New technology revolutionises gas pipeline checks
Oslo: Gassco has joined with Det Norske Veritas (DNV) to develop a new acoustic inspection method which allows the internal and external status of gas pipelines to be accurately characterised.
Picture: Pipeline inspection at Kalstø
Measurements can also be made without reducing the gas flow, and the net effect is a big improvement in the safety of gas pipelines plus substantially reduced inspection costs.
This solves a long-standing problem for the oil and gas industry, which has previously had to reduce gas flows to check pipelines for possible maintenance requirements. Not only has that imposed considerable expense, but existing inspection methods have also been insufficiently reliable.
The world market for gas pipeline inspection is estimated to be in the order of USD 300 million per year, and the new method can be used both on land and offshore. Building on acoustic resonance principles, it is based on part on solutions and technology employed in the Second World War.
DNV applied the same principle to develop a method for determining whether the tanks in the German battleship Blücher sunk off Drøbak on the Oslo Fjord contained water or oil.
Pigs are devices normally used not only to clean but also to carry out condition monitoring in pipelines. Attaching a simple “necklace” to a standard cleaning pig will now make it possible to determine condition through absolute measurements of the whole pipeline surface – a radical improvement.
Gassco has already tested the new technology on one of its gas pipelines and found the results highly interesting. Performance has been so good that Gassco and DNV have decided to establish a joint venture to commercialise the solution. The big oil companies have also begun to show an interest.
“For us, this means that inspection and maintenance costs can be sharply reduced while enhancing the quality of checks,” says Brian Bjordal, president and CEO of Gassco. “Inspecting with acoustics provides a clear improvement because wall thickness can be measured much more exactly. This technological advance probably has a global user potential.”
“Gas pipeline inspection is revolutionised with the new solution,” concurs Henrik O Madsen, chief executive of DNV. “Based on acoustic half-wave resonance, it represents a technological quantum leap. The industry will now secure effective decision support for maintenance and repair, and we will enhance safety and cost-efficiency for the pipeline network.” (29.5.2009)