Abstract：Conventional methods of 3D seismic geometry design are based on the assumption of horizontal subsurface reflectors,which is not suitable for complex structure.Based on the previous research on two-dimensional problem,this paper develops a 3D target-oriented optimal geometry design method using the seismic illumination.This method uses the one-way Fourier finite-difference wave propagator to extrapolate plane wave sources from the target layer to the surface.By analyzing the wave energy distribution at the surface extrapolated from the target layer,the optimal shot positions for the target best illuminated can be determined.And finally,the imaging quality of the target or the shadow areas can be improved.In the numerical tests,seismic illumination and migration results based on the 3D SEG-EAGE salt model suggest that this 3D optimal geometry design method is effective and available.
