Research On S/N Ratio Increasing Of Wide-azimuth Acquired Seismic Data

Wide-azimuth seismic data refers to seismic data which are acquired with wide-azimuth geometry. Wide-azimuth geometry means that can get more complete information from underground in a wide area. Make sure the information from different azimuth are balanced. Achieve more accurate image when processed with full 3d program. Wide-azimuth seismic data processing technique is the important phase in wide-azimuth exploration. How to increase the S/N ratio of wide-azimuth acquired seismic data is one of the key step in wide-azimuth seismic data processing.Based on the Omega data processing software with PC-cluster machine, the research work have been carried out to increase S/N ratio, solve the problem of stacking velocity varying with azimuth and linear noise changing into non-linear at long-range offset.When seismic data are acquired with wide-azimuth geometry, ground-roll and refraction become totally non-linear in shot gather, which can not be separated from. primary reflection. In this text a new method was proposed. First separate the seismic data into several subset gather according their azimuth. Then in f-x domain transfer the large offset non-linear noise into linear in subset azimuth gather with coherent noise prediction. Finally by the difference with primary reflection in stacking velocity, coherency and energy, attenuates the noise. Which fulfill the purpose of attenuating the non-linear noise and making no harm to frequency width of the primary reflection in the same time.As to the problem of stacking velocity varying with different azimuth a anisotropic NMO was adopted. Further more on the Omega and Omega2 platform, the interactive workflow to build up the anisotropic NMOηfield was developed. So the data processing accuracy can be raised, the noise can be attenuated by anisotropic NMO and residual static correction iteration.