(Recasts lead, adds background)
ASTANA, April 28 Output at Kazakhstan's huge
Kashagan oilfield is not expected to restart this year after an
investigation revealed that long stretches of oil and gas
pipelines may need to be fully replaced, the project consortium
said on Monday.
The Central Asian nation of 17 million relies heavily on oil
exports, and the setback in development at its flagship field
could be a drag on state coffers.
Production at the offshore deposit, the world's biggest oil
find in 35 years, started in September but then halted in early
October after the discovery of gas leaks in the $50 billion
project's pipeline network.
"The current assessment, based on the results of an
investigation, is that both the oil and the gas pipelines might
have to be fully replaced," the consortium said.
The possibility that Kashagan's entire oil and gas pipeline
network could be replaced was raised by a Reuters article
earlier this month.
The field's oil is 4,200 metres (4,590 yards) below the
seabed at very high pressure, and the associated gas reaching
the surface is mixed with some of the highest concentrations of
toxic, metal-eating hydrogen sulphide (H2S) ever encountered.
The multinational group of oil companies developing Kashagan
has identified stress cracking due to sulphur-laden gases as
"the root cause of the pipeline issues" at Kashagan.
Much of Kashagan is built on artificial islands to avoid
damage from pack ice in the Caspian, which freezes for five
months a year in temperatures that drop below minus 30 Celsius
The North Caspian Operating Company (NCOC) consortium
includes Eni, Exxon Mobil, Royal Dutch Shell
, China's CNPC, Japan's Inpex and Kazakh
(Reporting by Raushan Nurshayeva; writing by Vladimir Soldatkin
and Oleg Vukmanovic; Editing by Alessandra Prentice and Jane