ExxonMobil has commenced a EUR125m ($160m) drilling activity over two prospects at the Dunquin licence area in the Porcupine Basin, 200km offshore Ireland.

Based on earlier data, which suggested the presence of nearly 300 million barrels of oil and 8.5 trillion cubic feet of gas between the two Dunquin prospects, ExxonMobil is planning to drill test wells over a four-month period.

The prospects, if proven and extracted, could be one of the biggest ever global discoveries of oil and gas and is expected to change Ireland’s economic fortunes, reported Independent.ie.

Drilling over Dunquin prospects, which are situated in the Atlantic where the ocean is 1.6km deep, is a much anticipated programme and is eagerly watched by oil companies across the globe.

In March 2008, Irish independent oil and gas exploration company Providence Resources, along with ExxonMobil and UK-based Sosina Exploration, was awarded two exploration licences in Porcupine Basin.

The licences in the Porcupine Basin comprise 13 blocks across 760,000 acres, located in water depths of at least 6,500ft.

In June 2009, Providence announced that it will start site survey work on the Dunquin acreage in Porcupine Basin.

ExxonMobil and Italian firm Eni, hold 27.5% interest each in the Dunquin prospect, while Spanish energy firm Repsol, UK-based Sosina and Providence Resources has 25%, 4% and 16% interest, respectively in the prospect.