Causes and Solutions of A Low Signal-To-Noise Ratio of Seismic Data in Complex Areas, Part Ⅱ: Basic Property and Shape Features of Surface Scattered Waves

详细信息   

• 责任者：Wu Xiguang (Geophysical Exploration Company of Chuanqing Drilling Engineering Co. ; Ltd. ; CNPC ; Chengdu 610213 ; China) ; Li Zhirong
• 刊名：Natural Gas Industry
• 出版年：2012
• 卷期：32(2)
• 关键词：地震勘探 ; seismic exploration ; 信噪比 ; signal-to-noise ratio
• 页码：p.38-42
• 图表：illus., 4 refs.
• 分类号：1600
• issnNo：ISSN1000-0976
• isbnNo：CN51-1179/TE

摘要

 This paper aims to further understand the nature of scattered waves and provide basic data for the development of scattered wave suppression techniques.Therefore,from simple to complex and from specific to general,we studied the basic properties and shapes of scattered waves,beginning with the simple and visualized seismic records of both scattering sources and corresponding scattered waves.In 3-D space,a single scattered wave is in linear or near linear shapes and can be classified into forward scattered wave,reverse scattered wave,and bidirectional scattered wave when the scattering source is located on or close to seismic lines.In contrast,scattered waves show hyperbolic curve shape when the scattering source is far away from the seismic lines.The crest of a scattered wave is located at the subpoint of the scattering source on seismic lines.The trend lines on both sides are parallel or sub-parallel to surface waves.Scattered waves mainly occur in the triangle area between surface waves,their frequencies are in the range from several to 30 Hz or so,and their velocities are similar to those of surface waves.The complex interference setting of real seismic records is resulted from the superimposition of numerous single scattered waves.Scattered wave interference is the basic cause of a low signal-to-noise ratio in complex areas.These understandings can contribute to the suppression of scattered waves.