THE APPLICATION OF SPECTRAL DECOMPOSITION TECHNOLOGY TO THE LOWER CRETACEOUS RESERVOIRS PREDICTION IN EASTERN DEPRESSION OF THE NORTH YELLOW SEA

A block in the eastern depression of the north Yellow Sea is selected as the case for application of spectral decomposition techniques to the prediction of lower Cretaceous reservoirs and lithologic traps. The block is developed on the slope of a fan-delta facies. The sandstone reservoirs are thin in thickness and changing greatly in lateral direction. It is difficult to find favorable reservoir traps by conventional seismic attributes and seismic impedance inversion. According to the characteristic of reservoirs in this area, we used the continuous wavelet transform(CWT) method for generating tuning volume and discrete frequency energy volume. Combined with seismic attribute and horizontal slice technology, we made sandbody description and the study of reservoirs lateral variation. The prediction was fit with the actual drilling data, and could be used to delineate the distribution of sandbodies and their sources.