Love wave full waveform inversion via Pseudo-Hessian gradient pre-conditioning operator
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摘要: 构建近地表横波速度模型是煤田多分量地震资料处理的重要环节。相较于面波多道分析法,全波形反演在构建近地表横波模型中具有更高的分辨率。然而,在基于梯度的全波形反演中,由于地震记录频带有限、波场的非均匀覆盖以及双重散射等原因导致梯度算子不随深度的增加而缩放,模型深部参数得不到明显更新。目标函数的Hessian算子包含曲率信息,可清晰预测梯度算子中的焦散现象及双重散射产生的伪影,因此,逆Hessian算子则可作为反卷积算子实现对梯度的预处理,加强对模型深部的照明能力。然而Hessian算子具有巨大维度,对其显式计算十分困难。基于此,借鉴逆散射理论的思想,给出勒夫波全波形反演目标函数的拟Hessian算子的表达式,并提出一种梯度预处理的全波形反演方法。将该方法分别应用于断层模型、凹陷模型以及起伏界面模型的重构试验,反演结果表明:与传统的共轭梯度全波形反演方法相比,基于拟Hessian算子的预处理共轭梯度方法可加快收敛速度,提升成像质量。Abstract: The construction of near surface shear wave velocity is an important step in multi-component seismic data processing in coalfield. Compared with the multichannel analysis of surface wave, the full waveform inversion(FWI) has higher resolution in the construction of near surface shear wave velocity model. However, in the gradient-based FWI, the gradient operator is not scaled with increasing depth due to the narrow frequency band of seismic records, the non-uniform coverage of the wavefield, and the double scattering. The parameters of the deep model cannot be updated significantly. The Hessen operator of the objective function contains curvature information, which can clearly predict the defocusing phenomenon and the artifacts generated by double scattering in the gradient operator. The inverse Hessen operator can be used as a deconvolution operator to realize gradient pre-conditioning and enhance the illumination ability of the deep model. However, the explicit calculation of Hessian operator is very difficult because it has huge dimensions. Based on this, inverse scattering theory is referred to, the expression of the pseudo-Hessian operator of the objective function of full-waveform inversion is given, and a pre-conditioned gradient-based FWI method is developed. The proposed method was applied to the reconstruction tests of the fault model, subsidence model, and undulating interface model, respectively. The inversion results show that, compared with the classic conjugate gradient-based FWI, the pre-conditioned conjugate gradient method based on the pseudo-Hessian operator can accelerate the convergence rate and improve the inversion accuracy.
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表 1 断层模型重构测试中PCG与CG算法的性能对比评价
Table 1 Comparison and evaluation of the PCG and CG algorithms in fault model reconstruction test
寻优算法 迭代次数 归一化目标函数终值 模型对比误差初值 模型对比误差终值 CG 39 0.026 6 0.080 1 0.047 2 PCG 17 0.011 6 0.080 1 0.022 9 表 2 凹陷模型重构测试中PCG与CG算法性能对比评价
Table 2 Comparison and evaluation of the PCG and CG algorithms in subsidence model reconstruction test
寻优算法 迭代次数 归一化目标函数终值 模型对比误差初值 模型对比误差终值 CG 40 0.052 1 0.102 8 0.088 7 PCG 40 0.005 8 0.102 8 0.030 6 表 3 界面起伏模型重构测试中PCG与CG算法性能对比评价
Table 3 Comparison and evaluation of the PCG and CG algorithms in undulating interface model reconstruction test
寻优算法 迭代次数 归一化目标函数终值 模型对比误差初值 模型对比误差终值 CG 21 0.117 3 0.089 3 0.081 2 PCG 19 0.011 5 0.089 3 0.078 5 表 4 PBGJ-PCG与PCG算法性能对比评价
Table 4 Comparison and evaluation of the PBGJ-PCG and PCG algorithms
寻优算法 迭代次数 归一化目标函数终值 模型对比误差初值 模型对比误差终值 PCG 19 0.011 5 0.089 3 0.078 5 PBGJ-PCG 40 0.004 8 0.089 3 0.033 4 -
[1] 张胤彬, 潘冬明, 胡明顺, 等. 复杂地表初至层析地震静校正技术及其应用[J]. 煤田地质与勘探, 2012, 40(4): 66-70.. doi: 10.3969/j.issn.1001-1986.2012.04.016ZHANG Yinbin, PAN Dongming, HU Mingshun, et al. Research and application of first arrival tomographic static technique in complex surface area[J]. Coal Geology & Exploration, 2012, 40(4): 66-70.. doi: 10.3969/j.issn.1001-1986.2012.04.016 [2] 周俊杰, 王雨, 侯玮. 黄土塬地区煤田三维地震综合处理技术[J]. 地球物理学进展, 2016, 31(5): 2299-2305. https://www.cnki.com.cn/Article/CJFDTOTAL-DQWJ201605057.htmZHOU Junjie, WANG Yu, HOU Wei. 3D seismic comprehensive processing technology of coalfield in loess tableland[J]. Progress in Geophysics, 2016, 31(5): 2299-2305. https://www.cnki.com.cn/Article/CJFDTOTAL-DQWJ201605057.htm [3] PARK C B, MILLER R D, XIA Jianghai. Multichannel analysis of surface waves[J]. Leading Edge, 1999, 18(3): 800-808. [4] XIA Jianghai, XU Yixian, LUO Yinhe, et al. Advantages of using multichannel analysis of Love waves(MALW) to estimate near-surface shear-wave velocity[J]. Surveys in Geophysics, 2012, 33(5): 841-860.. doi: 10.1007/s10712-012-9174-2 [5] 孟小红, 郭良辉. 利用地震瑞利波速度反演求取P-SV波横波静校正量[J]. 石油地球物理勘探, 2007, 42(4): 448-453.. doi: 10.3321/j.issn:1000-7210.2007.04.017MENG Xiaohong, GUO Lianghui. Using velocity inversion of seismic Rayleigh wave to compute S-wave statics of P-SV wave[J]. Oil Geophysical Prospecting, 2007, 42(4): 448-453.. doi: 10.3321/j.issn:1000-7210.2007.04.017 [6] BIONDI B, SYMES W W. Angle-domain common-image gathers for migration velocity analysis by wavefield-continuation imaging[J]. Geophysics, 2004, 69(5): 1283-1298.. doi: 10.1190/1.1801945 [7] ZHU Xianhuai, MCMECHAN G A. Estimation of a two-dimensional seismic compressional-wave velocity distribution by iterative tomographic imaging[J]. International Journal of Imaging Systems and Technology, 1989, l(1): 13-17. doi: 10.1002/ima.1850010103 [8] ZHANG Jianzhong, SHI Taikun, ZHAO Yasheng, et al. Static corrections in mountainous areas using Fresnel-wavepath tomography[J]. Journal of Applied Geophysics, 2014, 111: 242-249.. doi: 10.1016/j.jappgeo.2014.10.006 [9] TARANTOLA A. Inversion of seismic reflection data in the acoustic approximation[J]. Geophysics, 1984, 49(8): 1259-1266.. doi: 10.1190/1.1441754 [10] TARANTOLA A. A strategy for nonlinear elastic inversion of seismic reflection data[J]. Geophysics, 1986, 51(10): 1893-1903.. doi: 10.1190/1.1442046 [11] MÉTIVIER L, BROSSIER R, VIRIEUX J, et al. The truncated Newton method for full waveform inversion[C]//Las Vegas: SEG Annual Meeting, 2012. [12] MÉTIVIER L, BROSSIER R, VIRIEUX J, et al. Full waveform inversion and the truncated Newton method[J]. SIAM Journal on Scientific Computing, 2013, 35(2): B401-B437.. doi: 10.1137/120877854 [13] MÉTIVIER L, BRETAUDEAU F, BROSSIER R, et al. Full waveform inversion and the truncated Newton: Quantitative imaging of complex subsurface structures[J]. Geophysical Prospecting, 2014, 62(6): 1353-1375.. doi: 10.1111/1365-2478.12136 [14] 夏江海. 高频面波方法[M]. 武汉: 中国地质大学出版社, 2015.XIA Jianghai. High frequency surface wave method[M]. Wuhan: China University of Geosciences Press, 2015. [15] ESLICK R, TSOFLIAS G, STEEPLES D. Field investigation of Love waves in near-surface seismology[J]. Geophysics, 2008, 73(3): 1-6. http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=SEGEAB000026000001001217000001&idtype=cvips&gifs=Yes [16] PAN Yudi, XIA Jianghai, XU Yixian, et al. Love-wave waveform inversion in time domain for shallow shear-wave velocity[J]. Geophysics, 2015, 81(1): 1-14. http://adsabs.harvard.edu/abs/2016Geop...81R...1P [17] DOKTER E, KOHN D, WILKEN D, et al. Full waveform inversion of SH- and Love-wave data in near-surface prospecting[J]. Geophysical Prospecting, 2017, 65(Sup. 1): 216-236. doi: 10.1111/1365-2478.12549 [18] PLESSIX R E. A review of the adjoint-state method for computing the gradient of a functional with geophysical applications[J]. Geophysical Journal International, 2006, 167(2): 495-503.. doi: 10.1111/j.1365-246X.2006.02978.x [19] GAUTHIER O, VIRIEUX J, TARANTOLA Albert. Two-dimensional nonlinear inversion of seismic waveforms: Numerical results[J]. Geophysics, 1986, 51(7): 1387-1403.. doi: 10.1190/1.1442188 [20] PRATT R G, SHIN C, HICKS G J. Gauss-Newton and full Newton methods in frequency-space seismic waveform inversion[J]. Geophysical Journal International, 1998, 133: 341-362.. doi: 10.1046/j.1365-246X.1998.00498.x [21] SHIN C, JANG S, MIN D J. Improved amplitude preservation for prestack depth migration by inverse scattering theory[J]. Geophysical Prospecting, 2001, 49: 592-606.. doi: 10.1046/j.1365-2478.2001.00279.x [22] SHEEN D H, TUNCAY K, BAAG C E, et al. Time domain Gauss: Newton seismic waveform inversion in elastic media[J]. Geophysical Journal International, 2006, 167(3): 1373-1384.. doi: 10.1111/j.1365-246X.2006.03162.x [23] BROSSIER R, OPERTO S, VIRIEUX J. Seismic imaging of complex on shore structures by 2D elastic frequency-domain full-waveform inversion[J]. Geophysics, 2009, 74: 63-76. http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=GPYSA7000074000006WCC105000001&idtype=cvips&gifs=Yes [24] RAO Ying, WANG Yanghua, HAN Dehao. Seismic waveform tomography with simplified restarting scheme[J]. IEEE Geoscience and Remote Sensing Letters, 2018, 16(1): 135-139. http://it.ckcest.cn/portal.php?mod=viewaid=3338529 [25] 刘璐, 刘洪, 张衡, 等. 基于修正拟牛顿公式的全波形反演[J]. 地球物理学报, 2013, 56(7): 2447-2451. https://www.cnki.com.cn/Article/CJFDTOTAL-DQWX201307029.htmLIU Lu, LIU Hong, ZHANG Heng, et al. Full waveform inversion based on modified quasi-Newton equation[J]. Chinese Journal of Geophysics, 2013, 56(7): 2447-2451. https://www.cnki.com.cn/Article/CJFDTOTAL-DQWX201307029.htm [26] LI Jing, HANAFY S, LIU Zhaolun, et al. Wave equation dispersion inversion of love waves[J]. Geophysics, 2019, 84(5): 693-705.. doi: 10.1190/geo2018-0039.1 [27] LIU Zhaolun, LI Jing, HANAFY S M, et al. 3D wave-equation dispersion inversion of Rayleigh waves[J]. Geophysics, 2019, 84(5): 673-691.. doi: 10.1190/geo2018-0543.1 [28] YAN Yingwei, WANG Zhejiang, LI Jing, et al. A preconditioned technique for SH- and Love-wave full-waveform inversion in time domain and crosstalk analysis[J]. Journal of Geophysics and Engineering, 2019, 17(1): 160-174. http://www.researchgate.net/publication/337456279_A_preconditioned_technique_for_SH-_and_Love-wave_full-waveform_inversion_in_time_domain_and_crosstalk_analysis [29] YAN Yingwei, WANG Zhejiang, LI Jing, et al. Elastic SH- and Love-wave Full-Waveform Inversion for shallow shear wave velocity with a pre-conditioned technique[J]. Journal of Applied Geophysics, 2020, 173(2): 103947. http://www.sciencedirect.com/science/article/pii/S0926985118309972 [30] 闫英伟. 浅地表高频面波成像技术研究[D]. 长春: 吉林大学, 2019.YAN Yingwei. Resear on high-frequency surface wave imaging technique for the shallow subsurface[D]. Changchun: Jilin University, 2019. [31] VIRIEUX J. SH wave propagation in heterogeneous media: Velocity stress finit-difference method[J]. Geophysics, 1984, 49: 1933-1942.. doi: 10.1190/1.1441605 [32] GRAVES R W. Simulating seismic wave propagation in 3D elastic media using staggered-grid finite differences[J]. Bulletin of the Seismological Society of America, 1996, 86(4): 1091-1106. http://gji.oxfordjournals.org/cgi/ijlink?linkType=ABST&journalCode=ssabull&resid=86/4/1091 [33] MEZA-FAJARDO K C, PAPAGEPRGIOS A S. A nonconvalutional, spllit-field, perfectly matched layer for wave propagation in isotropic and anisotropic elastic media: Stability analysis[J]. Bulletin of Seismological Society of America, 2008, 98(4): 1811-1836.. doi: 10.1785/0120070223 [34] RODI W, MACKIE R L. Nonlinear conjugate gradients algorithm for 2-D magnetotelluric inversion[J]. Geophysics, 2001, 66(1): 174-187.. doi: 10.1190/1.1444893 [35] 刘聪, 王者江, 闫英伟. 基于伴随状态法二维时间域勒夫波全波形反演研究[J]. 地球物理学进展, 2019, 34(1): 136-143. https://www.cnki.com.cn/Article/CJFDTOTAL-DQWJ201901018.htmLIU Cong, WANG Zhejiang, YAN Yingwei. Research on two-dimensional Love-wave full waveform inversion in time domain based on adjoint state method[J]. Progress in Geophysics, 2019, 34(1): 136-143. https://www.cnki.com.cn/Article/CJFDTOTAL-DQWJ201901018.htm [36] GILBERT J C, NOCEDAL J. Global convergence properties of conjugate gradient methods for optimization[J]. Siam Journal on Optimization, 1992, 2(1): 21-42.. doi: 10.1137/0802003 [37] CASTELLANOS C, ETIENNE V, HU Guanghui, et al. Algorithmic and methodological developments towards full waveform inversion in 3D elastic media[C]//San Antonio: SEG [38] MORA P. Nonlinear two-dimensional elastic inversion of multioffset seismic data[J]. Geophysics, 1987, 52(9): 1211-1228.. doi: 10.1190/1.1442384