某油井的高压直管在试压作业后进行酸洗作业时发生泄漏。通过化学成分分析、壁厚测量、硬度测试、力学性能测试、金相检验、扫描电镜及能谱分析等方法，对该高压直管泄漏的原因进行了分析。结果表明：该高压直管内表面存在折叠缺陷是造成泄漏的主要原因；多次酸洗作业使高压直管的壁厚因腐蚀而明显减薄，承压能力降低，是造成泄漏的次要原因，两者共同作用导致高压直管最终泄漏。

The high pressure straight pipe in an oil well leaked during acid pickling after pressure test. The causes of leakage on high pressure straight pipe were analyzed by means of chemical composition analysis, wall thickness measurement, hardness test, mechanical property test, metallographic examination, SEM and EDS analysis. The results show that the folding defect on the inner surface of the straight pipe was the main reason for leakage. Multiple pickling operations had made the wall thickness of the high pressure straight pipe to be significantly thinned due to corrosion, and reduced the pressure bearing capacity, which was the secondary cause of leakage. The combination effect of the two causes led to the final leak of the high pressure straight pipe.