Premier Oil Regulatory News (PMO)

PREMIER OIL plc

("Premier" or "the Company")

Carnaby Oil Discovery

6 June 2012

Premier is pleased to announce that the Carnaby exploration well 28/09-5A (Premier equity 50 per cent) has reached a total depth of 4,695 feet and encountered oil.

Initial analysis indicates that the well encountered 51 feet of net oil in the main Tay sandstone within an estimated 86 feet oil column. A core was taken and confirmed oil in excellent quality sandstones. Pressure data and sampling indicates that the API of the oil is 24 degrees and is of similar quality to that established at the nearby Catcher discoveries.  The oil water contact was at the shallower end of expectation; driven by the more complex geology associated with this type of footwall prospect.  The well also encountered 51 feet of Cromarty sands but these were shown to be water wet on the logs.

The high quality data acquisition from the well will now be used to determine what contribution the Carnaby discovery will make to the overall Catcher development.  The well will be plugged and abandoned ahead of the rig moving to drill the high risk Coaster prospect on Block 28/10a, immediately east of the Catcher acreage.

Simon Lockett, Chief Executive Officer, commented:

"The discovery of good quality oil in the western part of the block is encouraging and the results from the Carnaby well will be used to calibrate the remaining exploration potential in this part of the block. In addition, the data from the Carnaby well will contribute to the ongoing development planning for the Catcher Area which continues to move forward focusing on the production of oil from the previous discoveries on Block 28/9a."

Enquiries

Premier Oil plc                                               020 7730 1111

Simon Lockett

Andrew Lodge

Pelham Bell Pottinger                                   020 7861 3232

Gavin Davis

Henry Lerwill