Elizabeth Nicholson, Corrosion 2015, Paper 5675
Describes a fuzzy logic model intended for quantitative risk analysis to the integrity of buried pipelines. The proposed approach correlates data from combined CIPS+DCVG coating surveys to the soil resistivity, in order to define an indicator that expresses the corrosion susceptibility at a given coating defect location. Inputs used in the mathematical model include: DCVG defect severity, CIPS pipe-to-soil “OFF” potentials and local soil electrical resistivity
Elizabeth Nicholson, Corcon 2014 Corrosion Conference & Expo, Mumbai
Many types of surveys are done to allow the operator to assess the condition of a pipeline. Two surveys are essential to any pipeline integrity management program, coating integrity and cathodic polarization. Coating integrity is investigated by generating a pulse on the pipeline, then walking the pipe to locate any voltage gradients in the soil.
Elizabeth Nicholson, B.Eng.,Presented at: POLSKI KOMITET ELEKTROCHEMICZNEJ OCHRONY PRZED KOROZJĄ STOWARZYSZENIA ELEKTRYKÓW POLSKICH w WARSZAWIE September 19-21, 2012 in Jurata, Poland
Coatings prevent corrosion by creating a barrier between the structure and the electrolyte. Cathodic protection works by changing the potential of the structure to interfere with the corrosion process. Both work together to protect the structure. Surveys can be done to evaluate the condition of the coating and of the cathodic protection.
Combined Close Interval Potential Surveys and Direct Current Voltage Surveys for Increased Pipeline Integrity
John Peter Nicholson, Eurocorr 2010
With today’s electronic instrumentation, it is possible to combine close interval potential surveys (CIPS) with direct current voltage gradient surveys (DCVG) of buried and underwater pipelines for improved accuracy in assessing the level of cathodic protection combined with locating coating defects without spatial errors.
Elizabeth Nicholson, B. Eng, Poland 2010
Stray currents can impact the ability to protect a pipeline or other buried metallic structure from corrosion. They can be generated from a variety of manmade and natural sources. Common sources of stray currents are cathodic protection on other lines, DC transit systems and telluric activity.
Peter Nicholson,NACE Corrosion 2008 Conference & Expo , Paper No. 08123
Traditionally, close interval potential surveys (CIPS) and direct current voltage gradient surveys (DCVG) have been undertaken separately and the corrosion engineer has been saddled with the task of trying to correlate the results of these surveys, to assess the level of cathodic protection on the pipeline and the effect of coating holidays on the effectiveness of the cathodic protection system.