Research On Attenuation Compensation Method Based On Time-Frequency Analysis

Seismic waves will be affected by the absorption effect of the stratum,which will be causing seismic wave energy attenuation and phase distortion and seriously reduce the resolution of seismic data in the process of underground propagation.With the increasing difficulty of exploration,the attenuation effect of seismic waves must be eliminated.The study of attenuation compensation is of great significance to the inversion of the properties of underground media,the prediction of reservoirs and the improvement of the accuracy of seismic imaging.Because seismic data are non-stationary signals,we consider implementing attenuation compensation in the time-frequency domain in order to better describe the time-variability of attenuation compensation operators.Geophysicists have achieved attenuation compensation based on Gabor transform and wavelet transform,respectively.However,the accuracy between different time-frequency domain compensations is not analyzed.Based on this,this paper studies the attenuation compensation method based on time-frequency analysis.In this paper,the commonly used time-frequency analysis methods are introduced in detail(Gabor transform,wavelet transform,and generalized S transform)and performed time-frequency analysis on synthetic seismic signals.Among them,the time window of the generalized S transform is flexible,and the time-frequency focus is better,which can be better used for seismic data processing.we implement the attenuation compensation based on Gabor transform and continuous wavelet transform,and popularize the attenuation compensation based on generalized S-transform.Aiming at the problem of noise amplification in the compensation process,a variable stability factor process is introduced in the compensation process.Compared with the constant stability factor method,this method can avoid the amplification of noise energy in seismic data and effectively improve the signal-to-noise ratio of the seismic data.We analyses the accuracy of three kinds of time-frequency domain compensation through numerical simulation.It can be concluded from the error analysis that the compensation based on GST has higher accuracy than the Gabor transform and CWT.The compensation results of field seismic data show the effectiveness of the method,and verify that the method can improve the accuracy of the real seismic data compensation processing.