Completion of GM-ES-4 Exploration Well

Embargoed for release: 0700 on 23rd July 2013 Northern Petroleum Plc ("Northern" or "the Company") Completion of GM-ES-4 Exploration Well Further to the release on the 8th May 2013, Northern Petroleum Plc (AIM: NOP)announces the conclusion of drilling activities on the GM-ES-4 well in FrenchGuiana. The well penetrated the primary and secondary reservoir objectivesbefore drilling operations were concluded at a total depth of 6,292m. Theresults of the wireline logging programme have confirmed the presence ofreservoir, however no evidence of hydrocarbons is seen from the drilling orwireline log data. The well is now being plugged and abandoned. The Stena ICEMax will now drill the GM-ES-5 exploration well which will belocated on the Cingulata fan in which the Zaedyus discovery was made in 2011.The well is designed to explore deeper targets within the Cingulata fan complexand will also test the potential downdip extension of the GM-ES-1 discovery. GM-ES-5 is the last in a four well exploration drilling campaign that commencedin mid 2012 to follow up the Zaedyus oil discovery made in 2011. Northern, through holding 50 per cent of Northpet Investment Limited, owns anet 1.25 per cent interest in the offshore exploration licence `GuyaneMaritime'. Northern is in partnership with Shell (Operator, holding 45 percent), Total (25 per cent), Tullow Oil (27.5 per cent) and Wessex Exploration(also holding 1.25 percent through owning the remaining 50 per cent interest inNorthpet Investment Limited). Keith Bush, Chief Executive Officer of Northern, stated: "Whilst the GM-ES-4 well has not encountered hydrocarbons, the data from thiswell and the previous wells drilled to date will be integrated with the new`Central Slope' 3D seismic volume covering in excess of 4,300 squarekilometres. This additional information will allow the partnership to furtherde-risk the prospect portfolio held under licence in the Guyane Maritimepermit. I now look forward to the drilling of the GM-ES-5 well and theopportunity that it presents the Company and Shareholders." In accordance with AIM Rules - Guidance for Mining and Oil & Gas Companies, theinformation contained in this announcement has been reviewed and signed off bythe Exploration and Technical Director of Northern, Mr Graham Heard, CGeol.FGS, who has over 35 years' experience as a petroleum geologist. He hascomplied, read and approved the technical disclosure in this regulatoryannouncement. The technical disclosure in this announcement complies with theSPE/WPC standard. For further information please contact: Northern Petroleum Plc Tel: +44 (0)20 7469 2900Keith Bush, Chief Executive OfficerGraham Heard, Exploration & Technical Director Westhouse Securities (Nomad and Broker) Tel: +44 (0)20 7601 6100Richard Baty - Corporate FinanceIan Napier - Corporate Broking FTI Consulting Tel: +44 (0) 20 7831 3113Edward Westropp Bishopsgate Communications Tel: +44(0)20 7562 3350Nick Rome Notes to Editors: Northern is a full cycle oil and gas company currently holding numerouslicences in a number of low risk areas and is continuing with its strategy ofadding and securing value for shareholders as it engages with projects at allstages of the E&P value chain. Comprehensive information on Northern and its oil and gas operations, includingall press releases, annual reports and interim reports are available fromNorthern's website at www.northpet.com.