问题的提出随着垂直地震剖面法的广泛应用,用它计算层速度的方法也日益增多。由于对射线路径的假设条件不同,因而导出了各种计算层速度的方法。其中以直达波直射线传播路径为假设条件的计算层速度方法用得较多。图1是井下接收点列中 A_1、A_2两个相邻接收点的直达波传播路线图。假设地下为均匀介质,激发点 B 离井口 A_0的距离为 d_K(d_K 尽量小),H_1、H_2分别为 A_1、A_2两点的深度,则 A_1、A_2两点之间的层速度可由下式求出 Proposed problem With the widespread application of vertical seismic section method, it is also used to calculate the velocity of the layer is also increasing. Due to the different assumptions of the ray paths, various methods of calculating the velocity of layers are derived. Among them, the method of computing layer velocity based on the assumption of direct wave propagation path is more used. Figure 1 shows the direct wave propagation path of two adjacent receiving points A_1 and A_2 in the downhole receiving point column. Assuming that the underground is a homogeneous medium, the distance between excitation point B and wellhead A_0 is d_K (d_K is as small as possible), and H_1 and H_2 are the depths of two points A_1 and A_2, respectively. Then, the layer velocity between A_1 and A_2 Out