Research and Modification of VSP Attenuation Characteristics Based on Ganley’s Forward Theory

详细信息   

• 责任者：Wu Yinting (Institute of Geology and Geophysics ; China Academy of Sciences ; Beijing 100029 ; China) ; Zhu Guangming
• 刊名：Chinese Journal of Geophysics
• 出版年：2011
• 卷期：54(9)
• 关键词：垂直地震剖面 ; vertical seismic profiles ; 衰减 ; attenuation ; 正演问题 ; forward problem
• 页码：p.2368-2374
• 图表：illus., 1 table, 20 refs.
• 分类号：1600
• issnNo：ISSN0001-5733
• isbnNo：CN11-2074/P

摘要

VSP data can provide abundant information of seismic wave attenuation characteristics. This paper carries out forward calculations of zero-offset VSP synthetic record with attenuation. Considering reflection and refraction, the synthetic seismograms of layered attenuation models are generated based on Ganleyrs theory, which is fit for normal incident. Compared with the records without attenuation, the decrease of energy and frequency display the unelastic characteristics. We calculated the down-going and up-going wavefield with source location on the surface and underground. Unfortunately, the forward results showed that the arrival time shifted up in the down-going wavefield when the source was underground, which indicates problems in the original formula. We modify the transmission matrix and gain a corrected record, which corresponds with regular pattern.