【摘要】 针对常规波动方程叠前时间偏移成像不能考虑速度的横向变化,尤其是强横向变化的不足,通过借助波动方程叠前深度偏移成像的概念,提出了一种能够考虑时间域速度横向变化的波动方程叠前时间偏移成像方法.导出了沿时间方向递推传播的时间域单程波广义屏波场传播算子,建立了用时间域单程波广义屏波场传播算子对共炮道集地震数据中的震源波场和观测波场分别进行时间正向外推和时间反向外推的广义屏叠前时间偏移成像算法.通过在国际标准的二维Marmousi模型和实际三维VSP(vertical seismic profile)地震数据的偏移成像试验,验证了该方法的正确性和对速度强横向变化的适应性.更多还原

【Abstract】 Aiming at the problem trat the conventional wave equation prestack time migration cannot take into account lateral variations of velocity,especially the strong lateral variations.Through borrowing the concept of wave equation prestack depth migration,a wave equation prestack time migration method was proposed,which takes into account the lateral variations of velocity in time domain.A generalized screen wavefield propagator,which recursively propagates along the time direction,was derived in time domain.A prestack time migration algorithm base on the generalized screen wavefield propagator was established by using the time domain one-way wave generalized screen wavefield propagator for propagating the source wavefield and the recorded wavefield along the forward and the reverse time direction,respectively.The tests of the wave equation prestack time migration on the international standard 2D Marmousi model and a real 3D VSP seismic data demonstrated its validity and applicability to the lateral variations of velocity.更多还原