The well was drilled to a total measured depth of 11,530ft, approximately 1km to the southeast of the original 2008 discovery well.
The company said that the well has established oil down to 9,643ft subsea and no oil-water contact has been penetrated.
The original discovery well and the two side-tracks indicate a hydrocarbon column in excess of 425ft.
Once the current operations are completed, the JW McLean rig will be released from the Cladhan location.
The next step in the appraisal of Cladhan will be to analyze all of the data gathered in order to decide on the next drilling location and perform a site survey.
It is possible that the next phase of drilling at Cladhan could commence in the fourth quarter of 2010 dependent upon rig availability, otherwise drilling will resume at Cladhan early next year.