Abstract：The primary reflection waves recorded in the receiver point with same depth are not double times of first arrivals at the point because of layer dipping in zero-offset VSP data processing,making the reflection waves on upgoing wave two-way time aligned sections be not truly aligned and corridor stack appear errors.The larger the layer dip,the larger the errors.Starting from the surveying pattern of zero-offset VSP,the paper analyzed the influence of dip of bed interface on the correctness of reflection event position on corridor stack section and frequency of poststack reflection event and analyzed the formula used for analyzing layer dip and DMO correction of corridor stack.On that basis,the paper presented an improved corridor stack method and wrote software used for interactive analysis of layer dip at the same time,which is tested and processed by model data and practical data respectively and proved the effectiveness of the method.
