利用广义S变换进行等效Q值扫描分析

Scanning analysis of effective Q using generalized S transform

本文首次给出了一种利用扫描分析技术与广义S变换时频分析工具相结合求取介质品质因子(Q值)的方法,与传统的Q值估计方法不同,该方法用一系列等效Q值对叠前衰减数据进行粘性补偿偏移,将偏移后的共反射点道集叠加,利用广义S变换求取补偿后叠加道的时频谱和傅立叶峰值频率,以浅层强反射界面子波时频谱为参考,它他深度处地层子波的时频谱特征与之进行比较,当谱宽和峰值频率达到一致作为正确Q值选定标准,确立了宏观介质的等效Q值分析新方法.

A new method of determining effective Q is presented for the first time which is combined with the generalized S transform and scanning analysis technique. It differs substantially from traditional Q estimation methods in that prestack time migration is adopted to compensating for seismic data, which has been attenuated as a result of intrinsic absorption, by using a series of effective Q factors. Common reflection point gathers are stacked in order to form the stacked profile. A stacked trace chosen from the stacked profile is analyzed by using generalize S transform to gain the time-frequency spectrum and peak frequency of Fourier spectrum. A shallow strong reflection can be selected as a reference time-frequency spectrum. This reference spectrum is compared with the target reflection at different depths. A standard is established for choosing accurately effective Q when the spectrum width and peak frequency of Fourier spectrum are consistent with reference spectrum. As a result, a new technique for analyzing effective Q of macro media is established.