Detection of low-frequency shadows based on instantaneous spectral analysis

In this paper, we describe the ISA technique which avoid windowing problems of conventional Fourier transform and can enhance frequency resolution of seismic data. By comparing ISA with FFT, we show some obvious advantages of ISA. Utilizing ISA, we can estimate reservoir and detect oil-gas by identifying low-frequency shadows beneath rich gas reservoirs, Research has proved detection of lowfrequency shadows is an effective assistant means to reservoir prediction and oil-gas detection.