysical Prospecting for Petroleum (in Chinese), 55(6): 904-912. doi: 10.3969/j.issn.1000-1441.2016.06.016.
Calvert R W, Bakulin A, Jones T C. 2004. Virtual sources, a new way to remove overburden problems. 66th Annual International Conference and Exhibition, EAGE, Extended Abstracts, 234.
CAO Hui, CHEN Guo-jin, WU Yong-shuan, et al. 2012. Review of the seismic virtual source method [J]. Progress in Geophysics (in Chinese), 27(3): 1078-1085, doi: 10.6038/j.issn.1004-2903.2012.03.031.
LEI Chao-yang, LIU Huai-shan. 2017. Suppress of virtual source method's correlated gather noise [J]. Progress in Geophysics (in Chinese), 32(3): 1154-1160. doi:10.6038/pg20170327.
Li H, Nozaki T. 1997. Application of wavelet cross-correlation analysis to a plane turbulent jet [J]. JSME International Journal Series B, 40(1): 58-66.
Mehta K, Bakulin A, Sheiman J, et al. 2007a. Improving the virtual-source method by wavefield separation [J]. Geophysics, 72(4): 975-979.
Mehta K, Sheiman J, Snieder R, et al. 2007b. The virtual-source method applied to Mars field OBC data for time-lapse monitoring [C]. SEG Technical Program Expanded Abstracts, Society of Exploration Geophysicists, 2914-2918.
Melo G, Malcolm A, Mikessel D, et al. 2010. Using SVD for improved interferometric Green’s function recovery [C]. SEG Technical Program Expanded Abstracts, Society of Exploration Geophysicists, 3986-3990.
SHENG Nan, CHEN Guo-chu. 2016. Research and application of wavelet threshold de-noising [J]. Technology and Innovation (in Chinese), (20): 76.
Snieder R, Wapenaar K, Larner K. 2006. Spurious multiples in seismic interferometry of primaries [J]. Geophysics, 71(4): Sl111- Sl124.
Wang Z G, Gao J H, Wang P,et al. 2016. The analytic wavelet transform with generalized Morse wavelets to detect fluvial channels in the Bohai Bay Basin, China [J]. Geophysics, 81(4): O1-O9, doi: 10.1190/geo2015-0396.1.
Wang Zhi-guo, Zhang Bing, Gao Jinghuai,et al. 2017. Wavelet transform with generalized beta wavelets for seismic time-frequency analysis [J]. GEOPHYSICS, 82(4): 47-56, doi:10.1190/GEO2016-0342.1.
Wapenaar K, Fokkema J. 2006. Green’s function representations for seismic interferometry [J]. Geophysics, 71(4): Sl33- Sl46.
XU Zhuo, HAN Li-guo, WANG Li-ming. 2012. Virtual source method for detecting subsurface steep structure [J]. Global Geology (in Chinese), 31(3): 554-560.
Yang Zhao, Li Weichang. 2018. Wavelet-crosscorrelation-based interferometric redatuming in 4D seismic [J]. GEOPHYSICS, 83(4): Q37-Q47, doi: 10.1190/GEO2017-0489.1
Zhao Y, Burnstad R. 2015. A new virtual source redatuming procedure to improve land 4D repeatability, SEG Technical Program Expanded Abstracts, 5399-5403, doi:10.1190/segam2015-5865289.1.
Zhu Li-bin, MO Yan-gang, WANG Yan-chun, et al. 2017. Surface wave suppression technology based on two-dimensional wavelet transform [J]. Marine Geology Frontiers (in Chinese), 33(2): 60-64.
蔡剑华, 熊锐. 2016. 基于频率切片小波变换的时频分析与MT信号去噪[J]. 石油物探, 55(6): 904-912. doi: 10.3969/j.issn.1000-1441.2016.06.016.
曹辉, 陈国金, 吴永栓, 等. 2012. 虚源法地震技术综述[J]. 地球物理学进展, 27(3): 1078-1085, doi: 10.6038/j.issn.1004-2903.2012.03.031.
雷朝阳, 刘怀山. 2017. 虚源法相关道集噪声压制技术[J]. 地球物理学进展, 32(3): 1154-1160. doi: 10.6038/pg20170327.
盛楠, 陈国初. 2016. 小波阈值去噪的研究及应用[J]. 科技与创新, (20): 76.
许卓, 韩立国, 王立明. 2012. 虚拟震源方法用于探测地下陡倾角地质构造[J]. 世界地质, 31(3): 554-560.
朱立彬, 莫延钢, 王彦春, 等. 2017. 基于二维小波变换的面波压制技术[J]. 海洋地质前沿, 33(2): 60-64.