Offshore staff
LONDON – Britain’s Department of Energy and Climate Change has issued a statement on the gas leak from the Elgin field in the central North Sea.
Total believes the leaking hydrocarbons are entering the well from a rock formation above the producing reservoir of the Elgin field. This makes the volume of gas ingress difficult to estimate.
The company assumes that afailure of the well system caused gas to enter another part of the well not normally designed to handle gas. It estimates entry at a point 4,000 m (13,123 ft) below the seabed, and this is allowing gas to travel contained within the well system to the platform.
However, thereis no evidence that gas is being released below sea level.
To tackle the release, Total is considering two options:
- Drill a relief well – the company is mobilizing two drill rigs to drill a well to intersect the main well and then shut off the flow of gas
- Block the well by pumping in heavy mud to suppress the flow of gas.
DECC has convened a government regulators’ group meeting to ensure the government’s response “is coherent and joined up.” The group will now meet on a regular basis to consider Total’s actions and the government’s response to the incident.
To date, DECC says the response from Total and government agencies has been very effective.
Total has confirmed to the government’s inspectors that the platform’s flare remains lit, although latest aerial surveillance suggests the flame may be reducing in size. The flare is located in a position where the prevailing wind blows the gas release away from it – for the time being, weather conditions remain favorable.
However, the company is considering options for extinguishing the flare if it does not go out by its own accord. These include using a helicopter to drop water or other material to extinguish the flame; use of fire fighting vessels, if their fire monitors are capable of reaching the height of the flare; or extinguishing the flare by purging with nitrogen, depending on safe access to the platform.
Aerial surveillance continues three times a day, with two platform supply and four anchor handling tug and supply vessels on hand, and a Hercules airplane is on standby if dispersants are needed.
Other intervention vessels due to arrive on site shortly are Allseas’ Highland Fortress ROV support vesselBig Orange; the Kommander Stuart MSV and the Island Intervention MSV.
The latest indication is that thesheen on the nearby sea surface has spread to an area of 22 x 4.5 km (13.7 x 2.8 mi) and the maximum volume of gas condensate in the water is 3.8 metric tons (4.2 tons). DECC’s view is that there is no substantial risk to the environment.
Total has also drafted in international well control experts using worldwide support contracts who are working with Total’s teams on site in Aberdeen.
3/30/2012
