摘要
黏弹性叠前时间偏移通过在偏移过程中补偿地球介质的吸收衰减,恢复被衰减的高频成分,进而获得较常规叠前时间偏移更高分辨率的偏移成像结果.相比于常规叠前时间偏移,该方法实现环节包含的频率域积分产生的巨大计算量,需要基于GPU加速实现才能满足工业应用对其计算效率的需求.本文针对黏弹性叠前时间偏移算法实现的这一特点,提出了修正其走时计算方法精度和应用分时段的频率域成像策略,在进一步提升计算效率的同时,改进了该方法对陡倾角构造和断层的成像效果.我们将改进的黏弹性叠前时间偏移方法应用于三维陆上地震资料,与现行的商业偏移软件对比表明,该方法不仅获得了更高分辨率的成像结果,也实现了对断层和陡倾角构造的清晰成像,而新方法的计算耗时也较改进前减少了三分之一以上.
De-absorption pre-stack time migration （PSTM） can compensate absorption and dispersion via an actual wave propagation path using effective Q parameters. Compared with conventional pre-stack time migration, it has higher resolution image. In this paper, we modified the conventional travel time method to a high order one by introducing two non-dimensional parameters. These parameters are obtained by optimizing the travel time equation and the travel time calculated using the Snell＇s law. To improve the robustness of imaging steep-dip structure and faults, we present a new travel time calculation method useful for graphic process unit （GPU） and a seismic trace split method. Applying the method to the real 3D land seismic data produces significant improvements in resolution especially in steep-dip structure and faults. At the same time, the improved method can reduce the calculation time by more than one third.
出处
《地球物理学报》
SCIE
EI
CAS
CSCD
北大核心
2018年第2期707-715,共9页
Chinese Journal of Geophysics
基金
国家自然科学基金重点项目(41330316)和国家科技重大专项(2017ZX05008-007)资助.
关键词
黏弹性
叠前时间偏移
陡倾角
走时
计算效率
Viscoelastic media
Pre-stack time migration
Steep dip structure
Travel time
GPU speed up
