Exploration firm Fastnet Oil and Gas has said there could be a significant amount of oil in the Celtic Sea, immediately below the Kinsale gas field.

The company holds a 60% stake in deep Kinsale if it commits to a well before the end of September 2015.

Fastnet said it completed its 500km 3D seismic acquisition under the Kinsale field ''significantly'' ahead of schedule and under budget.

This 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. 

Data so far suggests the field may contain up to 2.365 billion barrels of oil in place.

''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,'' commented Paul Griffiths, managing director of Fastnet.

''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 ''anticlinal structure, which has the potential to contain a significant oil accumulation directly beneath the producing Kinsale gas field and the two platforms, in the Celtic Sea''.