Interview by Rikki Stancich
As the only UKAS (United Kingdom Accreditation Service) approved hyperbaric test laboratory, the National Hyperbaric Centre is playing an increasing role in testing new equipment for offshore oil and gas decommissioning.
Formerly a government-backed entity, the now-independent company provides expertise and services to the subsea industry and pressure-related industries, offering a range of services from commercial diver training, hyperbaric welding and subsea testing and consulting.
The NHC has deepwater simulation facilities capable of both manned and unmanned testing. A variety of hyperbaric pressure test vessels can be utilised to create depths of up to 8000m/26,300ft, and due to increasing demand, the centre is due to expand its facility in the near term. Its unique team brings together extensive, cumulated experience of working in pressurised environments, across a broad range of subsea activities.
DecomWorld speaks to testing manager, David Cruikshank, to learn more about how operators can take advantage of the National Hyperbaric Centre’s (NHC) facilities, and the type of innovative decommissioning R&D it has been involved with over the last twelve months.
DecomWorld: What innovations in decommissioning equipment and techniques has the National Hyperbaric Centre been working on?
David Cruikshank: We have so far only been involved in Shell’s Brent Delta project, which is currently looking at what to do with the gravity base structure (GBS) storage cell contents.
Shell was testing the underwater diving methods and how the divers will drill onto the concrete cells to take samples of the fluids. Currently it is unknown as to whether the contents are radioactive or toxic, so it is a contamination containment issue.
Shell has been testing new equipment to drill into the top of the tanks in order to install a mini wellhead through which to run a sampling tool.
DecomWorld: What is new about the technology being tested?
David Cruikshank: They have employed standard technology (hot tap) but are deploying it on a smaller scale. Because it has been scaled down, this new equipment needs to be tried out and tested. We can replicate the underwater conditions and pressures to effectively test the equipment.
DecomWorld: Were the tests successful?
David Cruikshank: It is an on-going project – there are more tests and trials to be carried out, and the technology is scheduled to be taken offshore early to mid-next year.
DecomWorld: How is the facility geared to assist operators drive down decommissioning costs?
David Cruikshank: We are a test facility, so we help operators to to test new equipment at given water depths. Our job is to help operators make sure that everything works. By testing equipment in a controlled environment where offshore subsea conditions are simulated, we provide operators with a form of insurance – they spend a few £10,000 to save a few £ million.
DecomWorld: How is the National Hyperbaric Centre positioned to take advantage with increasing demand in coming years?
David Cruikshank: We are already fairly stretched and are looking at adding additional hyperbaric chambers. These are fairly large test chambers; the indoor chamber are 3m x 8m and can hold 63,000 litres of water and can test divers in a wet or dry atmosphere. The tanks can simulate depths and associated press of up to 3,500 metres. The outdoor tank is 12m x 9m and can hold 975,000 litres of water.
DecomWorld: How much of your turnover is represented by decommissioning today, and by how much is it likely to increase in the next 12 months?
David Cruikshank: Currently decommissioning tests account for around 15% of the turnover. This will likely increase to 25% in the next year.
To respond to this article, please write to the Editor: Rikki Stancich