利用正演模拟指导速度谱解释

在地震资料的处理中，速度分析是关键一环。在构造复杂断层发育的地区，受不同产状地层的影响，波场变化较大，反射波时距曲线已不是常规意义上的双曲线形态,加上低信噪比的因素，在速度谱上能量团往往比较分散，速度变化较大，常发生速度倒转，使处理人员很难把握速度的趋向。针对这一问题，探索了一种利用正演模型，生成CMP道集，再做速度分析的途径，从中找出了在特殊构造下的速度变化规律，增加了速度拾取的准确性。对复杂构造特征有代表性的逆掩断层进行探讨说明，利用模型正演指导速度谱解释的方法，可以提高速度谱的解释可靠性。

Velocity spectrum interpretation directed by using forward modeling

Velocity analysis is most important in seismic data processing. In area of complex geological structures and enriched faults, the time-distance equation of reflection is no longer a hyperbola. Energy gathering on velocity spectrum tends to scattering, and velocity changes rapidly or even reverses, which makes it difficulty for data processors to grasp the velocity change trend. To cope with this problem, we proposed to generate CMP gather using forward modeling to direct velocity analysis. This method was demonstrated by velocity analysis o-ver overthrust. Desired results have been achieved.