Delineation of shallow channel geometry and infill lithology using Spectral decomposition and seismic attributes: A case study from the North Sea Basin, Netherlands

Abstract. In the Southern North Sea, 3D seismic data had been widely acquired to explore for hydrocarbons, but interpretations of these datasets until now focus mainly on the deep exploration targets of the petroleum companies. Less attention is given to shallow sediments. But these sediments often contain channels that can serve as potential reservoir units. Thus the mapping and identification of these shallow channels and defining their infill lithology is important. In this study, seismic spectral decomposition technique has been used to delineate shallow thin channel geometry in a 3D seismic data acquired in the Dutch sector of the North Sea. The concurrent interpretation of curvature and coherence cubes with seismic facies analysis based on reflection terminations and geometry, amplitude and continuity enables the discrimination between shale versus sand filled channels. The results of the spectral decomposition show two distinct low sinuosity channel features in NNE–SSW direction but becomes diffuse towards the North. The strong negative curvature anomaly along the channels's axes observed in the most negative curvature attribute implies that the sediments within the channels have undergone more compaction. These strong negative curvature anomalies are interpreted to be due to differential compaction of shale filled channels.