British utility Centrica said it will spend 60 million pounds (US $77 million) to unlock an extra 3 billion cubic feet (Bcf) of natural gas reserves from fields under the East Irish Sea.

The project will simplify the process to bring gas from offshore to the North Morecambe terminal and start later this month, Centrica said on Wednesday.

The project will last for nine months with the rig campaign completed in February 2018, a company spokesman said.

Morecambe Bay production is currently around 212 million cubic feet a day, so the addition to daily production will be quite marginal as the 3 Bcf will be produced over a long period of time, he added.

“With nearly 300 billion cubic feet of gas still in place under the East Irish Sea, major projects like this will help ensure we maximize the potential of these fields and continue supplying gas for U.K. homes and businesses,” said Tamsin Lishman, Morecambe Bay director for Centrica’s E&P business.

The news comes amid concerns about tight gas supplies in the cold season next year due to an ongoing outage at Centrica's ageing Rough gas storage site.

Britain’s largest natural gas storage site, Rough, will not be available for gas injection until the end of next April, due to issues with its wells.

Britain depends on stored gas reserves to help manage winter demand spikes and to ensure security of supply. Rough is the largest storage site in the country but is more than 30 years old and repeated outages have shown its vulnerability.