Start-up of the much-delayed field had been postponed to the second half of this year, from the previous first-quarter date, as the operator’s parent Gazprom had signalled that it would not kick off production until it gained tax concessions.

Launch of the project had already been hit by cost overruns and delays to construction of the $2 billion Prirazlomnaya platform, which has been lying idle with its crew onboard at the icy field location since December after tow-out last year from the state-owned Sevmash fabrication yard.

However,