It may cost as much as 15 times more to rebuild the pipelines needed to restart operations at the giant Kashagan field in the Caspian Sea, a metallurgist said.

Kashagan is one of the largest oil fields in the world, with an estimated 16 billion barrels of oil reserves. Production was halted in October, less than a month after it started, when a pipeline associated with the field cracked open.

A source close to the project told online energy news website Quartz corrosive hydrogen sulfide found within the natural gas associated with the field causes the field's pipelines to crack open almost as soon the hydrogen sulfide is exposed to moisture.

Barry Hindin, a corrosion engineer at Battelle Memorial Institute, told the news site a nickel-based steel alloy that would resist hydrogen sulfide may cost the consortium operating Kashagan as much as 15 times more than conventional pipelines.

In February, the U.S. Energy Information Administration said it expected Kashagan to return to service in 2015, but below its initial production target of 370,000 barrels per day "because technical challenges and high development costs may limit its expansion."

There was no statement on the potential restart from the North Caspian Operating Co., the consortium developing the field.

[Quartz]