埋地输油管道腐蚀缺陷分析及修复工艺

以东北输油管道为例,分析了埋地输油管线腐蚀特点及原因,认为管道的腐蚀主要是由于防腐层老化、剥离,导致出现阴极保护死区,该部位在土壤中氧浓差及细菌的作用下发生了电化学腐蚀;另外,管体表面膜不完整、阴保系统本身缺陷等也最终会加剧管道的腐蚀.提出了防腐层修复、管体补强(开挖技术如套袖补强、非开挖修复如内衬法等)的管道修复工艺要点及适用情况.

Analysis and Repair Technology of Corrosive Defect on Buried Oil Pipelines

The corrosion characteristics and reasons of pipelines were analyzed on the basis of finding out the corrosive condition(Northeast oil pipelines).It was considered that the main reason for pipelines corrosion was the aging and denudation anti-corrosive coating's,both of which lead to the skip area of cathodic protection.Electrochemical corrosion occurs in this area under the earth's oxygen differential concentration and bacteria.On the other hand,pipelines corrosion can be aggravated by imperfect surface film and defect of a cathodic protection system.Thus,the technical processes and applicability of repairing the anti-corrosive coatings,enhancing the pipeline strength(including ditching technology,such as sleeve enhancement,non-ditching repair such as inner lining technology) had been proposed,which are of a theoretical and practical value.