Research On Seismic Scattering Wave Imaging Method Based On Equivalent Offset

With the increase of the country's investment in major infrastructure construction,more and more emphasis has been placed on geological exploration.Conventional seismic exploration methods use multiple covered reflection wave methods for data analysis and processing.This method is affected by the dip angle of the stratum interface,which makes the geophysical exploration results greatly different from the physical stratum structure.Therefore,based on the principle of equivalent offset,this thesis studies the method of seismic scattering wave imaging.At the same time,the C# language was used to design the scattering wave data processing and imaging software on the.NET platform.In addition,simulation verification is completed and the imaging experiments are performed by using the geophysical data collected from the project site.The results prove that the design requirements are met.The main research contents of this thesis are as follows:(1)According to the mechanism of the scattering phenomenon produced by the seismic waves propagation in the stratum,the signal characteristics of the seismic scattered wave signals are studied.Through the analysis of time-frequency characteristics,power spectrum and frequency spectrum characteristics,the frequency and energy of the scattered waves are observed to vary with the size of the scatterer and the law of decreasing amplitude and dominant frequency are obtained.(2)The scattering wave propagation model and observation model are analyzed.Based on this,scattering wave imaging methods are studied.(3)Based on seismic scattering wave imaging method,the C# language is used to process the scattering wave data and design imaging software,which realizes the collection of common scattering point gathers,the analysis of scattered wave velocity,and the imaging function.(4)In order to verify the scattering wave imaging method and software functions,a forward modeling simulation experiment is performed.The processing results are basically consistent with the preset model.At the same time,the geophysical prospecting data carried out on the project site is used to analyze the imaging experiments and the results show that the geophysical requirements are met.After simulation and actual geophysical data analysis,the research methods and software designed in this thesis improve the imaging quality of geological sections and solve exploration problems such as large dip angle structures and faults.