Independent Assessment of Horse Hill-1 Well

5 June 2015 Doriemus plc ("Doriemus" or the "Company") Independent Assessment of Horse Hill-1 Well The Board of Doriemeus plc (AIM: DOR) announces that Schlumberger, one of theleading suppliers of technology, integrated project management and informationsolutions to customers working in the global oil and gas industry, hasindependently assessed the petrophysics of Horse Hill-1 well ("HH-1"), locatedin PEDL137 in the Weald basin near to London Gatwick Airport, in which theCompany has net attributable interest of 6.5%. The report, entitled Petrophysical Evaluation of the Horse Hill-1 Well,estimates an overall Oil in Place ("OIP") for the Jurassic section of the wellto be 271.4 million barrels of oil ("MMBO") per square mile. The total OIPcomprises 16.2 MMBO per square mile for the conventional Upper Portland Sandreservoir discovery and 255.2 MMBO per square mile solely for the tightlimestone and mudstone plays of the Kimmeridge, Oxford Clay and Lias. The OIPhydrocarbon volumes estimated should not be construed as recoverable resourcesor reserves. The report, which is addressed to UK Oil & Gas Investments plc ("UKOG") isavailable on UKOG's website www.ukogplc.com. Doriemus' interest in Horse Hill: The Horse Hill-1 well is located within onshore exploration License PEDL137, onthe northern side of the Weald Basin near Gatwick Airport. Doriemus owns a 10%direct interest in Horse Hill Developments Ltd. HHDL is a special purposecompany that owns 65% participating interests and is the operator of licencePEDL137 and the adjacent licence PEDL246 in the UK Weald Basin. The remaining35% participating interests in the PEDL137 and PEDL246 licenses are held byMagellan Petroleum Corporation. Donald Strang, Doriemus' Chairman, commented: "This independent technical viewpoint adds further weight to the potentialsignificance of the HH-1 well and the potential of the Horse Hill licences." Schlumberger is acting exclusively for UKOG and for no one else in connectionwith the subject matter of this announcement and will not be responsible toanyone other than UKOG in connection therewith. No person or company other thanUKOG may directly or indirectly rely upon the contents of its report.Schlumberger is acting in an advisory capacity only and, to the fullest extentpermitted by law, disclaims all liability for actions or losses derived fromany actual or purported reliance on its report (or any other statements oropinions of Schlumberger) by any person or entity other than UKOG. Restoration of trading Restoration of trading in the Company's shares is scheduled for today, 5 June2015. For further information please contact: Doriemus plcDonald Strang/Hamish Harris +44 (0) 20 7440 0640 Cairn Financial Advisers LLP:James Caithie / Sandy Jamieson/ Carolyn Sansom +44 (0) 20 7148 7900 Public Relations: +44 (0) 20 7929 5599Square 1 Consulting LtdDavid Bick/Mark Longson Glossary: conventional oil a play where oil is found or expected to be present withinplay a conventional reservoir. The term can be applied to a play where the trapped petroleum is defined by a discovered discrete petroleum accumulation or play related to localized geological structural features and/or stratigraphic condition, typically with the accumulation bounded by a downdip contact with an aquifer, and which is significantly affected by hydrodynamic influences such as the buoyancy of petroleum in water. conventional a reservoir normally with an average permeabilityreservoir exceeding 1 milliDarcy. discovery a discovery is a petroleum accumulation for which one or several exploratory wells have established through testing, sampling and/or logging the existence of a significant quantity of potentially moveable hydrocarbons limestone a sedimentary rock predominantly composed of calcite (a crystalline mineral form of calcium carbonate) of organic, chemical or detrital origin. Minor amounts of dolomite, chert and clay are common in limestones. Chalk is a form of fine-grained limestone. mudstone an extremely fine-grained sedimentary rock consisting of a mixture of predominantly clay plus silt-sized particles. oil initially in the quantity of oil or petroleum that is estimated toplace or exist originally in naturally occurring accumulations before any extraction or productionoil in place play a set of known or postulated oil and or gas accumulations sharing similar geologic, geographic, and temporal properties, such as source rock, migration pathways, timing, trapping mechanism, and hydrocarbon type recoverable those quantities of petroleum (oil in this case)resources estimated, as of a given date, to be potentially recoverable from known accumulations reserves those quantities of petroleum anticipated to be commercially recoverable by application of development projects to known accumulations from a given date forward under defined conditions; reserves must further satisfy four criteria: they must be discovered, recoverable, commercial and remaining (as of the evaluation date) based on the development project(s) applied; reserves are further categorized in accordance with the level of certainty associated with the estimates and may be sub-classified based on project maturity and/or characterised by development and production status reservoir a subsurface rock formation containing an individual natural accumulation of moveable petroleum. tight oil play a play where oil is found or expected to be present within a reservoir with low permeability i.e. a tight reservoir. The term in the case of HH-1, is applied to a play where trapped petroleum accumulations are expected to be pervasive throughout a large area and that are not significantly affected by hydrodynamic influences (also called "continuous-type deposits"). END