非分裂完全匹配层边界存储时间域全波形反演  

Time-domain full waveform inversion with CFS-NPML boundary storage

作　　者：成景旺[1] 毛宁波[1] 吕晓春[2] 常锁亮[3] 严皓 仲华 

机构地区：[1]油气资源与勘探技术教育部重点实验室(长江大学),湖北武汉430100 [2]华北水利水电大学资源与环境学院,河南郑州450011 [3]太原理工大学矿业工程学院,山西太原030024 [4]中海石油(中国)天津分公司,天津300452

出　　处：《石油地球物理勘探》2018年第4期754-764,共11页Oil Geophysical Prospecting

基　　金：国家自然科学基金项目(41504102);湖北省"地球内部多尺度成像"重点实验室开放基金项目(SMLL-2015-08);长江大学长江青年基金项目(2015cqn32)联合资助

摘　　要：正演波场的储存或重建是制约时间域全波形反演的关键问题,以计算代替存储的常规分裂完全匹配层(PML)边界存储策略可有效减少存储量。但常规分裂PML边界条件所需变量个数多、计算存储量大以及编程复杂。为此,采用非分裂复频移完全匹配层(CFS-NPML)有效边界存储策略重建正演波场实现时间域全波形反演。研究表明:CFS-NPML所需变量个数少,在边界吸收层网格点较少时吸收效果优于常规PML边界条件,波场重建过程中所需存储量少于常规PML边界条件。数值试验表明,该存储策略得到的重建波场与正向传播波场几乎无差别,其全波形反演结果与常规保存波场反演法一致;正演过程中引入并行计算技术未显著增加波场重建导致的额外正演时间。The forward-modeling wavefield storage or reconstruction is a key question in the time-domain full waveform inversion.The strategy of storage replaced by computation based on conventional splitting perfect matched layer(SPML)boundary conditions can effectively reduce the amount of storage.However,conventional SPML boundary conditions require a large number of variables,a large amount of memory,and complex programming.In this paper,an effective boundary storage strategy based on the complex frequency shifted non-splitting perfect matched layer(CFS-NPML)is proposed to reconstruct the forward-modeling wavefield to realize the time-domain full waveform inversion.According to our study,fewer variables in CFS-NPML are needed;the absorption effect is better than conventional SPML boundary conditions when grid points of the boundary absorption layer are less.So less storage capacity is needed than that of conventional SPML boundary conditions in the wavefield reconstruction process.Numerical experiments show that there is almost no difference between the forward-modeling wavefield and the reconstructed wavefield obtained with this storage strategy.The velocity obtained by the full waveform inversion with this storage strategy is consistent with that obtained by the conventional storage wavefield inversion.The wavefield reconstruction does not significantly increase the computer time consuming thanks to parallel computation introduction.

关 键 词：非分裂完全匹配层 边界存储 时间域 全波形反演 

分 类 号：P631[天文地球—地质矿产勘探]