Inverse Gaussian beam stacking method for imaging both primary reflections and free-surface multiples in 2D VSP. (29th July 2020)

• Record Type: Journal Article
• Authors: Yang, Feilong; Huang, Dezhi; Yang, Jidong; Yu, Dai; Luo, Hao; Zhao, Chi; Zhao, Chong
• Is Part Of: Journal of geophysics and engineering. Volume 17:Number 5(2020)
• Page Start: 852
• Page End: 860
• Publication Date: 2020-07-29
• Subjects: vertical seismic profiling -- inverse Gaussian beam stacking -- imaging -- primary reflections -- free-surface multiples; Geophysics -- Periodicals; Prospecting -- Geophysical methods -- Periodicals; Engineering -- Periodicals; 622.1505
• DOI: 10.1093/jge/gxaa034
• Languages: English
• ISSNs: 1742-2132

Abstract

Abstract: In vertical seismic profiling (VSP) exploration, it is difficult to produce an accurate image for large-offset reflections only using reflection waves and the image resolution is low in traditional VSP-CDP stacking as is the number of folds of reflection points. To mitigate these problems, we present an inverse Gaussian beam stacking method for imaging both primary reflections and free-surface multiples. We first compute the stacking weighted functions at each trace location by Gaussian beam forward modeling, and then apply an inverse projection for VSP data to produce common shot gathers (CRP). Since inverse Gaussian beam stacking maps the common-shot data along finite-frequency wave-paths instead of single rays as the traditional ray-based stacking method does, it enlarges the reflection-point coverage, increases stacking fold and reduces the requirement for large bin sizes. We incorporate free-surface multiples into the proposed inverse Gaussian beam stacking, which enables us to expand the horizontal imaging aperture and mitigate the low-fold problem of primary reflections in the shallow large-offset regions for VSP surveys. Numerical examples for synthetic and field data demonstrate the feasibility and adaptability of the proposed inverse Gaussian beam stacking method for VSP data.