海底多分量数据的弹性参数多尺度反演

Multiscale inversion of elastic parameters with multi-component seismic data under seabed

1. 中国地质大学,湖北武汉430074;2. 西安工程学院,陕西西安710054

1. Dept. of Geophysics, China University of Geosciences, Wuhan 430074,China;2. Applied Geophysical Research Institute, Xi'an Engineering College, Xi'an 710054, China

海底多波多分量地震资料,能够提供含气高压地层的地质信息,提高AVO反演岩性参数的可靠性。应用计算反射系数的Zoeppritz方程,实施海底多波多分量数据的弹性参数的多尺度AVO反演。考虑的弹性参数是介质两侧速度及密度比,在时空域内建立多波AVO联合反演的目标函数;应用小波多尺度分析,对目标函数进行多尺度分解,并通过奇异值分解 (SVD)实现每一尺度内极值点的弹性参数求解;采用剥层法逐层多尺度反演多个地层弹性参数。

Multi-wave multi-component seismic data under seabed can reveal the geological information of high-pressure gas-bearing beds and improve the reliability of AVO inversion for elastic parameters. We adopt Zoeppritz equation to carry out multiscale AVO inversion of elastic parameters on multi-wave seismic data under seabed. The inverted elastic parameters are ratios of velocities and densities at the two sides of an interface and a joint inversion objective function is built in time domain. The objective function is decomposed by multiscale analysis and the elastic parameters in each scale are resolved by using SVD. Tests with synthetic and real data show that the method is fast and robust.