Application of Shallow Water Multiple Suppression Technology in Gentle Slope Zone of Lufeng 15 Depression in Pearl River Mouth Basin

JIA Liankai; QIU Xinwei; XIAO Zhangbo; ZHU Wenting; ZHAO Fang; HU Qiuhong; ZHAO Yue

doi:10.13512/j.hndz.2025.04.17

Abstract：The water depth in Lufeng Sag of the Pearl River Mouth Basin is relatively shallow and the terrain is relatively flat.Two sets of high-velocity limestone strata are widely developed in the Pearl River Formation in this area.The strong reflection coefficient interfaces formed by the strong impedance difference between the sea surface,seafloor,and limestone strata readily generate multiples with high energy.In addition,the short-period multiples formed in shallow water areas interfere with effective reflections,affecting shallow,medium,and deep strata,which significantly increases the difficulty of seismic interpretation.The unique geological characteristics of this area result in strong multiple energy and complex multiple types,making it difficult to effectively suppress them by conventional methods.Based on the geological characteristics of the area,this study takes the gentle slope zone of Lufeng 15 Depression in the eastern part of the basin as an example and adopts a targeted combination multiple suppression approach for shallow water areas.First,the Model Shallow Water Demultiple(MWD)method is used to suppress water-layer-related multiples,especially short-period multiples.Then,the 3D Surface Related Multiple Elimination(3D SRME)method is applied to suppress long-period multiples related to the sea surface,particularly those associated with the limestone interface,as well as some interbed multiples.Finally,the high-resolution Radon transform is applied on common reflection point gathers to suppress residual multiples.The results show that the combined MWD+3D SRME+Radon method can effectively suppress short-period water-layer multiples,long-period limestone-interface-related multiples,and some interbed multiples,significantly improving the signal-to-noise ratio and imaging quality of seismic data,and providing an important reference for areas with similar geological backgrounds.