Estimation of Relative Absorption Coefficient Using Pre-Stack Seismic Data
详细信息
- 责任者：He Binghong (School of Geosciences ; China University of Petroleum ; Qingdao 266555 ; China) ; Wu Guochen11.
- 刊名：Oil Geophysical Prospecting
- 出版年：2012
- 卷期：47(4)
- 关键词：地震勘探 ; seismic exploration ; 正演模拟 ; forward modelling
- 页码：p.610-618, 681
- 图表：4 illus., 1 table, 11 refs.
- 分类号：1600
- issnNo：ISSN1000-7210
- isbnNo：CN13-1095/TE
摘要
Based on seismic forward-modeling of attenuation medium,we estimate the relative absorption coefficient,one of the absorption parameters,by S transform,according to the relationship between the amplitude in the frequencies which is symmetric about the peak frequency.In the light of the relationship between the absorption coefficient and quality factor Q,we derive what the relative absorption coefficient have to do with offset.And then,a more reliable relative absorption coefficient is calculated,which is independent of offset through multi-channel fitting method.Finally,a model is established to estimate the relative absorption coefficient from the synthesis CMP gathers in attenuation medium based on non-zero offset one-way wave equation.We also apply this method to pre-stack seismic data in angle domain.Relative absorption coefficient is estimated from near,middle and far angle gathers and fitted.In this way,the high relative absorption coefficient indicating cap rock and reservoir filled with water on post-stack seismic data are eliminated on pre-stack seismic data.Compared with that coming from single angle seismic data,relative absorption coefficient obtained from pre-stack seismic data in angle domain can suppress the illusive high relative absorption coefficient caused by strong reflection of cap rock.As a result,more reliable oil and gas indication,and a more accurate reservoir prediction are achieved.Both synthesis data and real data examples show the effectiveness of the method.