地球物理学进展 ›› 2018, Vol. 33 ›› Issue (5): 2056-2063.doi: 10.6038/pg2018BB0368

• 应用地球物理学Ⅰ(油气及金属矿产地球物理勘探) • 上一篇    下一篇

基于多分量地震记录的转换横波速度分析

郁建芳1(),徐浩2,*(),谢石文1,黄显良1,隆爱军1,张炳1,韩成成1   

  1. 1. 安徽省地震局,合肥 230031
    2. 中国地质大学地球物理与空间信息学院,武汉 430074
  • 收稿日期:2017-12-11 修回日期:2018-07-09 出版日期:2018-10-20 发布日期:2019-01-11
  • 通讯作者: 徐浩 E-mail:zhimeigui2009@126.com;xuhao33011@163.com
  • 作者简介:郁建芳,女,1987年生,湖北襄阳人,中国地质大学(武汉)硕士研究生,工程师,主要从事地震定位和地震波应用理论研究等工作.
  • 基金资助:
    安徽大别山地区地震监测预警项目(2016080802D117);安徽省地震科研基金青年项目(20170612);中国地震局监测司地震监测预报经常性项目(17A13ZX046)

Converted S-wave velocity analysis based on multi-component seismic records

YU Jian-fang1(),XU Hao2,*(),XIE Shi-wen1,HUANG Xian-liang1,LONG Ai-jun1,ZHANG Bing1,HAN Cheng-cheng1   

  1. 1. Earthquake Administration of Anhui Province, Hefei 230031, China
    2. Institute of Geophysics and Geomatics, China University of Geosciences, Wuhan 430074, China
  • Received:2017-12-11 Revised:2018-07-09 Online:2018-10-20 Published:2019-01-11
  • Contact: Hao XU E-mail:zhimeigui2009@126.com;xuhao33011@163.com

摘要:

转换波中既包含纵波信息也包含横波信息,其中横波信息是通过对多分量地震记录开展转换波速度分析获取得到的,通过对地震纵横波信息的联合解释能够获悉更多地下地质构造信息.本文详细阐述了转换横波速度分析方法,并将其应用到数值模拟得到的多分量地震记录中,分别在XZ分量记录上进行纵波和横波速度分析以及横纵波速度比谱扫描并对其结果进行系统分析,所得速度扫描值和理论值之间的误差均较小,以转换波时间为坐标时两者之间的最大误差为2.5%,以横波时间为坐标时误差最大为2.8%.然后分别针对坐标为转换波时间和横波时间的横波速度谱进行动校正和叠加处理,得到相应的叠加剖面,论证了基于多分量地震记录进行转换波速度分析的可行性和有效性.最后将转换波速度分析方法应用到实际某油田的多分量地震记录上,基于纵/横波速度谱进行纵波和转换横波的层位对比,结果表明纵波和横波速度谱的层位具有一致性.

关键词: 多分量地震记录, 转换波, 速度分析, 速度谱, 动校正, 叠加

Abstract:

The converted wave contains both P-wave information and S-wave information which is obtained by the velocity analysis of converted wave to the multi-component seismic records. And we can learn more about the underground geological structure through the joint interpretation of the seismic wave. This paper has described the analysis method of converted wave velocity in details, and the method is applied to the multi-component seismic records obtained by numerical simulation. The effects of P-wave velocity analysis, S/P-wave velocity ratio spectrum scanning and S-wave velocity analysis on the X-component and Z-component have been analyzed systematically. According to the results, the error of scanning velocity and theory velocity are small, it is 2.5% when the velocity analysis results marked with converted-wave time, and it is 2.8% when marked with S-wave time. So the results show that the velocity analysis results gained by the method in this paper have reached higher precision. Then we have gotten the stacked section marked separately by the time of converted-wave and S-wave from the S-wave velocity spectrum which is dealt with NMO correction and stacking. The obtained stacked section with better quality can demonstrate the feasibility and effectiveness of the converted-wave velocity analysis method on multi-component seismic records. Finally, the converted wave velocity analysis method has been applied to the actual multi-component seismic records of an oil field, horizon contrast between P-wave and converted S-wave based on the P/S velocity spectrum and the time conversion between P-wave and converted wave by velocity ratio show that the converted-wave time of the forth layer is 3.795 s. And this time point is identical with the event of strong energy around 3.8 s in the X-component seismic record. In addition, two energy groups of higher energy are distributed in the shallow and deep layers respectively of velocity ratio spectrum and S-wave velocity spectrum, and their time points coincide. These comparative interpretation results show that the horizon of P-wave and S-wave velocity spectrum are consistent.

Key words: multi-component seismic records, converted wave, velocity analysis, velocity spectrum, NMO(Normal Moveout), stacking

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