Abstract:

With the improvement of the exploration degree，exploration target of old oil fields towards the deep and shallow is one of the development directions in East China. Dolomite deposition of lateral stable spread not only shields the effective downwards propagation of the seismic signal, but also generates multiples in Biyang deep area. The speed and density of sand and shale are similar and the difference between their impedances is small in deep series of strata formation after intense compaction, so low SNR is caused,which affects the structure explanation and reservoir prediction. Based on forward modleling result of multiple asympatotic ray of model, the paper states the kinematic characteristics of multiples and provides bases for the choice of the methods of multiple suppression. The paper puts forwards a correlative processing method to improve the processing technology of the deep seismic reflecting quality at high impedance of dolomite in deep depression. Multiple removal and energy compensation by deletion fitting method are used in Biyang deep depression, which improves the SNR and resolution of the deep seismic processing data and gets a good exploration effect.

Key words: deep exploration, forward modeling, deletion fitting, multiple suppression, deep layer