试片断电电位测量方法及影响因素

1. 中国石油管道科技研究中心· 油气管道输送安全国家工程实验室;2. 中国石油西南管道兰成渝输油分公司;3. 中国石油管道公司锦郑管道运行筹备组

埋地管道;阴极保护;试片;极化;断电电位

Measurement methods and influence factors of coupon off-potential
ZHAO Jun1, LIU Chunliang2, XU Huatian1, LIU Guohao1, YANG Miao3, ZHANG Yifeng3, WANG Jianwei3

1. PetroChina Pipeline R & D Center//National Engineering Laboratory for Pipeline Safety;2. PetroChina Southwest Pipeline Company Lanzhou-Chengdu-Chongqing Oil Transmission Branch;3. PetroChina Jinzhou-Zhengzhou Pipeline Operation Preparatory Group

buried pipeline, cathodic protection, coupon, polarization, off-potential

DOI: 10.6047/j.issn.1000-8241.2020.04.012

备注

试片断电法是一种评价埋地管道阴极保护有效性的快捷方式。随着管道阴极保护日常管理对管道断电电位测试需求的增加,中国正逐步实施试片断电法,但是试片断电法的使用还存在诸多不确定因素,如试片的极化稳定时间、试片面积及形状的选择等。通过现场试片极化试验,研究了试片断电电位的测量方法和影响因素。结果 表明:面积不同的试片极化15 min 后,趋于稳定的断电电位也不同,试片面积越小,电位越负;长方形试片较圆形试片的电位偏负一些;埋深较深的试片较埋深浅的试片断电电位偏负,但差别不大。最后对试片断电法在实际工程中的应用提出了建议。(图3表2,参[20]

Coupon instant-disconnect method is an efficient way to evaluate the effectiveness of cathodic protection forburied pipelines. With the increasing measurement demand for pipeline off-potential in the daily management of pipelinecathodic protection, the coupon instant-disconnect method is gradually implemented in China. However, there are stillmany uncertain factors in the use of the coupon current interruption method, such as the polarization stabilization time andthe selection of the coupon size and shape, etc. Through the coupon polarization test on site, the measurement methodsand influence factors of the coupon instant-disconnect potential were studied. The results show that the stabilizing instantdisconnectpotentials are different after 15-minute polarization for these coupons with different areas, i.e. the smaller thecoupon is, the more negative the potential will be. The potential of rectangular coupons is rather more negative than that ofcircular coupons. The potential of the coupon with deep buried depth is slightly more negative than that of the coupon withshallow depth despite the tiny difference. Finally, some suggestions on the application of coupon instant-disconnect methodin engineering were put forward. (3 Figures, 2 Tables, 20 References)

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