![]() ![]() ![]() The Norwegian Petroleum Directorate (NPD) feared that the cessation of water injection after the incident could have a big impact on reservoir pressure and oil production from Draugen. ![]() The drawbacks of this approach were regarded as minimal. It was therefore thought safer to cover the damaged flowline with rocks and switch to one of the many other J-tubes on the platform. The latter would lose its barrier against the platform if the tube carrying the flowline to the NWIT was opened – risky since the gas riser tube was not designed to cope with full internal explosive pressure. None of these showed visible signs of damage.Ĭlearing up after the big rupture was a hazardous business, not least because the gas injection riser ran through a nearby J-tube. A lot of gravel and sandbags were displaced, and the flowline lay partly between other piping and control cables. The flowline had crumpled in a big heap only about 30 metres from the outlet. About 180 metres of internal piping had been driven out of the J-tube, while the end and 50-70 metres remained inside. A number of them are available to conduct piping to the seabed – known as pipe-in-pipe.Īfter further investigations using X-rays, it was determined that the break had occurred close to the end connection. Images showed that the flowline to the NWIT had fractured inside a J-tube leading out from the Draugen platform.Īs the name implies, such tubes have a sharp bend at the base which penetrates the platform wall. On this second occasion, however, the incident was assessed to have posed the risk of serious consequences.Īfter the rupture had occurred, a remotely operated vehicle (ROV) was sent down to document the extent of the damage. See the article on “1995 – first injection flowline failure”. The cause was the same as before – a manufacturing error which permitted high local pressure to cause a collapse. ![]()
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