摘要
逆时偏移是针对复杂构造的主流叠前深度偏移成像技术,常规逆时偏移技术大多采用高阶有限差分和成像后滤波算法。由于实际偏移的计算网格较大造成空间频散现象和成像后的去低频噪声滤波会损害有效低频信息,因此成像频宽受到一定影响。为此,提出基于GPU的傅里叶有限差分逆时偏移方法。即采用傅里叶有限差分算法进行波场传播计算,波场外推中直接在时间—波数域做显式波场分解和互相关成像;同时采用基于GPU的算法,显著提高了傅里叶有限差分逆时偏移的计算速度。实际资料应用结果表明,该技术能实现对高、低频有效信息的充分保护和利用,从而提高了地震成像分辨率。
Reverse time migration(RTM)is a pre-stack depth migration technique commonly used for imaging complex structures.In conventional RTM,high-order finite difference and post-imaging filtering algorithms are usually used,but spatial dispersion will be caused by large computing girds and effective low-frequency information will be lost when using post-imaging filtering to remove lowfrequency noises.A GPU-based Fourier finitedifference RTM method is developed.It uses the Fourier finite-difference algorithm to calculate wavefield propagation,and explicit wavefield decomposition and cross-correlation imaging are directly performed in time-wavenumber domain during wavefield extrapolation.In addition,the GPUbased algorithm can significantly improve the calculation speed of Fourier finite difference RTM.The application in field data shows that the method can protect and utilize the high and low frequency information effectively,so the imaging resolution can be improved apparently.
作者
段心标
DUAN Xinbiao(Wave Phenomena and Intelligent Inversion ImagingGroup(WPI),Tongji University,Shanghai 200092,China;Sinopec Geophysical Research Institute,Nanjing,Jiangsu 211103,China)
出处
《石油地球物理勘探》
EI
CSCD
北大核心
2020年第5期1039-1046,933,共9页
Oil Geophysical Prospecting
基金
国家重点研发计划项目“深层含盐层系复杂波场高精度地震成像”(2017YFC0602804-02)
国家科技重大专项“缝洞储集体高精度地震成像技术研究”(2016ZX05014-001-002)联合资助
关键词
逆时偏移
傅里叶有限差分
解析波场分解
成像频带
reverse time migration(RTM)
Fourier finite-difference
analytical wavefield decomposition
imaging bandwidth
作者简介
段心标,副研究员,在读博士,1982年生,2005年获中国石油大学(华东)勘查技术与工程专业学士学位,2008年获中国科学院地质与地球物理所固体地球物理学硕士学位,现就职于中国石化石油物探技术研究院,主要从事地震偏移成像技术研发及推广应用。Email:duanxb.swty@sinopec.com
