摘要
本文讨论地震勘探数据的叠前速度反演方法及其在海洋地震勘探数据上的反演试验.反演主要的计算步骤是:1.采用Fourier-Hankel变换把球面波分解为平面谐波;2.用平面谐波的延拓方程将上行波与下行波同时向下延拓,并计算每一层底部的反射系数和下一层的波阻抗;3.用最小二乘法从波阻抗中确定该层的声波速度.重复第2步与第3步,直到某一预定深度时结束.通过反演试验,对地震振幅比例的改变,子波变形,以及第1层速度和密度的误差对反演方法的稳定性及其精度的影响进行了分析.还通过实际海洋地震勘探数据的反演试验,对这一方法在地震勘探中的应用前景作了论述.
This paper deals with the method of prestack velocity inversion of seismic data and results of inversion on the marine data. The geophysical model for the inversion is 1(1-D acoustic layered medium) +2(2-D seismic data--CDP data set) +3(3-D spherical wavefield--point source). The computation steps are: 1. plane wave decomposition using Fourier-Hankel transform; 2. extrapolate the upcoming and down-going wavefield simultaneously, to obtaine the reflection coefficient and impedance at the bottom of each layer; 3. determine the velocity of each layer by the least-square technique until a required depth has been reached. Inversion experments on the synthetic data used for analyzing the effect of scaling, wavelet distortion, initial velocity and density on the accuracy and stability of the method has been studied. Inversion experments on marine seismic CDP data set shown that the inversion velocity profile can be used for geological interpretation.
出处
《地球物理学报》
SCIE
EI
CAS
CSCD
北大核心
1993年第3期388-395,共8页
Chinese Journal of Geophysics
关键词
地震波
速度
叠前反演
延拓方程
Seismic velocity, Prestack inversion, Downward continuation equation.
