Numeric simulation in the relationship between low frequency shadow and reservoir characteristic
Abstract：In order to explore the appearance and characteristics of low-frequency shadow （LFS） at different thickness of reservoir and different depth of reflection interface beneath reservoir, a wave field extrapolation algorithm of a 3D diffusive and viscous wave equation （DVWE） in frequency wavenumber domain was proposed. Five different geological models with hydrocarbonbearing bed were designed and the seismic response of the models was simulated using DVWE, and the instantaneous spectral cecomposition was performed using the generalized S transform. The seismic response and its reflection energy variation with the frequency of each model were comparatively analyzed. The results reveal that LFS become more apparent when low Q in res- ervoir, greater diffusiveness and viscousness properties of fluid in porous media. LFS appeared at different depth under reservoir. At 8-12 Hz, the reservoir energy was a bright spot, and a strong LFS was shown beneath the reservoir, i.e. strong reservoir and bright shadow＂. As the frequency was 16-60 Hz, LFS was gradually attenuated until the shadow gone, while spectral energy of the reservoir wasstill relatively strong, i. e. strong reservoir and weakshadow＂.
Keywords：low-frequency shadownumerical simulationreservoir characteristicgas identifi-cationinstantaneous spectral decomposition
Publication Date：2011-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)