ONGC plugs gas leak in Mumbai High

State-owned Oil and Natural Gas Corp (ONGC) today said it has plugged a gas leakage on an unmanned offshore installation in Mumbai High South oil and gas field, around 180-km off the Mumbai coast.

The gas leakage was observed in one of the unmanned wellhead platforms S1-6, the company said in a statement without saying when the leak was detected.

"A team of ONGC engineers with support from Indian Navy successfully plugged the gas leakage," it said.

Mumbai High is the ONGC's top oil and gas producing asset, lying in a water depth of 75 metres in the Arabian Sea.

The field, which started production in 1974, is divided into two -- Mumbai High North and Mumbai High South.

ONGC said after the leak was detected, the platform team immediately initiated all remote actions to shut down the well platform and to bleed off the pressure in the pipelines. Fire-fighting vessels were instantly deployed near the platform to provide water blanketing by continuously spraying water.

ONGC said its team could not land on the unmanned facility by helicopter or be transferred by a multi-support vessel due to bad weather conditions with high wind speeds of up to 35 knots, swell of 3.5 metres and strong surface currents in the sea.

"Having exhausted all available options to transfer ONGC team to S1-6 Platform, ONGC approached Indian Navy for help. After detailed discussions between ONGC and Indian Navy, it was decided to winch down ONGC team with the help of Indian Navy commandos," it said.

'Seaking' helicopter N555 of the Indian Navy reached ONGC process platform and took ONGC technical team to S1-6. "Braving rough weather, the team identified the leakage source successfully and safely plugged it within one hour making the well ready to flow. The entire operation was planned and executed with the utmost precision," the statement added.