Celtic Sea


Hook Head, Helvick, and Dunmore


Hook Head



Celtic Sea, basic data


North Celtic Sea Basin

License number

SEL 2/07

Part Blocks

49/9, 50/6, 50/7 and 50/11


Discovery Appraisal and Exploration


Providence Resources


Celtic Sea, partner shares






(former ABT Oil & Gas) 


Oil & Gas



Hook Head 

72.5 %

18.3333 %   

9.1677 %


72.5 %

18.3333 %    

9.1677 %


62.5 %

18.3333 %  10 %  *) 

9.1677 %


 *) Subject to Ministerial consent.


The Hook Head discovery lies approximately 60 kilometres off the south coast of Ireland, in 70m of water. In 1971, Marathon drilled the 50/11-1 well which encountered five hydrocarbon bearing reservoirs. Due to operational difficulties at the time, the well was not tested and various uncertainties (hydrocarbon type, commerciality, etc) remained.


In July 1998, Providence acquired a high resolution 2D seismic survey over the prospect, confirmed the 4-way dip closure and demonstrated that the original discovery well was drilled some way off the crest.


Crestal appraisal well 50/11-3 was drilled in September 2007 by the group and a significant hydrocarbon column (56ft net) was encountered in the Lower Cretaceous Wealden Group. Operational difficulties resulted in an inconclusive test, with hydrocarbons and water flowing from multiple zones.


The 2008 drilling campaign included drilling of two wells, namely 50/11-4 on Hook Head, and a second well (50/6-4), drilled on the nearby Dunmore oil accumulation. Although hydrocarbons were logged in 50/11-4, the interpreted volumes were significantly less than prognosed so the well was plugged and abandoned. Dunmore well 50/6-4 unexpectedly encountered hydrocarbons within a thin carbonate horizon in the Wexford formation but the primary Jurassic reservoir interval was water bearing.

In late 2010, Nautical Petroleum farmed into the Ardmore acreage (now renamed Nemo) with the aim of appraising the development feasibility of the heavy oil underlying the gas discovery.


In October 2010, SOSINA agreed to carry out a number of studies on the potential appraisal drilling and development feasibility of the Hook Head discovery in return for additional equity, earned by sidetracking and testing the main reservoir sand. Current operator estimates based on re-mapping of the Hook Head structure suggest contingent reserves of 48 MMbbl.