倾斜层状介质结构折射波解释方法——射径法

INTERPRETATION TECHNIQUE FOR OBLIQUE LAYERED MEDIUM——THE RAYPATH TECHNIQUE

青岛海洋大学

本文根据折射波在倾斜层状介质中的传播规律,建立了多层倾斜界面结构中的折射波时距曲线方程式,并根据各层折射波时距曲线的截距时,视速度和第一层介质中的波速值这三个基本参量,采用递推方法,利用微机自动计算和绘制各界面折射波的下行波(临界入射波)滑行波和上行波(折射波)在层状介质中的传播路径。通过滑行波的射径可直接确定各折射面在剖面中的位置和产状,称这种解释方法为射径法。由于它能计算折射波在各层介质中传播路径的大小和方向,因而为进一步研究折射波在传播过程中的动力学特征提供了理论依据。 文章根据折射波在倾斜层状介质中的时距理论和射径解释方法,分别对四层和五层介质结构模型进行了正演计算和反演解释,给出了有关图表和完整的处理流程图。模型试验取得了很好的效果,表明该方法的理论是正确的,方法是可行的。

Based on the propagation rule of the refraction wave in the oblique layered medium, the refraction time-distance equation for multi-layered oblique interfaces was established. According to the following basic parameters: the intercept time of the refraction time-distance curve of each refractor, the apparent velocities corresponding to each curve and the wave-velocity in the first layer, the ray-paths of the down-going, the alongside-interface (in high-velocity medium), and the up-going refraction in layered medium could be automatically calculated and plotted by micro-computer with the recursive technique. In interpretation, the direct determination of the position and the occurrence of each refractor by the ray-path of the alongside-interface refraction is called THE RAY-PATH TECHNIQUE. Because of the raypath and its direction in each layer could be calculated with the technique recommended, it thus lays a foundation for the study of the dynamic characteristic of refraction in its propagation in theory.Based on the refraction time-distance equation for the oblique layered medium and with the aid of the raypath technique, the forward and the inverse calculation have been made for models of 4 and 5 layers. The charts concerned and the integrated flowchart were presented. Good results have been achieved from model experiments. It shows that the theory of the technique is right and proper and the way for its implementation is perfectly feasible.