摘要
我国一般采用多频管中电流法(RD400-PCM检测仪)对长输管道防腐层破损点进行检测定位,检测结果准确率达到100%;对管体壁厚的检测一般采用超声波检测技术,其精度要高于漏磁检测技术,点蚀达到5 mm2,10%管道壁厚的腐蚀量均能定量检测。埋地管道土壤环境评价指标包括土壤的电阻率、氧化还原电位、p H值、土壤含盐量以及含水量,根据各项指标确定了管道腐蚀级别,土壤含水量小于10%为宜,否则土壤对管道的腐蚀速率变大。将上述腐蚀检测体系在长庆油田某14 km的长输管道上进行了应用,结果表明:长输管道防腐层整体质量较好,管体腐蚀较为严重,其中坪五转外输腐蚀剩余管道壁厚最小,为3.81 mm,较大部分管线剩余壁厚均在4.31 mm左右。结合土壤环境,对使用年限较长的管道进行了更换,对有腐蚀现象的管段进行了维护,以延长管道使用寿命,降低长输管道运行风险。
Generally using multi- frequency tube in our country in current method（RD400-PCM detector） to test the coating damage point positioning,test result accuracy by100%; Detection of pipe wall thickness generally uses the ultrasonic testing technology, its precision is higher than magnetic flux leakage detection technology, achieve 5 mm2 pitting,10% amount of corrosion of pipe wall thickness can quantitative detection. Buried pipeline soil environmental evaluation index including soil resistivity,redox potential,p H value,soil salt content and water content, according to the size of the indicators to determine the level of pipeline corrosion, soil moisture content was less than 10% advisable, otherwise the soil corrosion rate of pipeline will increase.Then the corrosion inspection system application on a14 km long distance pipeline in Changqing oil field,result shows that long-distance pipeline anticorrosive coating is in a good quality, the pipe body corrosion is more serious, which turn flat five transmission corrosion remaining minimum of pipe wall thickness,3.81 mm, with most of the pipeline residual wall thickness is 4.31 mm or so, combined with the soil environment,to use fixed number of year long pipeline replacement,with corrosion phenomenon of section for maintenance,prolong the service life of pipeline,reduce the risk of longdistance pipeline operation.
出处
《油气田地面工程》
2016年第3期72-74,共3页
Oil-Gas Field Surface Engineering
关键词
长输管道
腐蚀
检测
剩余强度
评价
long-distance pipeline
corrosion
detection
residual strength
evaluation
