Research On Q Estimation And Inverse Q Filtering Methods

Generally,conventional seismic exploration adopts the elastic model to describe actual media.However,the wave behavior in real earth media is closer to viscoelastic.Viscoelasticity causes energy dissipation,amplitude attenuation and frequency reduction of seismic wave.Quality factor is the key parameter to characterize the absorption of propagation media.In seismic exploration,Q value can be used to analyze formation attenuation,provide information about energy compensation,and support for lithology as well as fluid bearing situation identification.Based on Q information for seismic data,this paper mainly studies Q estimation methods and energy compensation methodsIn Q estimation section,we introduce spectral ratio method and frequency shift method for VSP(Vertical Seismic Profiling)data.Peak frequency inversion method can be applied in CMP(Common Middle Point)gather data.In some zone of sharp lateral variation,the estimated Q value based on VSP data can only depict attenuation of near well area.This limitation affects the accuracy of amplitude compensation and phase correction.In order to accurately describe formation Q variation,we propose Q modeling method which integrates surface seismic velocity and Q value from VSP data.In inverse Q filtering section,we compare the compensation results of stabilized inverse Q method with Gabor deconvolution method.Considering time-frequency domain SNR(signal-to-noise ratio),the inverse Q method,which can improve the resolution of seismic data without reducing its SNR,is suitable for low SNR data.The application results of synthetic and real data elucidate the effectiveness of this method.