Application On Kirchhoff Integral Method Prestack Depth Migration-3D Salt Dome Imaging

Depth migration method can be divided into ray theory method and wave equation method.Gaussian Beam migration method improved on ray theory has higher computational efficiency and imaging precision.Reverse-time migration based on two-way wave equation attracts much more attention because of its high imaging precision,although it needs more internal memory,cannot adapt to non-regular grid,and rely much on the accuracy of velocity model.These limit its practical application.Kirchhoff PSDM based on ray theory can image on complex geological structural interpretation because of its more flexible and higher computational efficiency,so that this method have precise image on the salt dome and provide high resolution profiles for interpretation.The main contents of this paper are: seismic data processing,depth velocity modeling and prestack depth migration.In the aspect of seismic data processing,we use Geo East software to get prestack time section and RMS velocity.In the aspect of depth velocity modeling,we use DIVA software to get precise velocity model.In the aspect of depth migration,we apply 3 different prestack depth migration methods mentioned above on seismic data and numerical data in order to improve imaging precision of Mexico salt structure.In the aspect of seismic data,make contrast and analyze imaging result of 3 different methods.In the aspect of numerical data,test on dependence on velocity model.By comparison and analysis of the result,we find that Kirchhoff method has the highest resolution.