Research On Multiple Attenuation Method Based On CL-SRME

In the field of oil and gas exploration,the seismic imaging methods are mostly based on the assumption that seismic data contains only primary reflected wave energy.Therefore,in the process of seismic data processing,multiple is usually regarded as coherent noise which affects the accuracy of seismic data processing and interpretation,so the research on multiple attenuation method has been an important research direction in the field of geophysics.Since surface-related multiple is the most developed type of multiple in seismic exploration,especially in marine seismic exploration,it is necessary to study the attenuation methods of surface-related multiple.At present,the highly accurate and widely used surface-related multiple attenuation method at home and abroad is the feedback iteration method which is based on wave equation.This method takes the original seismic data as the predictor and does not need other prior conditions.It can realize the high-precision surface-related multiple attenuation driven by data.This paper focuses on the CL-SRME which is a kind of feedback iteration method.Firstly,the basic knowledge of multiple is reviewed,and the commonly used multiple attenuation methods are simply summarized.Then the WRW model of seismic wave is briefly analyzed,and the theoretical basis of feedback iteration method,feedback iteration model,is deduced.Through the analysis of three kinds of surface-related multiple attenuation methods,which are SRME,multiple attenuation method in inverse data domain and EPSI,developed on the basis of the feedback iteration model,it can be seen that the adaptive subtraction process of SRME,the matrix inversion of inverse data domain method and the multi-parameter inversion and sparsity assumption of EPSI all have some problems.CL-SRME,which was developed later,uses a wave form direct inversion method to suppress surface-related multiple,which avoids the insufficiency of the former three methods.It has the advantages of higher attenuation accuracy of surface-related multiple(especially when the primary wave interferes with surface-related multiple),no matrix inversion operation,fewer inversion parameters and wider application range.Based on the research of 2D CL-SRME method theory,deduced the 3D CL-SRME formula.Compared with the classical SRME method of simple model trial result,it is shown that the CL-SRME method can retain the energy of the primary wave more accurately in the process of surface-related multiple attenuation under the condition that the primary wave and multiple wave intersect in axis.The effectiveness and practicability of CL-SRME method are verified by using CL-SRME for complex models.Through the calculation results of 3D model data,the feasibility of CL-SRME for surface-related multiple suppression of 3D data is verified.