An Improved Method to Estimate Q based on the Logarithmic Spectrum of Moving Peak Points
Y. Liu, Z. Li, G. Yang, W. Cao and Q. Liu
Event name: 80th EAGE Conference and Exhibition 2018
Session: Poster: Seismic Attenuation A
Publication date: 11 June 2018
Info: Extended abstract, PDF ( 1.54Mb )
Price: € 20
Quality factor (Q) is an important parameter to measure the attenuation of seismic waves. Many methods of estimating Q are based on the individual wavelet. However, the individual wavelet could not be extracted precisely form reflection seismic data. In this paper, the feasibility of estimating Q from seismic data was proved theoretically in this paper. The core part of the method is selecting the peak frequency points to fit their logarithmic spectrum and time-frequency product. First, to get the peak frequency points at different time, the generalized S transform (GST) is applied to produce the 2D high precision time-frequency spectrum. According to the seismic wave attenuation mechanism, the logarithmic spectrum is linear-attenuated with the product of frequency and time. So the second step of the method is transforming the 2D spectrum into 1D by the way of variable substitution. Different from other people, we just selected the peak frequency points to participate the fitting process, which can reduce the impact of the interference on the spectrum. Third, the last-squares fitting is conducted to get the optimized slope. Both the model and real data indicates that our method is an effective and reliable method to estimate the Q value.