OSPRAG, the UK’s Oil Spill Prevention and Response Advisory Group, has agreed to move ahead to commissioning detailed designs for a full/partial pressure capping device which has the potential to become a key element of the UK offshore oil and gas industry’s oil spill response contingency plans.
OSPRAG was set up in May to learn from the Macondo incident in the Gulf of Mexico and ensure that the UK oil and gas industry’s offshore practices and procedures continue to be robust and fit for purpose. In July it asked engineering services company Wood Group Kenny to develop and evaluate possible well containment and capping solutions for UK offshore use. Of the three design concepts put forward, OSPRAG has opted to progress with a modular device which could effectively close off or ‘cap’ a well in the event of a blowout, preventing oil from leaking into the environment. The recommended design is considered to be the most appropriate solution given the weather conditions typically found in the UK, and specifically to the west of Shetland.
Mark McAllister, chairman of OSPRAG and chief executive of Fairfield Energy Ltd, said: “This represents another important step towards strengthening the UK’s oil spill response capability in the light of what we have learned from events in the Gulf of Mexico this summer. We have already improved the UK’s capacity to capture oil leaking from an uncontrolled well with the arrival earlier this month of two containment devices from the Gulf of Mexico. These were developed by BP in response to the Macondo incident and are now based in Southampton with OSRL, the industry’s shared oil spill response organisation.
“The development of the capping device is the next phase. The design allows installation at various points of the subsea well head, the blow-out preventer (BOP) or lower marine riser (LMRP) assembly to stop the flow of oil and buy valuable time for engineers to develop a permanent solution for killing the well.
“This work can also help inform the development of a longer-term regional or global (non-US) response which is being co-ordinated by the Global Industry Response Group under OGP (the International Association of Oil & Gas Producers),” he added.
Brian Kinkead of Oil & Gas UK, who leads the OSPRAG technical review group responsible for developing the capping concepts, said: “Time is of the essence for minimising environmental impacts when bringing a well under control. Met-ocean constraints can become a concern, particularly west of Shetland where wind and sea conditions can be severe. The cap design therefore needs to be compact, relatively low weight and flexible for ease of handling and installation in short operational weather windows.”
The approach is likely to utilise a variety of adapters, connectors, a main body incorporating two gate valves, choke and kill manifolds and a variable flow ported sub/cap with an overall system rating for 15,000psi working pressure. Such a device could be deployed in sea states of up to 5 metres, depending on the vessel used, and capping could be achieved within 20 – 30 days of the incident, depending on weather and well site conditions.
The detailed design and procurement phase will be project-led by BP, working closely with the OSPRAG technical review group and other UK operators. Estimated manufacturing time is currently 11 months but there is a possibility of shortening this once the final equipment configuration is agreed and priorities are set.
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Source:Oil&gasUK, October 18, 2010;