The presentation at Integrity 2020 is now online on MetriCorr’s Youtube channel
MetriCorr’s presentation focuses on risk assessment, mitigation and continuous monitoring of cathodic protection and AC corrosion. In addition, several field case studies are presented to illustrate the most cost-effective method of AC corrosion mitigation.
Electromagnetic interference from above ground high voltage transmission lines causes an AC voltage to be induced in paralleled buried pipelines. Besides being a safety concern to pipeline operators, the induced AC voltage poses a risk of causing AC corrosion of the pipeline steel, despite the application of cathodic protection. AC corrosion is known to be developing at small coating defects and can reach corrosion rates in excess of 10 mm/year.
To verify that the pipeline integrity is not compromised while maintaining this balance between AC interference and cathodic protection level, a remote monitoring system that continuously measures the corrosion rate as well as all relevant electrical fingerprints is applied. The measured parameters include:
- Corrosion rate (ER)
- On potential
- Off potential
- IR-free potential
- DC current density
- AC voltage
- AC current density
- Spread resistance
