According to partner Vermilion Energy, production is expected to reach a peak of 58 MMcf/d within six months.
Corrib was discovered in 1996, 83 km (51.6 mi) from the northwest Mayo coast. It contains an estimated 1 tcf of gas.
Shell has developed the field with six production wells in water depths of around 350 m (1,148 ft) and an umbilical providing electrical and hydraulic power for the subsea controls.
Gas will head through a 20-in. pipeline, laid by Allseas’ Solitaire in 2009, to the Bellanaboy Bridge gas terminal in Mayo for processing and subsequent transfer to the Bord Gáis Eireann pipeline network.
The 8.3-km (5.2-mi) onshore section of pipeline from the reception point in Glengad to the terminal also includes a 4.9-km (3-mi) section under Sruwaddacon Bay.
During the operation phase, the subsea facilities will be monitored and controlled 24 hours a day from the control room in the onshore gas terminal.
At peak Corrib could supply up to 60% of Ireland’s gas needs.
The project’s progress has been delayed repeatedly by environmental concerns, notably the impact on the peat bogs along the onshore route.