Abstract: By means of the acoustic source model of multiple receiving points from excessively long source distance and the numerical simulation computation of the acoustic full-wave in the borehole, the feasibility and method of using reflected wave to detect the transverse interface of the cylindrical multi-layered media were investigated. An array of full-wave curves of the cylindrical triple-layered fluid-solid-solid borehole system that is 30 m away was calculated, and the reflected wave from the interface far from the borehole was clearly shown, which agrees fairly well with the time-distance curve calculated by virtue of the theoretically derived equations of source distance-arrival time of reflected wave. Finally, a cross-section chart of the interfa ce time(depth) records after adjustment (without the influence of tube wave) was drawn, and the information of interfacefar away from the borehole (of in- phase axis) was clearly presented.

Key words: acoustic well, logging reflected wave, time (depth) cross-section chart