Seismic physical modeling and quality factor

摘要

Accurate Q parameter is hard to be obtained,but there is great difference between Q measurements from different measurement methods in seismic physical modelling.The influence factors,stability and accuracy of different methods are analyzed through standard sample experiment and the seismic physical modelling.Based on this,we proposed an improved method for improving accuracy of pulse transmission method,in which the samples with similar acoustic properties to the test sample are selected as the reference samples.We assess the stability and accuracy of the pulse transmission,pulse transmission insertion,and reflection wave methods for obtaining the quality factor Q using standard and reference samples and seismic physical modeling.The results suggest that the Q-values obtained by the pulse transmission method are strongly affected by diffraction and the error is 50％ or greater,whereas the relative error of the improved pulse transmission method is about 10％.By using a theoretical diffraction correction method and the improved measurement method,the differences among the Q-measuring methods can be limited to within 10％.