预条件最小二乘逆时偏移方法  

Preconditioned least-squares reverse time migration

作　　者：李闯 黄建平[1,3] 李振春 王蓉蓉[2] 李庆洋[1] 

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]中国石油大学(华东)信息与控制工程学院,山东青岛266580 [3]Earth Science Department of Rice University, Houston, 77005, USA

出　　处：《石油地球物理勘探》2016年第3期513-520,416,共8页Oil Geophysical Prospecting

基　　金：国家“973”课题(2014CB239006,2011CB202402);国家自然科学基金(41104069,41274124);中国石化地球物理重点实验室开放基金(33550006-15-FW2099-0033);中央高校基本科研业务费专项资金(16CX06046A)联合资助

摘　　要：针对最小二乘逆时偏移方法收敛速度较慢,并且对深部及盐下构造照明补偿不足的问题,结合Hessian算子的近似及一种快速高通滤波方法对梯度进行预处理,发展了一种预条件最小二乘逆时偏移算法。在实现算法的基础上对SEG/EAGE二维盐丘模型进行了成像测试。计算结果表明:预条件最小二乘逆时偏移方法能够加快收敛速度,提高深部及盐下构造成像的分辨率和保幅性,对不规则的地震数据,该方法具有更好的适应性。Conventional least-squares reverse time migration(LSRTM)has some defects such as slow convergence and insufficient compensation to unbalanced illumination in deep and subsalt structures.To solve these problems we present in this paper an idea of a preconditioned least-squares reverse time migration,in which an approximate Hessian matrix and a fast high-pass filter are applied to the gradient as the preconditioning.Numerical tests on2DEAGE/SEG salt model show that the proposed migration can accelerate the convergence,improve the resolution and amplitude preservation of deep and subsalt structure images,and reduce sensitivity to irregular shot data compared with conventional least-squares reverse time migration.

关 键 词：最小二乘偏移 预条件算子 HESSIAN矩阵 计算效率 保幅偏移 

分 类 号：P631[天文地球—地质矿产勘探]