Fifty miles off the Mayo coast, the Sedco 711 rig has drilled what may be the last well before production on the Corrib North gas field.
However, further drilling will take place in the Corrib area, to the north and south on the Slyne Basin, Mr Briain O Cathain, managing director of Enterprise Energy Ireland (EEI), told The Irish Times on the rig late last week. As the main indigenous source of Ireland's future energy needs, Corrib is described as "two-thirds" the size of Kinsale Head but may prove to be much larger than that, following further exploration.
It will be at least two years before the first gas - almost pure methane - is piped ashore from the field - in about 1,000 feet of water - to the shore at Rossport. The gas reservoir containing the hydrocarbons in sandstone material is another 3,500 metres (10,500 feet) below the seabed.
By then, Sedco 711 will have moved on, to be replaced by sub-sea technology.
Mr Ciaran Nolan, geophysicist with EEI, described how the five wells drilled on the field would look if superimposed on a map of Dublin. They would extend from Croke Park to St Stephen's Green, King's Inns, Temple Bar and Dolphin's Barn. "In 2003, we hook these up to a manifold and run the pipeline ashore."
Remotely operated vehicles have replaced divers as the main instruments for this highly technical operation, in water three times the depth of the Kinsale field. Technology has revolutionised the work on the semi-submersible drilling rig, which has roamed the world's exploration fields from the North Sea to west Africa. It currently costs about £110,000 sterling a day to run, including helicopter transport costs of crews to and from Carrickfin airport, Co Donegal.
Last week, during a press trip to the location, by helicopter from Knock airport, most of its 90 workers, many with Scottish accents and connections ranging from Aberdeen to Amsterdam, were taking a break from drilling, while intensive logging of material was being undertaken by Schlumberger geologists contracted to EEI.
The information is sensitive (mobile phones are not permitted on the rig) but is immediately available on a restricted access website to the Government's petroleum affairs division in Dublin.
Mr O Cathain stressed that it was "nonsense" to suggest that the information was tampered with in any way. "Our partners, Statoil and Marathon, and the PAD, receive this the same time as us."
For the next few months, the main focus of EEI's energy will be on land. The company recently resubmitted its planning application for the terminal at Bellnaboy Bridge, inshore from the landfall at Rossport - a sandy approach which proved to be the most suitable after extensive surveys stretching from north Clare to Sligo.
The company is still confident that the target of autumn 2003 will be met. This may extend to winter 2003 if there is an appeal to An Bord Pleanala. The route for the pipeline down Sruwaddacon Bay, at the corner of Broadhaven Bay, is a highly sensitive area environmentally .
Ireland's gas market is relatively small, but growing, and market considerations will dictate the pace of Corrib's development - and whether more wells will be drilled after production. Currently, Kinsale is the sole source of indigenous gas, but is declining. Last February, the Government sanctioned construction by Bord Gais of a second gas interconnector parallel to its existing link with Scotland.
Bord Gais is to construct a pipeline from north Mayo to Craughwell, Co Galway, connecting the Corrib field with the national grid extending to Dublin and Cork. That pipeline will run past Bellacorick power station which, Mr O Cathain believes, will be developed for further production beyond its current life. "Bord Gais talks about bringing gas to the west," he says. "But the gas will be coming from the west, not the other way."
