In the past couple of years flotillas of Irish exploration minnows seeking their fortunes have sailed out to the high seas in search of fortunes, egged on by soaring commodity prices and a legacy of lack of investment that has left many majors scrapping over prospects they would have ignored a decade ago.

Last week Providence Resources announced a new partner for what it hopes will be a project that is going to yield significantly more than just scraps. ExxonMobil will initiate development and exploration work on a prospect in the Porcupine Basin off the west coast of Ireland. Providence and partner Sosina have farmed out an 80% interest in the Dunquin prospect to the US giant, with Providence retaining 16% and Sosina 4%.

The stakes are high. Providence and its experts reckon that seismic survey work already carried out on the Spanish Point prospect, north of Dunquin, suggests that there could be as much as 1.85trn cubic feet of gas and up to 280m barrels of oil waiting to be exploited, while the Dunquin prospect itself could contain 25trn cubic feet of gas and four billion barrels of oil, making it the biggest potential fields in western Europe.

To put that in some perspective, the troubled Corrib field being primarily developed by Shell, contains an estimated 1trn cubic feet of gas.

Industry experts estimate that ExxonMobil is likely to spend more than $100m on initial development, drilling and exploratory work. The large investment is largely down to the fact that the prospect is located in very deep water, where drilling costs are significantly higher than in regions such as the Celtic Sea.

Chief executive of Providence Resources, Tony O'Reilly Jnr, declined last week to put a figure on the cost of the work, but claimed that it is not a case of whether oil and gas can be extracted, but how much.

"The proof will be in the pudding, " he concedes, "but it's a question of patience and sticking with it. But this is a proven discovery and has already flowed hydrocarbons.

There's a huge intersection of hydrocarbon bearing sand there. We've got a firm of third party consultants doing evaluation work on the Spanish Point reservoir. We've already got notional development scenarios worked out. Now it's a question of how many wells are we going to need to take out whatever we determine are the final reserves that are in place there."

Getting ExxonMobil on board at the Dunquin prospect brings another major into the Irish exploration sector. O'Reilly pointed out that the company rarely, if ever, gets involved in third-party projects, which he believes signifies its confidence in the prospect.

"The potential returns are enormous. Data indicates that there could be up to 25trn cubic feet of gas, but even if we were just half right and there was 12trn cubic feet, you're still talking about something that is not just transformative for Ireland, but for western Europe."

Between other projects, Providence is currently producing about 150 barrels of oil a day. But O'Reilly wants to see that rise to 2,000 a day so that the company will not have to keep resorting to shareholders to fund new projects.

"We're looking for some onshore production too, but the real value for our shareholders is in Spanish Point and Dunquin. We want to be self sufficient though and we want to get to 2,000 barrels a day within two years. We have the financing in place so we can do that quickly when we have the opportunity to do so."