Rockhopper Regulatory News (RKH)

For immediate release: Thursday, 16 January 2014

Rockhopper Exploration plc

("Rockhopper" or the "Company")

Sea Lion Development update

Rockhopper Exploration plc (AIM: RKH), the North Falkland Basin oil and gas exploration company, is pleased to announce that it has completed the concept selection process for the Sea Lion Development with partner Premier Oil ("Premier").

Premier as Operator of the field has recommended the Tension Leg Platform option as the most suitable technical and commercial solution for the development of Sea Lion. Rockhopper has been working closely with Premier and agrees with that recommendation. Premier has also indicated that Final Investment Decision is now likely to be taken in the first half of 2015 and Rockhopper continues to expect first oil 3½ - 4 years after project sanction.

In terms of exploration, the Zebedee, Jayne East, Elaine/Isobel, and Chatham prospects have been matured to drillable status and a rig tender process is underway. This is being conducted in conjunction with other regional operators and includes four firm slots for the Rockhopper / Premier joint venture. Rockhopper expects a contract to be awarded in the first half of this year and the first well to spud in late 2014 or early 2015.

Sam Moody, Rockhopper Exploration's Chief Executive Officer said:

'We are pleased to have reached another significant milestone in the commercialisation of the Sea Lion Field. The Tension Leg Platform provides operational and commercial advantages over the FPSO alternative and it was worth taking the extra time needed to evaluate the option. We now move forward into the Front End Engineering and Development stage with a view to making a final investment decision in 2015.'

Ends.

Enquiries:

Rockhopper Exploration plc

Tel: 0207 016 9571

Sam Moody - Chief Executive (via Vigo Communications)

Peter Dixon-Clarke - Finance Director

Canaccord Genuity Limited (NOMAD and Joint Broker)

Tel: 0207 523 8000

Henry Fitzgerald-O'Connor

Vigo Communications

Tel: 0207 016 9571

Peter Reilly

Patrick d'Ancona

Notes to Editors:

Rockhopper was established in February 2004 with a strategy to invest in and carry out offshore oil exploration to the north of the Falkland Islands. The Company floated on AIM in August 2005 with four offshore production licences: PL023, PL024, PL032 and PL033 which cover approximately 3,800 sq. km. Rockhopper has further smaller interests in licences PL003, PL004a and PL004c, which are operated by Desire Petroleum plc. Additionally, the Company has a significant interest in licence PL004b which contains the extension to the Sea Lion Field as well as the Beverley, Casper and Casper South discoveries.

An extensive work programme was carried out over a number of years on the licences operated by Rockhopper. This has included 2D and 3D seismic and controlled source electromagnetic mapping. In February 2010, the Ocean Guardian drilling rig arrived in Falkland waters to carry out a multi-well drilling campaign. Rockhopper drilled an exploration well on Sea Lion during April and May 2010, the result of which was the first oil discovery and Contingent Resource in the North Falkland Basin. The Sea Lion discovery was successfully tested during September 2010 and June 2011 and was the first oil to flow to surface in Falkland Islands waters. Rockhopper's drilling campaign lasted from 16 April 2010 to 8 January 2012 and resulted in seven successful wells of the ten drilled, with three oil discoveries, three gas discoveries, multiple successful Sea Lion appraisal wells and a successful appraisal well on Casper.

In October 2012 Rockhopper completed a farm-out agreement with Premier Oil plc, whereby Premier Oil acquired 60 per cent. of Rockhopper's interests in its North Falkland Basin licences.

Rockhopper Exploration plc www.rockhopperexploration.co.uk