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多次波深度成像是一种叠前深度偏移方法,它是将多次波作为更准确的边界成图和振幅恢复的有效信号。这一思路与基于模型的多次波压制技术和逆时深度偏移有着部分的联系。常规的逆时偏移是使用计算所记录地震道和射线追踪的反射波传播的双程波动方程,或者是使用计算直达波旅行时的程函方程(激励时间成像原理),因而逆时偏移与大多数其他的只需一次反射波的单程波动方程方法或射线追踪偏移方法大致相同。因为如果不减弱一次波就几乎不可能衰减多次波,所以需要寻求一种在资料处理中建设性地使用多次波而不是想着去破坏它们的方法。此外,如果把一个双程全波动方程用于偏移中,那么多次波和其他类型的非反射波就能加强边界成像和振幅恢复。新方法通过有限差分技术解出了波在正向和反向方向上传播的双程波动方程。因此,它可考虑所有类型的声波,例如反射(一次波和多次波)、折射、绕射、透射波和这些波的任意组合。 在成像过程中,所有这些不同类型波场的衰减都发生在生成或改变它们的边界上。这一成像过程经过了四个主要步骤。首先,利用双程标量全波动方程使源函数(子波)从震源位置向所有方向正向推进;其次,用双程标量全波动方程使炮点道集中的记录道从全部检波器点向所有方向反向进展;然后,对正向和反向传播波场进
Multiple Wave Depth Imaging is a prestack depth migration method that uses multiples as effective signals for more accurate boundary mapping and amplitude recovery. This idea is partly linked to model-based multiples suppression and inverse time-depth migration. Conventional inverse time migration is the use of a two-way wave equation that calculates the propagation of reflected waves from recorded seismic traces and ray traces, or the equation of the equation (excitation time imaging principle) used to calculate the travel of a direct wave, thus counter-clockwise shifting This is roughly the same as most other one-way wave equation methods or ray tracing offsets that require only one reflection. Because it is almost impossible to attenuate multiples without destroying the primary wave, there is a need to find a way to constructively use multiple waves in data processing rather than destroying them. In addition, if a two-pass full-wave equation is used in the offset, multiples and other types of non-reflected waves enhance the boundary imaging and amplitude recovery. The new method solves the two-way wave equation of the wave propagation in the forward and reverse directions by the finite difference technique. Therefore, it can consider all types of acoustic waves, such as reflections (primary and multiple), refraction, diffraction, transmitted waves, and any combination of these waves. During the imaging process, the attenuation of all these different types of wavefields occurs on the boundaries that generate or change them. This imaging process goes through four main steps. Firstly, using the two-way scalar full-wave equation, the source function (wavelet) is positively forward from all the sources in all directions. Secondly, using the two-way scalar full-wave equation, The direction of the reverse progress; Then, for the forward and reverse propagation wave field into