Depositional System of the Sha1,2 Formation (Paleogene) in Laizhouwan Sag,Bohai Bay

The utilization the oil and gas bearing basin sedimentology's theory and the method,based on the massive core,the logging,the well logging and the seismic data analysis,the deposition system's type,the characteristic and the distributed rule of the Sha1,2 Formation(Paleogene) in Laizhouwan Sag,Bohai Bay has been verified.Laizhouwan Sag is one of the typical rift lacustrine basins(断陷湖盆) in the Bohai Gulf Basin,the fault boundary on the east,and onlap in the west,the braided river delta,fan delta and the lacustrine deposit system developed in the sag,but the braided river delta is predominate.The braided river delta system developed in the western,fan delta only developed in the eastern part nearby the basin margin rift and in the southern part nearby the basin margin actic region,and the scale is small.The braided river delta and the fan delta distribution area,developed high quality reservoir of oil gas,is the oil-gas exploration key area belt.