利用瑞利面波提高近地表横波速度精度的方法  

The method of enhancing the accuracy of near-surface shear wave velocity using Rayleigh waves

作　　者：西永在[1,2,3] 廖桂香 李永博[1,2,3] 吴珊 XI Yongzai;LIAO Guixiang;LI Yongbo;WU Shan(Institute of Geophysical and Geochemical Exploration,Chinese Academy of Geological Sciences,Langfang,Hebei 065000,China;Key Laboratory of Geophysical Electromagnetic Probing Technologies,Ministry of Natural Resources,Langfang,Hebei 065000,China;National Center for Geological Exploration Technology,Langfang,Hebei 065000,China)

机构地区：[1]中国地质科学院地球物理地球化学勘查研究所,河北廊坊065000 [2]自然资源部地球物理电磁法探测技术重点实验室,河北廊坊065000 [3]国家现代地质勘查工程技术研究中心,河北廊坊065000

出　　处：《石油地球物理勘探》2024年第5期957-964,共8页Oil Geophysical Prospecting

摘　　要：二维油气地震勘探中,由于受野外施工条件、成本效益等诸多因素限制,地震记录的野外采集道间距往往较大,这种地震记录往往容易产生空间假频,降低其频率—速度谱信噪比。为此,提出利用小波变换良好的时频分析特性,对大时空采样记录进行基于小波基的道内插值,以提高P-SV转换波地震资料中的瑞利面波频散高频信息的精度,从而提高反演表层横波速度结构精度,提高P-SV转换波的横波静校正精度。对理论模型和实际数据进行的验证计算表明,基于小波基的道内插值方法具有抗假频性,瑞利面波基阶频散曲线拐点更清晰,高频段能量更加集中,反演的横波速度精度更高,取得了较好效果。In two-dimensional oil and gas exploration,the wide spacing between seismic traces in field data acquisition is often constrained by factors such as field construction conditions and cost-effectiveness.Such seismic records are prone to spatial aliasing,leading to a decrease in the signal-to-noise ratio of their frequency velocity spectra.To address this issue,this paper proposes utilizing the excellent time-frequency analysis characteristics of wavelet transform to perform wavelet-based inter-traces interpolation on densely sampled records.This is done to enhance the accuracy of high-frequency information of Rayleigh surface waves in P-SV converted wave seismic data,thereby improving the accuracy of inverting near-surface shear wave velocity structures and enhancing the static correction accuracy of P-SV converted waves.Verification calculations on theoretical models and actual data demonstrate that the wavelet-based interline interpolation method exhibits anti-aliasing properties,resulting in clearer inflection points in the dispersion curves of Rayleigh surface waves and a more concentrated energy in the high-frequency range.The accuracy of the inverted shear wave velocity is higher,achieving good results.

关 键 词：大道距采样 小波变换 道内插值 瑞利面波 P-SV 利静校正 

分 类 号：P631[天文地球—地质矿产勘探]