Abstract:The paper presented a forward simulation method for wavefield continuation at shot point,which is characteristics of relative hi-fi waveform,high computational efficiency and appropriate for fluctuate surface:the wavefield at shot point makes continuation along the wave propagating direction;the technique of initial plane of wavefield continuation appropriate for fluctuate surface is used in computation,which is characterized by relative hi-fi waveform and without lateral stack.The basic ideas are as follows:①based on Huygen's principle,the downward continuation of wavefiled at shot point is started from the shot-point depth on fluctuate surface along the propagating direction of seismic wave layer by layer,the continued wavefield correlates with coefficient of interface and until to the deepest position;②upward continuation is carried out layer by layer,adds new wavefield of reflection at shot point produced at stage of downward continuation,and until to the position of spread on fluctuate surface,then correlation of wavefield at shot point with that at receiver point is carried out one by one,in which the synthetic seismogram of a spread is got after inverse Fourier Transform;③repeating abovementioned steps,the all shot record in the whole work area is got.The theoretical model test of steep mountain body and high-velocity lenticular body by using the method showed that the reflections and diffractions on the synthetic seismogram are very clear and without multiple,direct wave and other interference waves,the S/N is higher and prestack depth migration imaging of all shot records completely coincides with geologic model.
杨海生, 刘云生. 适合起伏地表的炮点波场延拓正演模拟[J]. 石油地球物理勘探, 2009, 44(2): 146-151.
Yang Hai-sheng, Liu Yun-sheng. Forward simulation of wavefield continuation at shot point appropriate for fluctuate surface. OGP, 2009, 44(2): 146-151.