Cathodic Protection Current Mapping In-Line Inspection Technology

Main Objective

The objective of this project is to develop a commercially viable in-line inspection tool that measures current traveling in the pipe due to cathodic protection or stray current from sources other than the pipeline system's cathodic protection system.
The data will provide information used to diagnose problems with the cathodic protection system, coatings and others. The tool should provide data in an easily understood format.

Public Abstract

A technique has been developed to continuously measure the magnitude and direction of cathodic protection current traveling in a buried or submerged pipeline, from inside the pipeline. From this information, important assessments about the condition of the external corrosion management system can be made, including: locations that may be susceptible to active corrosion, operational status of rectifiers, location of missing or damaged pipe coating, sites subject to cathodic interference and stray current corrosion, and location of unknown metallic contacts.
This technology is applicable for pipelines that are not internally coated and are capable of passing an in-line inspection tool but is specifically targeted to locations where aboveground current measurement or cathodic protection inspection techniques are impractical or impossible. This includes: High Consequence Areas, urban areas where the pipe is below pavement, shore approaches of offshore pipelines, swamps, water crossings and rough terrain where access is prohibitively expensive. In urban areas and crowded pipeline corridors, stray current is a common problem, but aboveground survey techniques are very difficult to perform and analyze. Over the past two years, this technology has advanced from the conceptual stage to development of a working laboratory prototype. Field development is in progress.