The electric field signature method is a non-intrusive technology for monitoring internal corrosion, erosion and cracking in pipelines, process piping and vessels. The method is based on feeding an electric current through the monitored object, and measure internal metal loss from changes in the electric field over time, measured between electrodes installed at the objects external wall.
Since the first field installation (1991), this system has been installed for a wide range of applications on under ground and above ground pipelines, on subsea pipelines and facilities, process piping and vessels, and it is also used in laboratories for materials and corrosion research. The electric field signature method may be installed on new installations, but may also be installed on existing objects, such as underground pipelines where corrosion has already been identified.
This paper provides a brief presentation of the electric field signature method and typical applications of the technology, seen in the perspective of pipeline corrosion management. A method for finding optimum locations for corrosion monitoring on pipelines is also discussed, and typical field data have been presented.
Although oil and gas transport through pipelines and flow-lines is almost as old as the oil industry itself, new technology may provide significant improvements with respect to the pipeline corrosion management strategy. The pipeline management philosophy presented in this paper is based on active use of corrosion predictions, corrosion monitoring and inspection in order to optimise the operation of a pipeline.