Shifted first arrival point travel time NMO inversion  

平移初至点走时动校正反演(英文)

作　　者：谭尘青[1] 吴燕冈[1] 韩立国[1] 巩向博[1] 崔杰[1] 

机构地区：[1]吉林大学地球探测科学与技术学院,长春130026

出　　处：《Applied Geophysics》2011年第3期217-224,240,241,共10页应用地球物理（英文版）

基　　金：sponsored by the National Natural Science Foundation of China (No. 41074075)

摘　　要：Serious stretch appears in shallow long offsset signals after NMO correction. In this article we study the generation mechanism of NMO stretch, demonstrate that the conventional travel time equation cannot accurately describe the travel time of the samples within the same reflection wavelet. As a result, conventional NMO inversion based on the travel time of the wavelet＇s central point occurs with errors. In this article, a travel time equation for the samples within the same wavelet is reconstructed through our theoretical derivation （the shifted first arrival point travel time equation）, a new NMO inversion method based on the wavelet＇s first arrival point is proposed. While dealing with synthetic data, the semblance coefficient algorithm equation is modified so that wavelet first arrival points can be extracted. After that, NMO inversion based on the new velocity analysis is adopted on shot offset records. The precision of the results is significantly improved compared with the traditional method. Finally, the block move NMO correction based on the first arrival points travel times is adopted on long offset records and non-stretched results are achieved, which verify the proposed new equation.浅层长排列信号在动校正后出现动校拉伸,本文从走时公式的角度深入研究其产生机理,,论证了常规走时公式不能准确描述同一反射子波中所有采样点的走时,建立在子波中心点走时基础上的传统速度分析不能得到准确的动校正速度。通过理论推导重构了同一子波周期中各信号点的走时公式,进而提出基于初至点走时的动校正反演方法,其反演精度相对于传统方法得到了大幅提升。最终采用初至点走时对长排列记录进行整体搬家取得了无拉伸校平的结果,验证了所重构公式的正确性。

关 键 词：long offset NMO stretch first arrival point travel time equation NMO inversion 

分 类 号：P631[天文地球—地质矿产勘探]