Norwegian gas wouldn’t reach Europe without pipelines, so it is reassuring to know that health checks of these 20 or so arteries have yielded positive results. Orbit+ Pipeline is DNV Software’s new generation software for Pipeline Integrity Management, designed in close cooperation with DNV Energy.
Covering both offshore and onshore pipelines, it is a fully multi-user and web-enabled system for pipeline data management, risk assessment, inspection management and aggregated management reporting.
“We’re pleased to say that the overall findings of last year’s inspection programmes confirm that our pipelines are in good technical condition,” reports Per Atle Strømme, vice president for the transport network at Gassco. As operator, the company is responsible for about 8,000 kilometres of pipelines with an estimated value of NOK 160 billion if the system had to be restored today.
Like the Norwegian Police Security Service (PST), Mr Strømme uses the concept of ‘threat pictures’ when explaining condition management of the pipelines.
“We use a risk-based methodology to understand which threat pictures we could face,” he explains. “That might be corrosion, for instance; trawl damage, or collisions with anchors of the kind which damaged the Kvitebjørn-Kollsnes gas line.”
Programmes for both external and internal inspection have been established. Remotely operated vehicles (ROVs) are used to inspect underwater pipelines. Such work includes identifying free spans which are longer than the acceptance criteria.
Internal checks are conducted with the aid of pigs – instrument packages which detect corrosion and measure wall thickness. On land, cathodic protection and third-party activities such as excavation are among the targets for inspection work.
“It’s also very important to monitor what goes into the pipelines, and control room staff play an important role in that context,” says Mr Strømme. “Good control of hydrogen sulphide and dew point for water means that we don’t need to carry out internal inspection as often as before.”
All information from the inspections is collected and summarised in the Orbit+ Pipeline computer tool, which also includes historical and design data for the various pipelines.
“Together with suppliers and research institutes, the industry has constantly improved its methods for design and condition management of pipelines,” observes Mr Strømme. “I don’t know of anyone else worldwide who is better equipped to identify and reduce threat pictures for the technical integrity of this type of pipeline.”
By Gassco
Date: 2009-11-01
