中文摘要：

本文介绍了2．5维有限差分法的推导和计算过程，将它在轴对称井孔声场中的计算结果和用其他解析方法得到的结果进行了对比，得到了相当一致的结果。文中讨论分析了2．5维有限差分法应用于井孔声场计算中需注意的问题，并指出应用2.5维有限差分法可有效利用现有的微机资源解决一大类轴对称和非轴对称井孔声场计算问题。

英文摘要：

2.5 - D finite difference method was introduced and used in the simulating of wave propagation in borehole. The result of the 2.5 -D finite difference method for the case of an open well is compared with that of the well known real axis integration method, and this provides an accuracy check of our 2.5 -D finite difference code. The difficulties which should be overcome when 2.5 - D method used in borehole acoustic field simulating were studied. The most advantageous of this 2.5 -D method lies in that it can solve some kinds of 3 - dimensional acoustic field problems with small computer memory.