British-Dutch energy giant Royal Dutch Shell on Wednesday said it had started production at the Corrib offshore gas field off the western coast of Ireland -- 20 years after discovering it.

The Corrib field is around 3,000 metres (9,800 feet) under the seabed, which is itself 350 metres below the surface and around 83 kilometres off Ireland.

The gas from the six wells in the field will be piped to the Bellanaboy terminal in northwest Ireland where it will be pumped into the network to Irish consumers.

Shell said in a statement that gas from Corrib could provide up to 60 percent of Irish gas needs.

"Today's announcement is a positive step for our gas portfolio. It is also good news for Ireland," said Andy Brown, Shell's Upstream International Director.

The field will initially produce around 45,000 barrels of oil equivalent per day.

Ireland imports most of its gas from the rest of Europe through a pipeline from Britain and will therefore be able to reduce its energy dependency.

Corrib was discovered in 1996 -- the first field found in Ireland since Kinsale Head in the early 1970s, which is still in use today.

Shell is the project operator and owns 45 percent of the project, with Norway's Statoil holding 36.5 percent and Canada's Vermilion 18.5 percent.

Shell said more than 1.1 billion euros ($1.2 billion) had been spent in Ireland for the project.