Joint interferometric imaging of walkaway VSP data  

Walkaway VSP数据的联合相干成像(英文)

作　　者：王保利[1] 朱光明[2] 高静怀[1] 

机构地区：[1]西安交通大学电子与信息工程学院波动与信息研究所,陕西西安710049 [2]长安大学地质工程与测绘学院,陕西西安710054

出　　处：《Applied Geophysics》2010年第1期41-48,99,共9页应用地球物理（英文版）

基　　金：supported by the National 863 Program of China (Grant No.2006A09A102-11);National Natural Science Foundation of China (Grant No.40730424);Important National Science & Technology Specific Projects (Grant No.2008ZX05023-005)

摘　　要：In this paper,we image the subsurface reflectors by interferometric imaging using primary and downgoing first-order free-surface related multiple reflections in walkaway VSP data.By analyzing the stack fold distribution,we find that primary-direct interferometric imaging has a smaller image range,but its stack fold is higher near the well while ghostdirect interferometric imaging is the opposite.We try to solve this problem by the joint interferometric imaging of walkaway VSP data,combining primary-direct interferometric imaging with ghost-direct interferometric imaging.In this way,we can effectively widen the imaging range,simultaneously increase the fold（especially near the well）,suppress spurious interference,and improve the image SNR,so that we can get a more credible image.Test results on synthetic walkaway VSP data and field data show that joint interferometric imaging is very effective.本文将相干成像用于WVSP数据的一次反射波和下行地表多次波的成像中,通过对叠加次数分布的分析,发现一次反射波相干成像的成像范围小但在井位置处的叠加次数高;下行地表多次波相干成像的成像范围大而在井位置处的叠加次数少。基于此,本文尝试利用一种WVSP的联合相干成像方法来解决这一问题。该方法利用WVSP的直达波与下行地表多次波和直达波与一次反射波来进行联合相干成像。这种联合相干成像方法在有效拓宽成像面积的同时增加了覆盖次数(特别是在井旁),使干涉记录中的虚假同相轴得到了有效地压制,提高了成像剖面的信噪比,使成像结果更加可靠。正演模拟得到的WVSP合成记录和野外实际采集到的WVSP数据处理结果均表明这种方法的有效性。

关 键 词：INTERFEROMETRY IMAGING multiple wave walkaway VSP 

分 类 号：P631.4[天文地球—地质矿产勘探]