VTI介质多参数联合走时层析成像方法  

Joint inversion of VTI parameters using nonlinear traveltime tomography

作　　者：刘玉柱[1] 王光银[1,2] 董良国[1] 杨积忠[1] 

机构地区：[1]海洋地质国家重点实验室,同济大学,上海200092 [2]中国石油川庆钻探工程有限公司地球物理勘探公司,成都610213

出　　处：《地球物理学报》2014年第10期3402-3410,共9页Chinese Journal of Geophysics

基　　金：国家自然科学基金(41274116);国家重大专项(2011ZX05005-005-007HZ);中央高校基本科研业务费专项资金(20123197);海洋地质国家重点实验室自主课题(MGG2013001)共同资助

摘　　要：本文基于球谐展开群速度表达式计算走时关于各向异性参数的Fréchet核函数,利用共轭梯度法对两种参数化方法进行了VTI介质中多参数联合反演方法研究.经过理论分析和数值试验发现,与经典的Thomsen参数化方法相比,垂直慢度、水平慢度与动校正慢度的参数化方式更有利于VTI介质多参数联合走时层析反演.为了克服走时对ε参数的不敏感性,我们采用了两步法进行双参数反演,理论模型试验反演得到了与垂直速度精度相当的ε参数.可以将两步法扩展到三步法以同时反演各向异性介质中的三个参数,数值试验展示了该策略的应用潜力.In this paper,we use a nonlinear tomographic method to jointly invert for the multiple parameters in VTI media.It is based on the harmonic series of group velocity to calculate the Fréchet kernels of traveltime with respect to model parameters.Two parameterizations are used.Through theoretically analysis and numerical experiments,we find that the parameterization of vertical slowness,horizontal slowness,and NMO slowness is more appropriate for joint traveltime tomography,compared with the traditional Thomsen parameterization.To overcome the insensitivity of traveltime to epsilon,a double-round strategy is employed in double-parameter inversion,through which epsilon as well as vertical velocity is successfully obtained.The extension from double-round to triple-round strategy also shows great potential to construct all of the three parameters.

关 键 词：VTI介质 Fréchet核函数 联合反演 敏感核函数 初至波 层析成像 

分 类 号：P631[天文地球—地质矿产勘探]