Abstract:

Fluvial sandstone reservoirs are common in continental fault depressions.They are characterized by vertical alternating of sandstone and mudstone and lateral rapid change of lithofacies caused by frequent river diversion.These features lead to discrete seismic reflection.This,in addition to the limitation of seismic resolution,increases the difficulty of reservoir prediction.Taking the study area in the central Jizhong Depression of the Bohai Bay Basin as an example,we studied fine seismic interpretation based on accurate horizon calibration and isochronous stratigraphic correlation.Based on that,we optimized extraction of seismic attributes and built up 3D visualization model.Frequency tuning for thin layers was performed and the results of frequency division were used to predict river channel distribution in plane.We also set up rational geological models and performed pseudo-sonic inversion with optimized parameters to obtain high-precise reservoir prediction results.

Key words: tuning frequency, seismic property, seismic inversion, reservoir prediction, channel sand, Jizhong Depression, Bohai Bay Basin