零偏移距VSP直达子波振幅衰减值的提取及应用

EXTRACTION AND APPLICATION OF DIRECT WAVELET AMPLITUDE IN ZERO-OFFSET VSP

煤炭工业部地球物理勘探公司

用零偏移距VSP不同深度点上观测的直达子波振幅,可直接提取有限测试距离上的振幅衰减值,进而求得不同频率时介质的吸收系数、品质因数、波阻抗参数及介质吸收系数与频率的关系本文根据模型地震试验,提供了VSP直达子波振幅衰减值的提取方法,并从数值上给出了各种参数的实验结果。定量研究这些参数有助于揭示介质的力学性质及空间分布。

By dint of the direct wavelet amplitudes recorded in different depths in zero-offset VSP, the values of attenuation of amplitude within limited test range could be directly extracted and the absorption coefficients, the quality factors and the impedance parameters for different frequencies as well as the relationship between the absorption coefficient and the frequency could thus be obtained.Based on the seismic model experiments. the technique for extracting the attenuation values of the direct wavelet amplitudes from VSP data was given and the values of the parameters obtained from experiments were also presented. The study of these parameters will be of some help in revealing tge mechanical character of the medium and its spatial distribution.