一种τ-p域二维控制束成像方法  

A 2D control beam migration in the τ-p domain

作　　者：黄建平[1,2] 吴建文 杨继东 段新意 袁茂林 

机构地区：[1]中国石油大学(华东)地球科学与技术学院,山东青岛266580 [2]Earth Science of Rice University,Texas,USA 77005

出　　处：《石油地球物理勘探》2016年第2期342-349,208,共8页Oil Geophysical Prospecting

基　　金：国家自然科学基金项目(41104069,41274124);山东省自然科学基金项目(ZR2011DQ016);中央高校基本科研业务费专项基金项目(R1401005A)联合资助

摘　　要：实际地震数据中通常存在一定的背景噪声及人为施工噪声等干扰信号,根据有效信号和干扰信号在τ-p域的能量差异,在高斯束成像时采用阀值滤波的思想对干扰信号进行控制,并将滤波后的地震记录用于后续的扫描成像,发展了一种高斯控制束偏移方法。控制束偏移的本质为:1在τ-p域内根据实际地震资料的品质设定阈值,并对数据进行适当切除,以压制实际地震数据中的随机噪声干扰。2对处理后的地震记录进行加窗局部倾斜叠加。理论分析表明,由于在τ-p域中有效降低了远离中心射线的同相轴或非相干同相轴的振幅,提高了地震同相轴的横向连续性,从而大大降低了偏移噪声。Marmousi模型试算及实际资料成像处理结果表明,控制束偏移方法能够在一定程度上提高低信噪比数据的偏移效果,随着资料信噪比的提高,控制束偏移方法的改进效果减弱。Ambient noise and man-made noise are usually mixed in seismic shot gather.Based on energy difference between signal and noise in theτ-p domain,we propose a Gaussian control beam with a threshold filtering to eliminate noise during the Gaussian beam image process.The keys of the control beam method are as follows:A.A threshold is set based on the quality of the field data in theτ-pdomain,and ticks off noisy data to remove random noise from field data;B.Then a windowed local slant-stack is applied on the processed field data.Theoretical analysis shows the event continuity is improved and migration artifacts are significantly suppressed because energy of events far away from the central ray path is decreased in theτ-pdomain.Tests on Marmousi model and field data suggest that the proposed control beam migration can increase the migration quality for low signal to noise ratio(SNR)data.

关 键 词：高斯束偏移 阀值滤波 加窗局部倾斜叠加 Τ-P域 控制束偏移 

分 类 号：P631.443[天文地球—地质矿产勘探]