探讨了用零偏移距三分量VSP数据中的下行P-SV转换横波,求取厚度相当于VSP采集点距的地层横波速度。从井下检波器方位校正得到横向垂直分量,对其二维谱中各类波的能量和特点进行分析,通过二维滤波得到信噪比较高的下行转换横波,选取振幅较强的同相轴提取波至时间,获取了横波速度及泊松比。结果表明,即使是零偏移距VSP数据,只要其上有明显可见的转换横波,也能以采集点距的量级计算横波层速度。 This paper discusses the conversion of shear wave from the downlink P-SV in the three-component zero-offset VSP data to obtain the shear-wave velocity of the formation whose thickness corresponds to the VSP acquisition pitch. The transverse vertical component is obtained from the azimuth correction of the downhole geophone, and the energy and characteristics of each wave in the two-dimensional spectrum are analyzed. The two-dimensional filter is used to obtain the down-converted shear wave with high signal-to-noise ratio. Wave to time, access to the shear wave velocity and Poisson’s ratio. The results show that even with zero-offset VSP data, the shear-wave velocity can be calculated on the order of acquisition pitch as long as there is a clearly visible converted shear wave on it.