基于频散分析的偶极横波质控与校正方法研究  

Shear Slowness Quality Control and Correction Based on Dispersion Analysis

作　　者：潘卫国 刘伟男 冯进 管耀 Pan Weiguo;Liu Weinan;Feng Jin;Guan Yao(Shenzhen Branch of CNOOC Ltd.,Shenzhen Guangdong 518054,China)

机构地区：[1]中海石油(中国)有限公司深圳分公司,广东深圳518054

出　　处：《工程地球物理学报》2022年第6期851-859,共9页Chinese Journal of Engineering Geophysics

基　　金：“十三五”国家科技重大专项(编号:2016ZX05024-004);中海石油(中国)有限公司深圳分公司2022勘探项目(编号:SCKY-2022-SZ-02)。

摘　　要：声波作为测井和地震勘探联系最紧密的纽带,在储层测井评价、井震标定等方面发挥着重要作用。由于慢速地层的存在,往往需要采用偶极子声源所产生的弯曲波进行横波时差的提取,然而由于弯曲波频散现象的存在,采用传统时域方法得到的横波时差值常常偏大。针对上述问题,在时域波形有效性和完整性检查的基础上,本文提出综合频率域单深度点频散特征曲线和全井段SFA(慢度-频率相关图)的弯曲波频散现象识别和质量控制方法;同时在传统STC(时间慢度相关法)声波时差提取基础上,基于频率域的弯曲波曲线重构方法对弯曲波频散现象进行校正,得到校正后的横波时差值。结合MDT取样资料与岩石物理图版证实,采用本文方法提取的横波时差值是准确可靠的,同时AVO反演结果表明,相比于传统声波提取结果,校正后的时差值更加符合地层真实情况,为偶极声波数据的应用奠定了基础。As the closest link between well logging and seismic exploration,acoustic logging plays an important role in reservoir logging evaluation and well-seismic calibration.In the slow formation,due to the lack of monopole shear wave,the flexural wave generated by dipole sound is used to extract the shear wave time difference.However,due to the dispersion of flexural wave,and the influence of mud slowness,mud density and so on,the shear slowness obtained by traditional extraction method in time-domain is often large.To address this problem,based on the validity and integrity of the time domain waveform,this paper proposes a method for quality control and identification of flexural wave dispersion by integrating the single depth dispersion curve and the whole well SFA(slowness-frequency analysis)map in frequency domain.And the dispersion phenomenon is corrected by dispersion curve reconstruction method of frequency domain flexural wave based on the STC(slowness-time correction),and the shear slowness is obtained.The results of MDT sample data and petrophysical plates confirm the accuracy and reliability of dipole shear slowness extracted by this method.And the AVO inversion results also show that the corrected shear slowness is more in line with the real situation of the formation than the traditional method,which lays a foundation for the application of the dipole acoustic wave data.

关 键 词：弯曲波频散 频率域 横波 质控 校正 

分 类 号：P631.4[天文地球—地质矿产勘探]