Normal moveout for long offset in isotropic media using the Padé approximation

作     者：Song Han-Jie Zhang Jin-Hai Yao Zhen-Xing 宋汉杰;张金海;姚振兴

作者机构：Key Laboratory of Earth and Planetary Physics Institute of Geology and Geophysics Chinese Academy of Sciences Beijing 100029 China University of Chinese Academy of Sciences Beijing 100049 China 

出 版 物：《Applied Geophysics》 (应用地球物理（英文版）)

年 卷 期：2016年第13卷第4期

页      面：658-666,738,739页

核心收录：

学科分类：081801[工学-矿产普查与勘探] 081802[工学-地球探测与信息技术] 08[工学] 0818[工学-地质资源与地质工程] 

基　　金：supported by the National Natural Science Foundation of China(Nos.41130418 and 41374061) the National Major Project of China(No.2011ZX05008-006)and the Youth Innovation Promotion Association CAS(No.2012054) 

主　　题：Pade approximation long offset normal moveout isotropic medium 

摘      要：The nomaal moveout correction is important to long-offset observations, especially deep layers. For isotropic media, the conventional two-term approximation of the normal moveout function assumes a small offset-to-depth ratio and thus fails at large offset-to-depth ratios. We approximate the long-offset moveout using the Pade approximation. This method is superior to typical methods and flattens the seismic gathers over a wide range of offsets in multilayered media. For a four-layer model, traditional methods show traveltime errors of about 5 ms for offset-to-depth ratio of 2 and greater than 10 ms for offset-to-depth ratio of 3; in contrast, the maximum traveltime error for the [3, 3]-order Pade approximation is no more than 5 ms at offset-to-depth ratio of 3. For the Cooper Basin model, the maximum oft＇set-to-depth ratio for the [3, 3]-order Pade approximation is typically double of those in typical methods. The [7, 7]-order Pade approximation performs better than the [3.3]-order Pade armroximation.