Estimation Of Q Values Based On Redatuming Operator In Prestack Seismic Data

The propagation of seismic waves in viscoelastic media is affected by the absorption attenuation effect,which is manifested by energy attenuation and velocity dispersion,which reduces the resolution of seismic data.Q-value extraction and inverse Q filtering techniques are important processes in the high-resolution processing of seismic data and are the main processing methods to eliminate the viscoelastic effects of the formation.The peak frequency algorithm(PFS)is a common method used in the Q value estimation of prestack CMP seismic data.It calculates the formation quality factor Q value by calculating the peak frequency of the seismic signal as a function of travel time.This method is simple and practical,but there is a problem of peak frequency and extraction accuracy during travel between formations.For the peak frequency of the peak frequency algorithm(PFS),this paper starts from the perspective of time-frequency analysis,combined with the time-frequency analysis method,extracts the accuracy of the formation quality factor of the peak frequency calculation by comparing different time-frequency analysis methods,and finds the appropriate time.Frequency analysis method;for the traveling time problem between layers,this paper combines the peak frequency algorithm with the wave field continuation operator,and derives the peak frequency algorithm(RPFS)based on the wave field continuation operator to extend the deep stratum upwards.When calculating the travel of seismic waves between the strata,the larger inter-layer travel time error in the peak frequency algorithm is corrected.After the iterative solution,the quality factor Q of the stratum can be calculated layer by layer.Based on the theoretical derivation,this paper analyzes the model data and actual data.The experimental results show that the generalized S transform can extract the peak frequency of the seismic signal more accurately,and the calculated quality factor has smaller error and better noise immunity.The peak frequency algorithm based on the wave field continuation operator(RPFS)The calculated error of the formation quality factor is much smaller than the peak frequency algorithm(PFS)in calculating the quality factor Q,and the RPFS algorithm has good stability and noise immunity.