Monitoring Experiment of Electromagnetic Interference Effects Caused by Geomagnetic Storms on Buried Pipelines in China

Abstract

The electromagnetic interference effects on buried pipelines induced by geomagnetic field are monitored for the first time in China, including geomagnetically induced current (GIC) and pipe-to-soil potential (PSP). It is of great significance for studying the influence of geomagnetic storms on pipeline corrosion and protection in mid-low latitudes. In order to monitor the GIC and PSP simultaneously, a monitoring experimental scheme is proposed. The monitoring data are obtained at Changyi oil transportation station (36 • 30 N, 119 • 30 E) and Xiligu cathodic protection station (36 • 42 N, 119 • 12 E). For comparison, the geoelectric field data are acquired from the geomagnetic observatory near the monitoring stations. Based on the monitoring result and theoretical consideration, the effectiveness of potentiostat and the influence of GIC on the pipeline is evaluated by analyzing the correlation between the monitoring data and the geoelectric field data. The monitoring data show that the pipeline GIC maximum is 7.88 A caused by the magnetic storm commencing suddenly and the PSP positive offset of the two monitoring points exceeds the limit required by relevant standards. The GIC maximum is 3.98 A caused by the magnetic storm commencing gradually, and the PSP offset exceeds the standard when the potentiostat is cut off. The results of our research indicate that the geomagnetic storms can also cause serious corrosion of pipelines in the middle and low latitudes; the larger the distance between insulating flanges is, the stronger the corrosion situation of pipelines will be; the greater the variation rate of geomagnetic disturbance is, the more serious the corrosion of pipelines will be. Because the protection range of the cathodic protection station is limited and the response performance of the potentiostats is varied in different areas, medium or small geomagnetic storms can also cause serious corrosion even if the pipeline is protected by the potentiostat.

Observation Research on the Effect of UHVDC Grounding Current on Buried Pipelines

“…The analysis results show that the monitoring scheme in this paper is effective, and the monitor can also acquire the interference of geomagnetic disturbance on pipelines [18]. When the grounding current reached 6250 A, the maximum stray current of the Changyi site pipeline was 3.36 A.…”

“…The Changyi site is not only an oil transportation station but also a cathodic protection station. In order to achieve segment protection, two insulating flanges, whose resistance generally exceeds 10 MΩ [18], were installed at both sides of the Changyi site, dividing the whole pipeline into two segments. Two potentiostats were used to compensate the stray current in the pipeline outside the two insulating flanges separately.…”

Predictive Maintenance Framework for Cathodic Protection Systems Using Data Analytics

“…Stray currents can cause high-magnitude spikes (up or down) in the CP pipe potential [17,18]. Zebang et al suggest that geomagnetic storms can also induce fluctuation of the CP pipe potential on buried pipelines [19].…”

“…The CP pipe potential is measured between the pipe and a RE with a DC voltmeter. The RE is typically a CSE for underground pipelines, and the DC voltage reading is denoted as "V CSE " [19].…”

Research on Distribution Characteristics of DC Potential Near the UHVDC Grounding Electrode

“…The rated current of ± 800kV UHVDC can be as high as 6250A [1]. Under the monopole operating mode, the DC potential generated by the grounding current will have impacts on the power grid, oil and gas pipelines, railway circuit and other facilities around the grounding electrode [2][3][4][5][6][7]; Among them, the impact on the power grid will cause saturation of the transformers [3]. It is necessary to control the influence of grounding current on the power grid and pipeline for constructing the UHVDC projects [8].…”