UK Energy Minister Charles Hendry introduced a well capping device today at the SPE Offshore Europe 2011 conference in Aberdeen that was built to seal off uncontrolled subsea wells and minimize environmental damage. The cap works by shutting in and holding pressure on an uncontrolled well and uses a choke and a series of valves that close down and stop the flow of hydrocarbons into the marine environment.
The device was constructed specifically for subsea wells on the UK Continental Shelf (UKCS). It features a modular design so it can be attached to various points of subsea equipment.
The cap is rated for deployment in water depths up to 10,000 ft on wells flowing up to 75,000 bbl/day at 15,000 psi. Its portable size and weight also makes it relatively easy to deploy quickly from a wide range of vessels.
The capping device was designed and manufactured over a period of seven months, made possible through access to pre-existing equipment systems, a streamlined project management approach and close collaboration with the industry’s global supply chain.
The device has completed stringent factory acceptance and system integration testing and will be handed over to Oil Spill Response Ltd, which will store it in readiness at an operational base in the northeast of Scotland with the appropriate deployment capabilities.
James House, chairman of Oil & Gas UK’s Oil Spill Prevention and Response Advisory Group (OSPRAG) and regional VP and managing director of Apache North Sea, said, “The successful completion and availability of this cap marks a significant step forward in industry preparedness and significantly bolsters our capability to deal with a major loss of well control. Despite the fact that there has not been a major loss of well control in the UK in over 20 years of offshore operations, we believe that having such a contingency device here in the UK is essential, as it allows a quick response no matter how unlikely a scenario this is.”
He continued, “Our long-term focus remains, however, to prevent such incidents from occurring in the first place, and the cap complements other work being carried out by OSPRAG in spill prevention. OSPRAG’s work demonstrates the industry’s determination to learn from experience and continuously improve the safety of operations so that risks to people and the environment are minimized or eliminated.”
The decision to construct the cap came as a result of a recommendation by OSPRAG, a group set up by the industry, regulators and trade organizations following Macondo.
The vast majority of UKCS operators participated in the development of the device following focused discussion and collaboration.
The design development was overseen by OSPRAG’s Technical Review Group, working with BP, which agreed to manage the detailed design, procurement and construction phases, with support from engineering services firm Wood Group Kenny. The device was commissioned by Oil Spill Response Ltd and built by Cameron in Leeds.
To view an animation showing how the cap works and how it can be deployed, click here.
Capping device key facts
It can be deployed:
• At the widest possible range of wells and oil spill scenarios that could occur on the UKCS, including West of Shetland;
• To various points of the subsea stack;
• At water depths between 100 meters and 3,048 meters (328 ft to 10,000 ft);
• In wave heights of up to 5 meters (16 ft) depending on the vessel/rig used;
• From a variety of multiservice vessels or drilling rigs;
• To wells flowing up to 15,000 psi and 121°C (250°F);
• Even where there is a high content of hydrogen sulfide present;
• On to a well flowing up to 75,000 bbl/day.
• Length – 4.26 meters.
• Width – 3.97 meters.
• Height – 7.14 meters (can be adjusted for transportation).
• Footprint – 15.8 sq meters if frame fully plated.
• Weight – approximately 40 tonnes.