Research On The Method Of Directional Deconvolation For Air Gun Array

In marine seismic exploration,air gun array is widely used to excite source signature.The array size is comparable with the seismic wave length,thus,its signature is dependent on the direction of seismic wave propagation,which means that the signature and its spectrum varies both with take-off angle and azimuth.This paper discusses the formation mechanism and numerical simulation method of the array's farfield signature.Based on this,analyses the directivity of air gun array and its effects on seismic data processing and AVO analysis using an actual array.The destination of directional deconvolation is correcting the wavelet in different incident angle to a certain incident angle.The ordinary directional deconvolation methods,such as the deconvolation conducting in ?-p and F-K domain,have some disadvantages,e.g.large computation,poor outcome and practicability.Through the analysis on array,we derives that the directional effect on wavelet makes the seismic record nonstationary both in depth and offset directions,therefore,a directional deconvolation method based on nonstationary inversion is proposed.The seismic recorder influenced by directivity can be considered as the convolution of the seismic recorder without directivity and directional response,so the seismic recorder eliminated directivity can be obtained using inversion method after calculating the directional response.Through model experiments,this method is proved efficient and practicable.Eliminating the effect of air gun directivity can fully take the advantages of the property that air gun wave can be simulated,and look for the new theory support and breakthrough direction for the marine seismic exploration.