Seismic Thin Interbeds Analysis Based on High-Order Synchrosqueezing Transform

Thin interbeds, which are made of several thin layers, are critical geological structures in seismic exploration. Due to the limited seismic resolution, thin interbeds cannot be easily analyzed with the standard time analysis or frequency analysis from a seismic dataset. Time-frequency (TF) analysis is a powerful technique for analyzing a nonstationary signal in the time and frequency domains simultaneously. Although it is tough to use the TF tool to estimate the thin layer’s thickness, TF analysis still has much potential for analyzing seismic thin interbeds from seismic data. The high-order synchrosqueezing transform (SST) has a significantly higher TF resolution than the linear TF transform and some commonly used SSTs. In this study, we propose to utilize the high-order SST to extract the TF features of thin interbeds’ seismic response. The TF analysis on the seismic response of cyclic thin interbeds shows that the thickness variation in thin interbeds causes a clear increasing (or decreasing) frequency curve in the TF plane. A seismic data example based on the Marmousi2 model demonstrates the proposed method can reflect the thickness variation with the depth. One real seismic data example has shown that the high-order SST can specifically extract the frequency component and be used to characterize the thickness variation, which is verified by two well’s velocity logs.