某输油管道腐蚀穿孔失效原因分析

Corrosion Perforation Failure Analysis of Oil Pipeline

为了研究某输油管道腐蚀穿孔的失效原因,对腐蚀穿孔管段进行了理化性能检测以及腐蚀产物分析。结果表明,管道腐蚀穿孔失效主要是由于管道内壁垢层下方发生严重局部腐蚀而造成。由于穿孔处管段位于管线下坡的低点处,且油管内介质流速很低,在输送过程中管内油水在穿孔处管段底部会发生分层,导致管段底部的管壁与水接触而发生较为严重的腐蚀;并且介质中的砂石颗粒也易于在该处沉积,砂石颗粒与腐蚀产物膜相互掺杂形成了较厚的垢层,垢层表面存在较多孔洞,有孔洞的垢层下方更容易发生局部腐蚀,从而导致管体腐蚀穿孔。

In order to study the failure causes of oil pipeline corrosion perforation, the physical and chemical properties and corrosion products of the corrosion perforation pipe section were tested. The results show that the failure of pipeline corrosion perforation is mainly caused by serious local corrosion under the scale layer on the inner wall of the pipeline. Because the pipe section at the perforation is located at the low point of the slope pipeline and the medium flow rate in the oil pipe is very slow,the oil and water in the pipe will be stratified at the bottom of the pipe section at the perforation during transportation, resulting in serious corrosion due to the contact between the pipe wall at the bottom of the pipe section and water. Moreover, the sand and stone particles in the medium are also easy to deposit here. The sand and stone particles and the corrosion product film are doped with each other to form a thicker scale layer. There are many holes on the surface of the scale layer, and local corrosion is more likely to occur below the scale layer with holes, resulting in corrosion perforation of the pipe body.