The Research Of Seismic Data Wave Equation Datuming In Southern Marine Facies

It has been 50 years that our country spent on the seismic prospecting of southern marine facies carbonatite exploratory areas, which indicates the southern marine layer is a large potential oil area. There are many characteristics for the southern marine area, for instance, the surface elevation of these areas changes sharply, the high transmition speed of near surface, the lithological characters complication of the surface, which brings difficulties for acquisition, processing and interpretation of oil and gas exploration. The problems are reflected on three main aspects: firstly, topographic relief is a serious hinder for statics correction; secondly, there are different kinds of interference waves exist on the high velocity layer; thirdly, the complicated near surface velocity structure and the topography affect the subsurface reflected wave obviously and even seriously. The paper, based on the researches of southern marine areas and the methods of datum static correction of the wave equation, is instructive to seismic data processing and imaging under the complicated geological conditions.On the base of analysis of the southern marine area features, the seismic and geological problems, this paper analyses various kinds of wave equation surface correction methods and the problems. The finite difference method based on the wave equation carries out the numerical simulation algorithm of the high finite difference surface model, and test and verify the forward modeling algorithm. It supplies the basis of the studying the effects of the complex surface on seismic field. It also carries out the forward modeling using the model that is build according to the real data. And it provides the theoretical foundation for the wave equation datum static correction.This paper introduces the reverse-time extrapolation into the datum static correction method when we investigate the various kinds of wave equation datum extrapolation method. It applies reverse-time extrapolation with wave equation on seismic wave field on shot gather, inspecting the reference surface directly, to eliminate the influence of surface elevation and low-depression velocity layers on underground wave field, and finally corrects the reference surface of marine seismic data.The analysis of the theoretical model, the standard or model of marine carbonatite exploratory area and the corrected results of real data manifest that, the effects of wave equation reverse-time datuming correction on jetlag and energy of seismic wave travel which is caused by surface medium and surface structure is relatively good. Therefore it can be used to process the real seismic data and provide a good original data for the seismic imagining.