Multi-scale frequency and absorption attributes of seismic signals

摘要

Seismic absorption is sensitive to gas saturation, and this can lead to a number of observable features, such as low dominant frequency, absence of high frequencies and dimming of reflections. We obtain the time-frequency distribution of seismic signals at different scales based on wavelet decomposition and try to analyse the response of high-frequency sections for the characterization of hydrocarbon reservoirs. We present a case study using multi-scale (dominant) frequency and multi-scale absorption, and demonstrate that the method is effective in recognizing a deep tight-sandstone gas reservoir. By this study, we can draw the conclusion that multi-scale frequency and absorption attributes may indicate the gassy areas in reservoirs, and we have obtained many good applications in the Sichuan basin of China.