Multi-wave Seismic Imaging Technology And Application

Seismic imaging technology has many contents,prestack noise attenuation,amplitude compensation,deconvolution,static correction,migration and other conventional post stack processing technology,also has the prestack time migration,prestack depth migration,anisotropic prestack depth migration,and the azimuthal anisotropy correction processing analysis combined with geological characteristics,and so on.Multiwave seismic data processing including non-converted wave(eg.P-wave,S-wave)imaging and converted wave(eg.PS-wave)imaging.This paper studies the non-converted wave imaging technology,as PP wave as the representative discussed.In petroleum geological exploration,P-wave seismic exploration method has been continuously improved,the development from acquisition to processing technology.In the denoising technology for different types of noise with various methods: to eliminate regular noise with prediction,take statistics for irregular noise suppression.The P-wave amplitude compensation technology are not only on the distance compensation in the wave propagation,but also there are consistency compensation for surface differences,and consider the anti-Q absorption compensation stratigraphic absorption.The deconvolution technology not only can improve the technology of surface consistent deconvolution of wavelet coherence,but also improve the resolution of predictive deconvolution technique.P-wave static correction technology developed a lot,by the picking of first arrival time,refraction wave static correction based on refraction model,also has a static correction method based on the model of diving wave tomography,using reflection of a variety of residual static correction method,the static correction technique is beneficial to solve problem of the weathered layer and low velocity layer.Migration technology has many methods,poststack migration technology is very mature,prestack migration technology also developed a lot,by migration,we can converge the diffraction wave and move the reflected wave to real space position.In the parameter analysis of migration,gradual development of imaging anisotropy,the model considered is more complicated and complex geological features in order to more realistic,the anisotropic prestack depth migration processing has gradually become the general process of P-wave processing.On S-wave,the basic processing technology is suitable.Study on processing converted wave imaging,noticed thai the shot point and the receiver point is not interchangeable,resulting in some technical methods of P-wave processing are not suitable for the converted wave processing.Therefore,after the multiwave seismic data separation,converted wave processing technology developed some specific technology,the methods were different from the P-wave.In the time domain,the calculation of common conversion point(CCP),the converted wave velocity analysis and the normal time moveout(PS-NMO)were completely different with P-wave processing which were CMP,P-wave velocity analysis and PP-NMO.Because of the shot point using the P-wave correction and the detection point using S-wave statics,the first arrival time methods is difficult to use in converted wave static correction.Generally larger than the P-wave,the S-wave statics calculation is complex.This is also one of the factors restricting the development of the converted wave,and multiwave exploration often selected the area where surface structure is simple.From the common conversion point stack imaging to converted wave prestack time migration imaging,the calculated and converted wave migration problems solved.But the anisotropic problem is more prominent in PS-wave than in P-wave,so we should consider a more complex model.At present the converted wave prestack migration technology has a lot of development from the isotropic prestack time migration to the anisotropic prestack time migration based on VTI model.The azimuth anisotropy analysis of HTI model correction,promote the application in shear wave splitting of crack in features,combined with the geological research has been developed;The converted wave depth domain imaging technology,reference P-wave method,also developed a lot.In the converted wave prestack depth migration imaging,velocity modeling in depth domain is highlighted,since the establishment of calculating model and anisotropic converted wave migration velocity field is complex difficult,so the modeling is still a very time-consuming work,which restricts the development of depth migration of converted wave pre stack.Firstly,this paper studies the techniques in multi-wave seismic data processing and gives a summary techniques which mentioned above,from the two aspects of the time domain and depth domain.Secondly,combined with the model data,the azimuth anisotropy is concerned with correction and prestack depth migration module is tested.Then we put forward the general process of land multiwave seismic data processing flows.At last,the application of the method was verified by the application results in a certain block of Tarim Basin.