复杂地形条件下地震速度提取方法及分析

THE METHOD FOR EXTRACTING VELOCITY UNDER THE COMPLEX TOPOGRAPHIC CONDITION AND ITS ANALYSIS

通过对典型地形起伏的６个水平均匀层状介质理论地质模型的速度谱计算和分析，阐明了在复杂地形条件下用常规水平基准面方法提取叠加速度，不仅达不到地震勘探对速度精度的要求，而且产生假的纵、横向变速规律。证明了采用滑动基准面〔１〕方法提取叠加速度，既可消除地形起伏的影响，又可满足地震勘探对速度精度的要求和如实反映地层速度。

Based on the calculation and analysis of the velocity spectra of the theoretical geological model for six horizontal homogeneous bedded media under the condition of typical topographic relief, this paper points out that the utilization of the conventional horizortal base level technique for extracting stacking velocity under the complex topographic condition fails to attain the precision of velocity and will produce false longitudinal and latitudinal velocity variation regularity. It is also demonstrated that the use of the slipping base level method to extract stacking velocity can not only eliminate the effect of topographic relief but also satisfy the velocity precision of seismic exploration. In addition, the method can reflect the real interval velocity.