Abstract: Based on the seismic reflection of fluvial reservoirs, using the spectrum decomposition technique by Discrete Fourier Transform in short window, this paper attains the object using the imaging feature of 4D time-frequency volume in frequency domain to predict the distribution of river channel sands, by which the spectrum decomposition data from 1st block of East-1 area in Dagang oilfield are applied to analysis of the distribution feature of fluvial channel in southern studied area with low well-control condition. The predicted results have been proved by drilling data.

Key words: short window, Discrete Fourier Transform, spectrum decomposition, fluvial channel sand, 4D time-frequency volume