* Relief well may need to be drilled to lessen leak -union
* Gas cloud visible 7 miles away -eyewitnesses
* Outer layers of pipe casing structurally compromised
By Oleg Vukmanovic
LONDON, March 26 A gas cloud has encircled
Total's Elgin Franklin platform in the North Sea after
failed attempts to shut a problematic production well caused a
leak, an RMT union official said, based on eyewitness accounts
from workers on nearby rigs.
"People seven miles away can see a gas cloud coming from the
Total rig," said Jake Molloy, the head of the section of the UK
union that represents offshore oil and gas workers.
A separate relief well may need to be drilled to ease
pressure and allow emergency teams to regain entry to the rig
and try to fix the problem, he said, citing engineers.
"The well in question had caused Total some problems for
some considerable time ... a decision was taken weeks ago to try
to kill the well, but then an incident began to develop over the
weekend," he said.
"Engineers have told me that it is almost certain that gas
is leaking directly from the reservoir through the pipe casing,"
He said the only way Total can stem the leak is to drill a
relief well to ease reservoir pressure.
"If gas is leaking directly from well casing below the mud
line, the best recovery option will probably be to drill a
relief well to intersect the problem at a point well below the
leak. The relief well can then be used to kill the well," an
engineer familiar with the matter said.
"This option is likely to take several months and cost a lot
of money. In the meantime a lot of gas may potentially get
released into the atmosphere," he added.
A shallow water-depth of 93 metres at Total's production
site should make it easier to drill a relief well, compared with
BP's difficulties after the 2010 Macondo oil spill in the Gulf
of Mexico, which was about 1,500 metres deep.
Total, which declined to comment immediately on the cause of
the leak and the need for a relief well, has not been able to
stem the leak, which started on Sunday and led to the evacuation
of all 238 platform personnel.
"Production has stopped," Total UK said earlier.
Molloy said the outer layers of the pipe casing have been
structurally compromised, channeling gas to the surface directly
from the reservoir.
"The engineer I have spoken with says that he has no idea
how to go about fixing this type of problem," he said.
NOT ABLE TO SAY WHEN
Total was unable to predict when production from the
platform would resume, which a spokesman said would probably not
"The gas leak at the Elgin Well Head Platform remains
ongoing, and we are taking all possible measures to try to
identify the source and cause of the leak and to bring it under
control," Total UK said in a statement.
An aerial surveillance flight confirmed there was a sheen on
the water, which was detected near the platform, and an aircraft
carrying dispersant was on standby at East Midlands airport.
The appearance of a sheen, thought to be gas condensate, is
a direct consequence of the gas leak and usually evaporates
naturally, a Total UK spokeswoman said. Gas condensates are a
mixture of light hydrocarbon liquids.
The British energy ministry said the environmental impact of
gas condensate leaks is substantially lower than from oil
The peak production capability for the Elgin/Franklin field
is 280,000 barrels of oil equivalent per day, which includes
175,000 barrels of condensate and 15.5 million cubic metres of
gas (mcm/d), according to Total.
On Monday morning, 150 non-essential personnel had been
evacuated to Aberdeen and a further 69 employees had been
brought to neighboring offshore installations.
Oil produced at the facility is exported via the BP-operated
Forties Pipeline System to Kinneil in Scotland, and its
gas flows through the SEAL pipeline to Bacton in Norfolk.
Gas flow through the Bacton SEAL terminal fell by around 10
mcm/d to 7 mcm/d early on Monday, data provided by UK energy
network operator National Grid showed.
UK gas prices for day-ahead delivery surged by almost 9
percent following news of the supply cut from Elgin to 57.70
pence per therm.