Pipeline inspection method for non-piggable pipelines

Many pipeline operators are currently facing the consequences of an aging grid, making pipeline inspection increasingly important. Large parts of pipe networks can be inspected using in-line inspection (ILI) tools, also known as intelligent pigs. For pipelines that cannot be inspected internally, alternative techniques, such as external corrosion direct assessment (ECDA), can determine pipeline condition.

Project
Currently used above-ground surveying techniques are not as reliable as ILI tools in finding corrosion defects. Consequently, KEMA developed a probabilistic approach that considers the uncertainties involved in the ECDA process. This project’s goal was to improve two commonly used survey techniques, DCVG and CIPS, to gain better data quality. By using the newly developed ILI survey equipment, researchers hoped to demonstrate more accurate predictions of the location and the severity of identified defects, which would result in fewer excavations and cost savings.

Objectives
The project’s objective was to create a new generation of survey equipment that would improve the detection of coating defects and corrosion anomalies on pipelines. Using the new equipment would mean that fewer excavations were needed for verification purposes, thereby saving time and reducing costs for the customer.

Benefits
> Higher quality of data. Unreliable data can be identified more easily
> Data can be imported into the direct assessment module of an existing pipeline integrity management system (PIMS)
> Integration of DCVG, CIPS and dGPS technology in one piece of equipment
> Reduced number of excavations needed for verification purposes; improved technology results in time savings and cost reductions
> CSS uses known methods for inspections, combined with the latest insights. This makes comparison of new and old data possible
> The CSS can inspect pipelines under AC-interference conditions > Continuous feedback for surveyors (graph on computer screen)
> Potential for wireless inspection (under construction) KEMA developed, tested, and validated the new CCS+ equipment. Eventually, we will rent the equipment and provide pipeline inspection services.

Project coordinator
> KEMA, the Netherlands

Project partner
> Gasunie, the Netherlands

Project details
> Duration: 2008 – 2010