Analysis on inversion accuracy of near-surface model inversed by first break traveltime tomography
LI Yu1, YANG De-yi2, DENG Hui3, YAN Rui1, CHEN Feng-ying1
1 State Key Laboratory of Coal Resources and Safe Mining,China University of Mining & Technology,Beijing,100083,China;
2 Mining Engineering College,Taiyuan University of Technology,Taiyuan,Shanxi,030024,China;
3 Institute of Resource Survey and Assessment,East China Mineral Exploration and Development Bureau,Nanjing,Jiangsu,210007,China
Abstract：In order to improve the inversion accuracy of near-surface model inversed by first break traveltime tomography,and then to enhance static corrections more effective,the paper discusses the impact of source depth and constraint velocity on the inversion accuracy.Based on typical synthetic near-surface model,we adopt analysis on the characteristic of ray paths from the source on the surface,the source below weathering and the source below sub-weathering.We discuss the impact of the minimum constraint velocity on the inversion of the weathering when source depth is below weathering.Furthermore,uphole time is involved to determine the minimum constraint velocity and a new method to determine the minimum constraint velocity,called auxiliary source,is also described.Finally the method is applied both to synthetic data and real seismic data and results show that the inversion accuracy is improved.
李宇, 杨德义, 邓辉, 严锐, 陈凤英. 初至旅行时层析反演近地表模型精度分析[J]. 石油地球物理勘探, 2011, 46(2): 221-225.
LI Yu, YANG De-yi, DENG Hui, YAN Rui, CHEN Feng-ying. Analysis on inversion accuracy of near-surface model inversed by first break traveltime tomography. OGP, 2011, 46(2): 221-225.
