【摘要】 在分析井中VSP地震观测系统特点的基础上,对观测到的地震波类型和特征作了阐释,分析了几种VSP模型(水平界面模型、倾斜界面模型、变偏移距模型、不同深度检波点模型)的射线追踪记录以及合成记录,利用射线追踪方法进行正演模拟,得到正演结果,并研究地震波的运动学特征。得出一些规律:钻孔穿过地层的数量等于合成记录上上行波和下行波的交点的数量;利用P波进行射线追踪和用转换波追踪其合成记录有差别,即转换波对VSP合成记录有影响;不同倾角的岩层对VSP上行波、下行波的走时特征和能量特征有影响;VSP合成记录的水平分量上会出现反极性现象,这与理论相一致。更多还原

【Abstract】 Based on analyzing the characteristics of borehole VSP observation system,the authors investigated the types and features of the observed seismic waves,analyzed ray-tracing and composite records of several VSP models(horizontal interface model,oblique interface model,meta-deviation distance model and detection point model),conducted forward modeling by using the ray-tracing method so as to obtain the forward result,and studied kinematic characteristics of the seismic wave.Some regularities have been detected: the number of the strata penetrated by the drill hole is equal to the number of intersecting points between the ascending waves and the descending waves in the composite record;there exist differences between the composite ray-tracing record obtained by utilizing P wave and that obtained by utilizing the transform wave,which shows that the transform wave has some influence on VSP composite record;strata of different dip angles have influence on travel-time features of ascending wave and descending wave as well as the energy characteristics of VSP;there exist reverse polarity phenomenon on the horizontal component of VSP composite record,which is consistent with the theoretical phase.更多还原