Research On Converted Wave Static Correction Based For The Ocean Bottom Node On Wavefield Continuation

The problem of static correction has always been an important and difficult point in the seismic exploration process.For the Ocean Bottom Node(OBN)seismic exploration technology,it adopts the observation system that the source is excited on the sea surface and the receiver is received on the seabed,making the source It is not on the same plane as the receiver and has a large difference in elevation.In addition,for the converted wave,due to the low shear wave velocity,a large shear wave static correction amount is generated;therefore,the static correction of the shot point and the detection point of the undulating surface is a problem that must be solved.This paper studies a method of static correction of OBN converted waves based on the wave equation,which is based on the dynamic characteristics of seismic waves.First,a new transformed coordinate system needs to be re-established according to the function of the undulating surface.The detector is projected on the same horizontal plane,and its extension formula in the frequency domain is derived from the wave equation in the new coordinate system,and then the source and receiver are stepped in a certain step and the new extension formula is used.Select an appropriate datum plane to extend to a certain depth to get the data result after the static correction process is completed.In the research process,it is found that the most important thing is to perform coordinate transformation on the data,so that the wave number in the frequency domain and the spatial distance in the time domain can truly correspond to the Fourier transform pair;followed by the extension operator and extension in the extension process.Extension step selection.In this paper,the flat layer model of the OBN observation system is first selected for static correction processing using the written program,and then the selected reference plane is used as a forward inspection point to obtain a theoretical static corrected seismic record.By comparing the processed data with the theoretical data,Verify the feasibility and correctness of the written program;then establish the undulating model of the Ocean Bottom Node seismic OBN observation system,perform forward modeling to obtain seismic data,then statically correct the undulating seabed seismic data,and finally obtain the processed seismic data,Which appears as a pseudo-hyperbolic form in the seismic records;secondly,the selected reference plane is used as a new observation system to perform forward model again,and compare it with the processed data,and analyze the error.Finally,through the calculation of the model and the analysis of the data processing,it is proved that the static correction processing method of seabed seismic converted waves based on wave equation extension is feasible.