Sunday, April 1, 2012

Leaking Gas Rig Now Less of a Threat to Shipping

Shipping Exclusion Zone Imposed but Explosion Risk Reduced
Shipping News Feature

NORTH SEA – Gas continues to leak from the TOTAL gas rig and a two mile exclusion zone has been imposed to protect shipping in the area. Misinformation given to the press that the flare atop the rig could safely be extinguished remotely became redundant today as the flame extinguished itself naturally. The major risk had always been that a change in wind direction would cause the leaking gas to blow onto the flame and cause an explosion. Energy Minister Charles Hendry said:

“TOTAL confirmed to me this morning that the flare on the Elgin platform has naturally extinguished itself. This comes as very welcome news and a considerable relief. Although the platform was designed to use the prevailing wind to keep the flare from the escaping gas, the fact the flare is out removes a major risk from the equation.

“The task now is very clear – every effort must be made to locate and stop the gas leak. Following my visit to TOTAL’s emergency control room yesterday, I know they have some of the best expertise in the world on hand to consider their options. The Government continues to monitor the situation very closely to ensure this incident can be resolved as quickly and with as little risk to human life and the environment as possible.”

The reduction in risk means that TOTAL engineers can get on with solving the problem which it is believed stems from gas being released from the well system to the environment at the platform deck level, and therefore above water. This means it is likely a failure of the well system has allowed gas to enter another part of the well not normally designed to handle it.

The point of entry has been estimated at a point 4,000m below the seabed and this is allowing gas to travel contained within the well system to the platform. There is no evidence that gas is being released below sea level.

There are now two possible options to tackle the gas release: drilling a relief well – TOTAL are mobilising two drill rigs to drill a well to intersect the main well and then shut off the flow of gas or blocking the well with "heavy mud" – using a mixture containing mineral compounds to be pumped into the well to suppress the flow of gas. This second method would certainly provide a swifter solution – presuming that it works.

The incident has caused a rethink about the way such occurrences should be dealt with, had the wind changed when the rig was fully manned a disaster to echo that of Piper Alpha, a gas rig which exploded in 1988 killing 167 people might have been the result. A plan to deal with incidents in the Elgin field was published by the Department of Energy and Climate Change (DECC) in January and this has now been amended to ensure immediate publication of any incident details. Updates from TOTAL can be seen HERE.