Drilling Report

Embargoed for Release: 0700 on 23 April 2013

Wessex Exploration PLC

("Wessex" or "the Company")

Completion of GM-ES-3 Exploration Well

Further to the release on 17 April 2013, Wessex Exploration PLC (AIM:WSX) announces the conclusion of drilling activities on GM-ES-3 (Priodontes) in French Guiana.

At 6,318 metres depth, drilling was terminated. The well had reached sufficient depth to evaluate the deeper potential reservoir, encountering an estimated 65 metres of target formation. With no indications of hydrocarbons the well is now being plugged and abandoned.

The Stena ICEMax will now move on to the GM-ES-4 (Cebus) exploratory well designed to test a different fan system to the previous three wells drilled by the Joint Venture. It is anticipated that the new well will be spudded in early May 2013.

GM-ES-4 is the third well of a four well exploration drilling campaign that commenced in 2012 to follow up the oil discovery at GM-ES-1 in 2011.

Malcolm Butler, Chairman of Wessex stated:

"We look forward to drilling GM-ES-4 on the separate, Cebus fan and continue our programme of delineating potential new prospects through the interpretation of 3-D seismic data on the Central Area."

In accordance with the AIM Rules - Guidance for Mining and Oil & Gas Companies, the information contained in this announcement has been reviewed and signed off by the Chairman of Wessex, Dr Malcolm Butler PhD, BSc, CGeol, FGS who has over 40 years' experience as a petroleum geologist. He has compiled, read and approved the technical disclosure in this regulatory announcement. The technical disclosure in this announcement complies with the SPE/WPC standard.

For further information please contact:

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Notes to Editors on WSX:

Guyane

Wessex holds a net 1.25% interest in the Exclusive Exploration Licence (EEL) covering an approximate 24,100 sq.km offshore area of Guyane (a French prefecture previously known as French Guiana). The EEL interest is held via a 50/50 joint venture between Wessex and Northern Petroleum Plc, using Northpet Investments Limited as the holding company with a total interest of 2.5%. The other partners in Guyane are Shell (45% and operator), Tullow (27.5%) and Total (25%).

Juan de Nova

Wessex holds a 70% interest in the Juan de Nova Est Permit, covering 9,010 sq. km in water depths ranging from 200m to 3,000m, to the east of Juan de Nova Island in the Mozambique Channel. Wessex has been designated as operator, subject to the approval of the French authorities. Global Petroleum Limited (AIM: GBP, ASX: GBP) has a 30% interest.

Southern United Kingdom

Wessex holds three licences in southern United Kingdom - PEDL 238: 50%; PEDL 239: 25%; P1928: 35% - alongside its partner and operator, NWE Mirrabooka (UK) Pty. Ltd (a fully owned subsidiary of ASX listed Norwest Energy NL).

Saharawi Arab Democratic Republic (SADR, Western Sahara)

Wessex holds three blocks - Bojador (39,983 sq.km), Guelta (15,760 sq.km) and Imlili (16,955 sq.km) - under Assurance Agreements which cause Production Sharing Contracts to come into effect once the SADR government is able to take control of the territory. Wessex is the designated operator and holds a 50% interest; Tower Resources (AIM: TRP) has the other 50% interest.