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.