scholarly journals Experimental Study on the Influence of AC Stray Current on the Cathodic Protection of Buried Pipe

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Qingmiao Ding ◽  
Yueming Fan
Keyword(s):  
Experimental Study ◽  
Cathodic Protection ◽  
Comprehensive Analysis ◽  
Stray Current ◽  
Buried Pipe ◽  
Ir Drop ◽  
Threshold Length ◽  
Protection Potential ◽  
Ground Potential ◽  
Coating Crack

The size of the damaged area of the coating and its position on the pipeline impacted the cathodic protection potential, and there was a damaged area of the greatest impact value. When damaged area was 300 mm2, the IR drop was the largest, and this situation could easily lead to inadequate protection; when the parallel spacing between pipeline and interference source was unchanged, the measured value curves of cathodic protection potential presented “U” shaped trend with the increasing stray current interference intensity. Under certain parallel spacing between pipeline and interference source, high alternating stray current intensity would cause serious negative offsets, so that the overprotection of the pipeline occurred, and make the coating crack; there was a parallel threshold length. When less than the threshold, the pipe-ground potential increases rapidly with the parallel length increasing. In order to judge whether a pipeline was interference by AC stray current and the risk of stray current corrosion, we should make a comprehensive analysis of the cathodic protection energizing potential, the switch-off potential, AC pipe-soil potential, IR drops, and so on.

Research and Application of Portable Real Protection Potential Measurement System of Buried Steel Pipeline

2012 ◽  
Vol 605-607 ◽  
pp. 1042-1045
Author(s):  
Xue Fen Zhao
Keyword(s):  
Reference Electrode ◽  
Buried Pipeline ◽  
Stray Current ◽  
Potential Measurement ◽  
Ir Drop ◽  
Surface Data ◽  
Electrode Method ◽  
Protection Potential ◽  
Data Acquisition Unit ◽  
Ground Potential

The measurement of pipeline to ground potential is the most common method to evaluate protection condition of buried pipeline. For the old pipeline, pipeline to ground potential measured with surface reference electrode method or reference electrode method close to pipeline usually is not the real protection potential of buried pipeline due to presence of an IR drop and/or stray current interference. A portable real protection potential measurement system combining the polarized probe with the portable surface data acquisition unit is developed, the polarized probe can measure the real protection potential by eliminating IR drop and/or stray current interference, meanwhile portable surface data acquisition unit can automatically record protection potential. The on-site application of the system show that the system can quickly and accurately measure the protective potential of buried pipeline, reduce human measurement error, and really reflect the cathodic protection condition of pipeline.

Geogrid bridging over existing shallow flexible PVC buried pipe – Experimental study

2021 ◽  
Vol 113 ◽  
pp. 103945
Author(s):  
Emran Alotaibi ◽  
Maher Omar ◽  
Abdallah Shanableh ◽  
Waleed Zeiada ◽  
Mohammed Y. Fattah ◽  
...  
Keyword(s):  
Experimental Study ◽  
Buried Pipe

An Array of Multielectrodes for Locating, Visualizing, and Quantifying Stray Current Corrosion

CORROSION ◽  
10.5006/2828 ◽  
2018 ◽  
Vol 74 (10) ◽  
pp. 1093-1101 ◽  
Author(s):  
Ke Wang ◽  
Facundo Bob Varela ◽  
Mike Yongjun Tan
Keyword(s):  
Cathodic Protection ◽  
Laboratory Simulation ◽  
Buried Pipeline ◽  
Stray Current ◽  
Simulation Experiments ◽  
Corrosion Rates ◽  
Pipeline Corrosion ◽  
Probe Array

An array of multielectrode corrosion probes, designed based on a series of coupled wire beam electrodes (WBEs), has been devised as a new tool for locating, visualizing, and quantifying the effects of stray currents on buried pipeline corrosion. It has been demonstrated in laboratory simulation experiments that this WBE probe array is capable of detecting stray current corrosion affected sites along a pipeline, visualizing stray current corrosion patterns and corrosion rates, and evaluating the efficiency of cathodic protection against stray current corrosion. Based on these results, two applications of this WBE probe array have been proposed for stray current corrosion survey and monitoring.

Integrity Challenges Associated with Stray Current Corrosion Across Monolithic IJ's and Resolutions

2021 ◽  
Author(s):  
Ebrahim Salem Al Salemi ◽  
Saleh Salem Al Ameri ◽  
Ajiv Mohan Nair ◽  
Humaid Musabah Al Ali ◽  
Mario Jr Javier Zantua ◽  
...  
Keyword(s):  
Cathodic Protection ◽  
Ionic Current ◽  
Low Carbon Steel ◽  
Internal Surface ◽  
Low Carbon ◽  
Stray Current ◽  
Gas Industry ◽  
Factors Affecting ◽  
Steel Material ◽  
Internal Lining

Abstract Corrosion and subsequent failures is one of the main factors affecting uninterrupted operations of Oil & Gas Industries. Pipelines are considered as most convenient means of crude and gas transportation in Oil & Gas Industry. Buried pipelines generally made of low carbon steel material are protected externally by coating and applying impressed current cathodic protection (ICCP). Monitoring and maintaining adequate level of Cathodic Protection (CP) for such pipelines remains challenging for corrosion engineers due to increased level of field congestion, complexity in accurate current mapping and mitigation of corrosion phenomena. Failure of pipelines due to corrosion can be catastrophic with following consequences: Loss of containment fluid and thereby probable fatalityDamage to asset/company reputationSafety and Environment (Fire, Toxic gases and Oil Spill)Resource and downtime cost impact Isolation joints IJ's are designed with very high insulating material at mating areas and installed on pipelines by welding to avoid loss of Cathodic Protection (CP) current. Due to high electrical insulation, a potential difference is formed across of IJ's due to applied CP current and stray currents. In upstream Oil & Gas Industry, multiphase crude transported via pipeline will have certain percentage of water and will induce an internal conductive path across the IJs resulting in ionic current discharge at anodic areas within internal surface. This study focuses on factors contributing to such internal stray current corrosion, limitation in monitoring methodology and mitigation programs. The study concludes with recommendations such as design modifications, improvement in internal lining properties and improved installation guidelines. The study practically illustrates effectiveness of combined resistive bonding and zinc earthing cells installation for controlling stray current propagation in order to reduce the corrosion rate so as to maintain Integrity of pipelines.

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