Title

Research on sensitivity of phase velocity with respect to elastic moduli parameters in TTI media

单位

(1.东华理工大学放射性地质与勘探技术国防重点学科实验室,江西南昌330013;2.中国石油大学(北京)油气资源与探测国家重点实

验室,北京102249;3.中国石油大学(北京)CNPC物探重点实验室,北京102249)

Organization

(1.Fundamental Science on Radioactive Geology and Exploration Technology Laboratory,East China Institute of Technology,Nanchang

344000,China;2.State Key Laboratory of Petroleum Resources and Prospecting,China University of Petroleum,Beijing

102249,China;3.CNPC Key Laboratory of Geophysical Exploration,China University of Petroleum,Beijing 102249,China)

摘要

速度敏感函数是相(群)速度对各向异性介质参数的偏微分表达式,它是各向异性介质走时扰动方程的重要组成成分,所以具

有重要的研究价值。由于群速度是相速度的函数,所以利用相速度偏微分表达速度敏感函数更加简便。参考前人基于VTI介质模

型的速度敏感函数计算方法,推导出了基于TTI介质模型以相速度偏微分表达的速度敏感函数计算方法,并对VTI介质和TTI介质的

qP波、qSV波和qSH波分别模拟计算了速度敏感函数。对速度敏感函数的特性分析结果表明,不同弹性参数的速度敏感性不同,同

一弹性参数不同观测角度的速度敏感性也不同,VTI介质的速度敏感函数存在对称性,而TTI介质的速度敏感函数相对复杂得多。最

后利用TI介质反射波非线性走时反演算法对层间块状异常体模型进行了走时反演,反演结果验证了速度敏感函数计算方法的正确

性,也证实了速度敏感函数对反演结果具有预测和指示作用。

Abstract

Velocity sensitivity function is the derivatives of group velocity or phase velocity with respect to each anisotropic

parameter in anisotropic media,which is an important component in first-order traveltime perturbation equation.Therefore,it has

significant meaning for us to research the velocity sensitivity function.It is much simpler to use derivatives of phase velocity to

calculate velocity sensitivity function,because group velocity is a function of phase velocity.Some scholars have investigated velocity

sensitivity function algorithm for VTI media.The velocity sensitivity function algorithm of phase velocity was deduced for TTI media

in this article.Moreover,velocity sensitivity functions of qP,qSV and qSH waves for VTI and TTI media are calculated.Research results

prove that velocity sensitivities of different elastic parameters are different.The velocity sensitivity function is varying with

observation angle for the same elastic parameters.Velocity sensitivity function of TTI medium is much more complicated than that of

VTI medium,because the former one has symmetrical characteristics in VTI medium.Finally,we adopt traveltimes of interbedded

abnormal body model for tomography.The inversion results verify that the algorithm of velocity sensitivity function is correct and

the velocity sensitivity function plays the prediction and indication role for inversion results.

关键词：

TTI介质; 弹性模量参数; 速度敏感函数; 相速度; 走时反演;

Keywords:

TTI media; elastic moduli parameters; velocity sensitivity function; phase velocity; traveltime inversion;

基金项目

DOI

10.3969/j.issn.1000-1441.2014.03.003

TTI介质相速度对弹性模量参数的敏感性研究