Exploration drilling update

PREMIER OIL plc

("Premier" or "the Company")

Exploration drilling update

13 April 2012

Indonesia

The Biawak Besar-1x exploration well (Premier equity 28.67 per cent) on Natuna Sea Block A has reached a total depth of 5,950 feet MD and will be plugged and abandoned. The seismic amplitude supported Miocene target was encountered on prognosis and the logs showed better than expected sand quality. However, the sands were water wet. The results of the well will be incorporated into the existing 3D seismic database to determine the cause of the amplitude response and its implications for the future prospectivity of the targeted play.

Elsewhere in Indonesia Benteng-1, a frontier exploration well on the Buton Block (Premier equity 30 per cent), is currently drilling and the results are expected in June.

UK

Premier continues to seek to push the boundaries of the proven play types wider and deeper in the Central UK North Sea. Notably, the Stingray well (UK Block 15/13b, Premier equity 50 per cent) was spudded on 9 April and the results are expected in May while the Carnaby prospect on the Premier-operated Catcher acreage (UK Block 28/9, Premier equity 50 per cent), will be drilled by the Sedco 711 rig early next month. The rig will then drill the Coaster prospect (Premier equity 50 per cent) on neighbouring UK Block 28/10a.

Simon Lockett, Chief Executive Officer, commented

"The first three months of 2012 has seen much activity on the Premier-operated Natuna Sea Block A. In addition to internally sanctioning the Pelikan and Naga projects, we have drilled two potential play opening wells, Anoa Deep and Biawak Besar. Continuing exploration on Block A will now focus on the exploitation and significant follow on potential of the Anoa Deep well.

In the UK, our exploration focus turns to the Stingray well which is currently drilling and the Carnaby well, which we expect to spud soon."

Enquiries

Premier Oil plc 020 7730 1111

Simon Lockett

Andrew Lodge

Pelham Bell Pottinger 020 7861 3232

Gavin Davis

Henry Lerwill