Converted-Wave Static Correction Method for Thick Weathering Area
详细信息
- 责任者：Li Yanpeng (School of Ocean and Earth Science ; Tongji University ; Shanghai 200092 ; China) ; Ma Zaitian
- 刊名：Chinese Journal of Geophysics
- 出版年：2012
- 卷期：55(2)
- 关键词：转换波 ; converted waves
- 页码：p.614-621
- 图表：9 illus., 21 refs.
- 分类号：1600
- issnNo：ISSN0001-5733
- isbnNo：CN11-2074/P
摘要
In P-SV seismic data processing,there are some aspects different from conventional P-P seismic data processing,such as S-wave static correction,CCP binning,P-SV velocity analysis and migration.Among them,the most difficult procedure is S-wave static correction.Unlike P-wave velocity,the S-wave velocity is almost unaffected by the water table and generally very low.Hence,the P-wave and S-wave static solutions are largely different from each other,sometimes S-wave statics are near ten times of P-wave′s.So the approximation of the S-wave statics by simply scaling the known P-wave statics will lead to large errors and a good image can not be obtained.It has been proven that the time difference of first break between X and Z component in same receiver represents the travel time difference of P-and S-wave in weathering layer and it can be utilized to calculate S-wave statics.This paper presents an accurate statics expression with respect to the time difference of first break and some velocity ratio parameter of near surface.Combined with residual statics estimated from common receiver stack section,an integrated converted-wave static correction method has been presented.The method was applied to 2D-3C and 3D-3C data processing of Shulige gas field.The results show a good image which indicates that this method is effective for P-SV data processing.This method is especially suitable for statics estimation of thick weathering area where other methods are disabled.Long period S-wave statics are considered simultaneously.