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ASTANA, April 28 (Reuters) - Output at Kazakhstan's hugeKashagan oilfield is not expected to restart this year after aninvestigation revealed that long stretches of oil and gaspipelines may need to be fully replaced, the project consortiumsaid on Monday.
The Central Asian nation of 17 million relies heavily on oilexports, and the setback in development at its flagship fieldcould be a drag on state coffers.
Production at the offshore deposit, the world's biggest oilfind in 35 years, started in September but then halted in earlyOctober after the discovery of gas leaks in the $50 billionproject's pipeline network.
"The current assessment, based on the results of aninvestigation, is that both the oil and the gas pipelines mighthave to be fully replaced," the consortium said.
The possibility that Kashagan's entire oil and gas pipelinenetwork could be replaced was raised by a Reuters articleearlier this month.
The field's oil is 4,200 metres (4,590 yards) below theseabed at very high pressure, and the associated gas reachingthe surface is mixed with some of the highest concentrations oftoxic, metal-eating hydrogen sulphide (H2S) ever encountered.
The multinational group of oil companies developing Kashaganhas 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 avoiddamage from pack ice in the Caspian, which freezes for fivemonths a year in temperatures that drop below minus 30 Celsius(-22F).
The North Caspian Operating Company (NCOC) consortiumincludes Eni, Exxon Mobil, Royal Dutch Shell, China's CNPC, Japan's Inpex and Kazakhstate-run KazMunaiGas. (Reporting by Raushan Nurshayeva; writing by Vladimir Soldatkinand Oleg Vukmanovic; Editing by Alessandra Prentice and JaneBaird)
