不同时频变换谱比法品质因子Q估算效果对比分析

Comparative analysis of quality factor Q estimated by spectral ratio method based on different time frequency transform

基于时频分析技术的谱比法品质因子Q估算已成为地震资料Q估算最常用、最有效的方法之一.针对目前常用的短时傅里叶变换(STFT)、小波变换(WT)和S变换(ST)三种时频分析方法,基于三层水平层状介质模型的衰减地震响应,对比分析了三种时频变换谱比法品质因子Q估算应用效果.结果表明,基于S变换的谱比法Q估算精度最高.进一步针对不同厚度气层楔状模型衰减地震响应,采用基于S变换的谱比法探讨了获得理想Q估算值的最小含气储层厚度应不小于地震子波的主波长.

The spectral ratio method based on time frequency analysis technique has become one of the most commonly used and effective methods for seismic data Q estimation. According to three commonly used time-frequency analysis methods,which are Short Time Fourier Transform（ STFT）,Wavelet Transform（ WT） and S Transform（ ST）,it is analyzed that the application effect of three time frequency transform used in spectral ratio method quality factor Q estimation based on the attenuation seismic response of three layered medium model. Results shows that the spectral ratio method based on S transform can get the highest accuracy of Q estimation.Meantime,the minimum gas reservoir thickness to get ideal Q estimation value,which should not be less than the main wavelength of the seismic wavelet, is analyzed for the attenuation seismic response of different thickness gas layer wedge model by the spectrum ratio method based on S transform.