Abstract: The Neogene shallow water delta reservoirs of the Minghuazhen Formation in the southern Bohai Sea show a wide lobate distribution. The complex reservoir genesis and architecture and relatively low conventional reservoir characterization accuracy based on composite sandbody limit the understanding of remaining oil distribution and recovery in the middle-late development stage. The Sandbody 1167 of BZ28 Oilfield in the southern Bohai Sea was taken to separate the configuration unit based on the modern sedimentary evolution mode of shallow water delta. High-resolution seismic attribute, logging facies, horizontal well geo-steering, production history and other data were comprehensively used to separate the sandbody configuration step by step from the sedimentary lobes in composite river channel, distributary channel and distributary bar. Research indicates that the lateral shallow water delta reservoir in the study area shows a alternate distribution of distributary channel and distributary bar. The reservoir sedimentation is dominated by distributary bar, which is composed of vertical stacking between sedimentary lobe, low angle frontal accumulation and backflow degeneration. The distributary channel is a water channel with relatively small reservoir thickness. This research could provide certain guidance for the understanding of water flooding in the production.

Key words: shallow water delta, reservoir characterization, distributary bar, sedimentary lobe, architecture interface