In order to investigate the acoustic locating method for down-hole tubing leakage for gas wells , a locating model which is suitable for single-point and multi-point leakage was presented on the basis of analyzing the propagation mode of leakage acoustic wave in the annulus .The method of extracted the characteristic time , that were based on the auto-correlation analysis of tubing leakage signals , was proposed after analyzing the characteristics of tubing leakage waves .By using the self-made experimental system , a series of experiments under single-point and multi-point leak positions were conducted .The characteristic time in each experiment was extracted , and the acoustic velocity in annulus was calculated , based which the leak positions were calculated and contrasted which the real values .The results indicate that the proposed model can be used to locate the single-point and multi-point leakage for down-hole tubing , and the absolute maximum error is 1.54％.It is characteristic time and acoustic velocity that are critical for locating down -hole leakage using this method .By using auto-cor-relation analysis of acoustic signals acquired at annulus top can extracted the characteristic time effectively .%为了探究气井井下油管泄漏地面声波定位方法,在分析油管泄漏声波在环空中传播模式的基础上,提出了井下油管单点及多点泄漏地面声波定位模型;分析了油管泄漏声波特征,并提出了基于自相关分析的油管泄漏声波信号特征时间提取方法;利用自主设计的室内实验系统开展了单点及多点泄漏工况下油管泄漏声波定位实验,提取了各工况下的特征时间,计算环空声速及泄漏点位置,并与真实泄漏位置对比分析.研究结果表明:所提出的模型能够很好的实现油管单点多点泄漏定位,实验中定位误差的绝对值最大为1.54％;利用该方法定位的重点是获取特征时间及环空声速;对环空顶部采集声波信号的自相关分析可以有效提取出定位所需的特征时间.
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