摘要
转换点位置的计算是转换波资料处理中的一个关键问题.本文提出了分别基于速度随深度线性变化、速度随垂直走时线性变化、慢度随深度线性变化和慢度随垂直走时线性变化四种等效垂向非均匀介质情况下转换点位置的计算方法.研究了通过速度拟合、走时近似和相似系数谱三种方式选择合适的等效速度方法.结合理论模型对非均匀介质转换点计算方法、渐进转换点计算方法、Thomsen近似公式和均匀介质解析计算方法的误差进行了分析,结果表明非均匀介质转换点计算方法能更准确地计算转换点位置.
Calculating conversion points is a key problem in converted wave data processing. Here we introduce the methods to compute conversion points in vertical inhomogeneous media based on linear functions of velocity or slowness changing with depth or vertical travel times. We also study three ways to choose appropriate equivalent velocity methods, which are velocity fitting, travel time approximation and semblance coefficient methods. We compare the errors by the methods in vertical inhomogeneous media with asymptotic conversion points, Thomsen approximate formula and analytic formula in homogeneous media. The results show that conversion points can be calculated more accurately by the proposed methods for inhomogeneous media.
出处
《地球物理学报》
SCIE
EI
CAS
CSCD
北大核心
2007年第4期1225-1231,共7页
Chinese Journal of Geophysics
基金
国家重点基础研究发展计划项目(2005CB422104)
中国石油化工股份有限公司科技开发项目(P05063)联合资助.
关键词
转换点
转换波
非均匀介质
走时近似
相似系数
Conversion point, Converted wave, Inhomogeneous media, Travel time approximation, Semblance coefficient
