Research On Optimization Of Different Q Value Estimation Methods Based On Prestack Seismic Data

Due to the viscosity of the stratum,attenuation will occur when the seismic wave propagates though it.The quality factor Q is an important parameter to quantitatively describe the inherent attenuation of the stratum.The method of estimating the Q value has always been a major research hotspot in seismic processing.Based on the traditional methods,this paper summarizes and proposes three innovative methods,namely the prestack centroid frequency method(QVOC),the Q value analysis method based on the amplitude attenuation,and a novel Q estimation method based on the method of logarithmic spectral area difference of high and low frequency(LSAD?LH).The applicability and advantages of the above methods are introduced from three aspects:theoretical derivation,simulation data application and field data application.This paper focuses on the LSAD?LH method.We define the difference between the low-frequency attenuation and the high-frequency attenuation as the attenuation parameter.Then we use simulated data to study the influence of noise sensitivity,frequency bandwidth selection in the low frequency part,initial frequency selection in the high frequency part,ray theory and reference wavelet on the method,and finally use the actual field data to prove that the LSAD?LH method can estimate the Q value stably and effectively.Since the general Q value estimation method assumes a constant Q model,the frequency-dependent Q only stays in the process of actual seismic data calculation and laboratory rock sample testing,and there are few reports on the seismic physical model.Up to now,the attenuation mechanism of the laboratory seismic physical model and the best estimation method for laboratory attenuation are not clear.In this paper,the two-parameter regression method is introduced into the attenuation measurement of the seismic physical model.By comparing the compensation results of the frequency-dependent Q and the frequency-independent Q,the frequency dependence of the attenuation measurement of the seismic physical model in the laboratory is proved,which provides a theoretical reference for subsequent research.