基于短算子设计的黏性介质叠前时间偏移  

Prestack time migration in anelastic media based on designing for short operator

作　　者：李雪英[1] 吕喜滨[1] 张剑锋[2] 

机构地区：[1]东北石油大学地球科学学院,大庆163318 [2]中国科学院地质与地球物理研究所,北京100029

出　　处：《地球物理学报》2011年第1期193-199,共7页Chinese Journal of Geophysics

基　　金：国家自然科学基金重点项目(40930422);国家油气重大专项(2008ZX05023-005-010)联合资助

摘　　要：为了提高频域黏性介质叠前时间偏移的计算效率,本文采用加权最小平方方法设计高精度的、最优时域褶积短算子,发展了一套表驱动的时域黏性介质叠前时间偏移方法.该方法将大量的逐频率补偿运算转化为少量的时域褶积运算,并将走时、振幅表和补偿褶积短算子系数表的计算过程与补偿成像过程相剥离,提高了时域算法的计算效率;通过控制最大的补偿因子,保证了黏性吸收补偿的稳定性.二维黏性介质理论模型处理结果表明:加权最小平方方法设计的短算子具有很高精度,时域算法与频域算法的补偿成像效果基本相同,但计算量却与常规叠前时间偏移相接近.In order to raise the computational efficiency of frequency domain prestack time migration in anelastic media, the high-accuracy optimum short convolution operators in time domain are designed by weighted least squares method. Therefore a table-driven time domain prestack time migration scheme in anelastic media is presented. This scheme can transform large amount of multiplication operation frequency by frequency into less convolution operation in time domain and split calculation of travel time, amplitude and short convolution operator from the inverse Q compensation migration, which greatly improved the computational efficiency of time-domain pre-stack time migration in anelastic media. A stabilization controlling strategy is proposed to ensure the stability of arithmetic in compensation for absorption and dispersion. Numerical examples indicate that the short convolution operator has very high accuracy designed by weighted least squares method. The algorithm in time domain can achieve the same compensation result as in frequency domain while its computational cost is close to the conventional prestack time migration.

关 键 词：黏性介质 叠前时间偏移 褶积短算子 加权最小平方方法 表驱动 

分 类 号：P631[天文地球—地质矿产勘探]