Shares in Fastnet Oil and Gas gained yesterday after the exploration firm said there could be a significant amount of oil in the Celtic Sea which is immediately below the Kinsale gas field.
The company holds a 60pc stake in the company's Deep Kinsale prospect if it commits to a well before the end of September 2015. Shares rose 3.3pc to 24 pence during trading in London yesterday.
The shares did not trade in Dublin where it also has a listing.
The Deep Kinsale prospect is a series of reservoirs, like those at the nearby Barryroe field.
Fastnet said yesterday that it has completed a 500 square kilometre 3D seismic programme. The work was significantly under budget, it added. An independent assessment estimated Deep Kinsale's unrisked 'best case', or P50, prospective resources at 2.365bn barrels of oil in place.
The 3D programme will be used to further refine the work started by the analysis of the 2D data. It will be applied to increasing the chance of geological success.
"While there is always inherent risk associated with early stage exploration, we believe that our successful efforts to de-risk the assets will allow us to achieve our objectives of creating significant value through initial drilling and securing a strategic farm-out transaction,'' Fastnet managing director Paul Griffiths said.
"In line with this approach we are working to ensure that a potential farm-in well, combined with high quality 3D seismic definition of structure and reservoir "sweet spots", delivers the results necessary for an economically viable pilot development at today's oil prices,'' he added.
John Craven, a founder shareholder of Fastnet, said that Deep Kinsale is a large "anti-clinal structure, which has the potential to contain a significant oil accumulation directly beneath the producing Kinsale gas field and the two plat- forms, in the Celtic Sea''.