The conventional method for calculating the quality factor Q by using the first arrival wave greatly depends on the quality of the first arrival wave and can not be time-varying, so satisfactory compensation results can not be obtained. In this paper, a method of near surface Q calculation and quantitative compensation based on reflection wave is proposed. Firstly, the reflection wave in the specified time window is used to calculate the centroid frequency of source and receiver points. Next, after offset correction, combined with the surface travel time, the frequency shift method is used to establish the near-surface Q model. And then, the stable Q compensation algorithm with gain control is used to realize the time-varying and space varying Q compensation of source and receiver points. An application example of lithological exploration in Qaidam Basin in western China shows that the Q model obtained by this method is more reasonable. On the basis of maintaining low-frequency signals, the effective frequency band of seismic data is widened, and the resolution is significantly improved without reducing signal-to-noise ratio. At the same time, the problem of inconsistencies in amplitude and phase of multi-survey joint data is solved, which provides high-fidelity basic data for lithological exploration.
Presentation Date: Monday, October 12, 2020
Session Start Time: 1:50 PM
Presentation Time: 2:40 PM
Location: Poster Station 5
Presentation Type: Poster
