芦俊^1,,
石瑛^1,,,
杨春颖²
1. 中国地质大学(北京)能源学院, 海相储层演化与油气富集机理教育部重点实验室, 北京 100083
2. 中国地质大学(北京)地球物理与信息技术学院, 北京 100083

基金项目: 国家自然科学基金项目（41574126，41425017，41604119），中国国家留学基金（201606405010），中央高校基本科研业务费专项资金（2-9-2017-452）资助


详细信息

作者简介: 芦俊, 男, 副教授, 现从事多分量地震技术的研究.E-mail:lujun615@163.com

通讯作者: 石瑛, 女, 博士后, 现从事多分量地震解释的研究.E-mail:quartzsy@163.com

中图分类号: P631

收稿日期:2018-01-16
修回日期:2018-03-06
上线日期:2018-08-05

Vector wave separation in anisotropic media and its application

LU Jun^1,,
SHI Ying^1,,,
YANG ChunYing²
1. School of Energy Resources, Key Laboratory of Marine Reservoir Evolution and Hydrocarbon Accumulation Mechanism, Ministry of Education, China University of Geosciences, Beijing 100083, China
2. School of Geophysics and Information Technology, China University of Geosciences, Beijing 100083, China


More Information

Corresponding author: SHI Ying,E-mail:quartzsy@163.com

MSC: P631

--> Received Date: 16 January 2018
Revised Date: 06 March 2018
Available Online: 05 August 2018


摘要
摘要:针对裂缝各向异性介质，本文提出一种非正交假设下的矢量波场分离方法.本文首先对多分量地震勘探中常见的波型泄漏现象进行了数学描述，提出在纵、横波波场分离的同时应该考虑恢复纵、横波的矢量振幅.为了对裂缝方位角与各向异性系数进行定量预测，本文将矢量波场分离拆分成三个步骤来实施：第一步，用Z、R两分量的仿射坐标系变换分离ZR平面内的P波投影与SV波；第二步，用ZR平面内的P波投影与T分量的仿射坐标系变换分离P波与SH波；第三步，用纯净的SV波与SH波的成像剖面分离快慢横波，并预测裂缝发育参数.模型数据与实际数据的试验结果表明，本文提出的纵、横波波场分离方法能够获得完整的矢量振幅信息，并提供裂缝预测的精度.
关键词: 多分量/
仿射坐标系/
各向异性/
矢量波场分离/
裂缝预测

Abstract:For anisotropic media induced by cracks, mode leakage is one of the key issues severely affecting the multi-component data processing. Moreover, mode leakage can reduce the precision of the subsequent crack prediction. In this paper, we present a detailed description on the mathematical mechanism of the model leakage phenomenon and propose a new wave separation method.
In our method, we consider separating anisotropic wavefields in three steps. First, we perform affine coordinate system transformation to Z-and R-component records for deriving P-wave projection in ZR plane and pure SV-wave. Second, we perform affine coordinate system transformation to P-wave projection in ZR plane and T-component for deriving pure P-wave and SH-wave. Thus, we can migrate SV-and SH-waves for the subsequent poststack crack prediction. Or, we can directly use pure prestack SV-and SH-waves to separate S1-and S2-waves in the case of high signal-to-noise ratio. Thirdly, we use Alford rotation to accurately predict crack parameters by separating S1-and S2-waves based on poststack section.
We test our method using both synthetic and field three-component data. In the numerical experiment, we design a horizontal strata model, where cracks develop in the upper stratum. Our wave separation method is proved to be effective and we derive high-quality PP-, PS1-and PS2-waves using three-component synthetic shot records. In application to the field data, we compare all the results from wave separation, which reveal that mode leakage is severe in field three-component records although they are hardly to be identified only using the naked eye to observe. At last, we derive accurate crack prediction results due to our wave separation method.
Key words:Multi-component/
Affine coordinate system/
Anisotropy/
Vector wave separation/
Crack prediction



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