Wave Field Separation Technique Research Of Multi-wave Seismic Exploration Data

As a new method of seismic exploration, multi-wave and multi-component seismic exploration has many excellent features. The underground wave field recorded information of multi-wave and multi-component seismic exploration is rich, which provides a great help for our better understanding of the nature underground media but brings the difficulty for processing and interpreting the seismic data. The longitudinal wave and transverse wave mix with each other in the multi-wave and multi-component seismic exploration data, need to separate them. Wave field separation has become an important step in multi-wave and multi-component seismic data processing. There are many wave field separation methods in theory andτ-p transform has some advantages in many wave field separation methods.This paper describes the basic principles ofτ-p transform in brief. how to use computer to realizeτ-p transform,the paper introduces the methods of realizingτ-p transform respectively at the time-space domain,the frequency-wavenumber domain and the frequency domain which use least squares inversion method. At the same time,the paper does a simple comparative analysis for the various methods. The paper deducts the kinematic characteristics of the various waves at theτ-p domain and verifies the deduction results on the computer. Aiming at the situation when offset is shorter than interface depth in seismic exploration, the paper presents using the parabolic equation to instead of the P-P wave and P-SV wave theroy time-distance curve equation approximately and does a theoretical analysis for the approximate alternative process. Meanwhile, the paper performs a wave field separation experiment with usingτ-p transform to separate the theoretical synthesis P-SV wave from P-P wave which have the parabolic time-distance curve equation.If we useτ-p transform directly to separate the P-SV wave from P-P wave which have the parabolic time-distance curve equation,the separate result is not well.This paper analyse the reason why the separate result is not well.Aiming at the analysis result,the paper presents a method for separating the P-SV wave from P-P wave by coordinate stretchτ-p transform which base on the parabolic equation.The basic principle of this method,wave field separation process and its implementation on the computer has been discussed in the paper.This paper performs a wave field separation experiment for the method.Finally, the paper introduces the basic principle of the parabolic Radon transform and its implementation process on the computer. The paper make an experiment on using the parabolic Radon transform to separate P-SV wave from P-P wave and analyse the reason why the energy divergence phenomenon appears in the parabolic Radon transform result during the experiment process.In order to eliminate the divergent energy impacting on the separation of P-P wave and P-SV wave,the paper adds the multi-channel correlation algorithm to the process of parabolic Radon transform and presents a new method that associates the parabolic Radon transform with multi-channel correlation. The paper describes the method of theory and its implementation in detail. At last, the paper makes an experiment on using the method to separate P-SV wave from P-P wave.