Drilling update - West Rochelle discovery

PREMIER OIL plc

("Premier" or "the Company")

Drilling update - West Rochelle discovery

28 October 2010

Premier is pleased to announce a successful discovery at its West Rochelle well in the UK North Sea. The operator Nexen Inc has today reported that "we have successfully confirmed gas and oil pay in an excellent quality reservoir and are sidetracking the well to further delineate the discovery". Further news is expected shortly following completion of the sidetrack. The West Rochelle discovery is a potential tieback to the Scott field in which Premier has a 21.83% interest.

The well has been drilled on Block 15/26b (Premier interest - 50%) adjacent to the boundary with 15/26c. Premier farmed in to 15/26c acquiring a 25% interest immediately prior to drilling this well.

Enquiries

Premier Oil plc 020 7730 1111

Simon Lockett

Tony Durrant

Pelham PR

Gavin Davis 07910 104 660