【摘要】 采用弹性波方程数值模拟和Zoeppritz方程解相结合的方式,研究了井间地震固-固界面上以及低速和高速夹层中弹性波场特征及传播规律。给出了井间地震弹性波的主要类型,其中包含一种特殊面波,该面波由激发井和接收井内的地层界面处产生的二次源形成,并说明了反射波以广角反射占优势;利用正演模拟记录对广角反射现象进行了分析,得出了在临界角处广角反射波的振幅、相位突变,极性反转,这与反射系数变为复数相对应;提出利用临界反射波特征和临界反射点位置来确定地层速度。震源在高速夹层中激发时,其中传播的弹性波场简单;而在低速夹层中,则弹性波场非常复杂。低速夹层中的导波存在明显的频散现象,其振幅和频率与低速层的速度和厚度密切相关。提出利用导波可以确定低速层的横向变化和连通性。更多还原

【Abstract】 Based on the combination of numerical simulation of the elastic wave equation with Zoeppritz equations,the authors studied characteristics and regularity of elastic wave propagation in solid-solid interface and high and low velocity interlayers between wells.The main types of elastic waves were classified,including a specific type of surface wave produced by secondary source formed in the interface between the source well and the receiver well.It is also found that the predominant reflection waves are wide angle refection.The authors analysed he wide angle reflection phenomena by forward simulation of seismic records and thus obtained the results of amplitude and phase sharp changes as well as polarity inversion of wide angle reflections at the critical angle point,corresponding to the change of the reflection coefficients into the complex numbers.Furthermore,the determination of layer velocities by reflection characteristics of the critical angle reflections and the reflection point was suggested.The elastic wave fields formed are simple when the source is located in the high velocity interlayer,whereas the elastic wave fields formed become complicated when the source is located in the low velocity interlayer.The guide waves show obvious dispersion when they are propagated in the low velocity interlayer and their amplitude and frequency are closely related to the velocity and thickness of the low velocity interlayer.The lateral changes and connectivity of the low velocity layer can be estimated by the guide waves.更多还原