15 June - Drilling update - Catcher drill stem test

Premier Oil plc notes that the operator of the Catcher well has today announced that the testing operations on the oil discovery located in the UK Central North Sea Block 28/9 have been completed and the well will now be sidetracked approximately 0.5 kilometres to the east.

The successful well test and fluid sampling programme confirmed 30 degree API gravity oil in the high quality Cromarty reservoir. Oil flowed naturally to surface but no meaningful flow rate could be measured due to mechanical issues most likely due to sand control. The well test revealed a productivity index which reflects excellent average reservoir permeability. Excluding the mechanical issues, the well would have likely flowed at a rate in excess of 7,500 bbl/d. The co-venturers have decided that the information gathered to date is sufficient for development studies to be undertaken.

The sidetrack will target a segment to the east of the Catcher discovery, within the Tay formation.

Premier's recoverable reserves range estimate of 25-50 mmbo for Catcher is unchanged.

15 June 2010

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Notes to editors:

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