Production Commenced at Operated Well in Oklahoma

Magnolia Petroleum Plc / Index: AIM / Epic: MAGP / Sector: Oil & Gas 5 June 2013 Magnolia Petroleum Plc(`Magnolia' or `the Company') Commencement of Production at Magnolia Operated Well in Mississippi Lime Formation, Oklahoma and Operations Update Magnolia Petroleum plc, the AIM quoted US onshore focused oil and gasexploration and production company, is pleased to report an update on theCompany's activities in proven US onshore formations such as the Bakken/ThreeForks Sanish, North Dakota, and the Mississippi Lime and Woodford/Huntonformations in Oklahoma. Update on the Magnolia Operated Roger Swartz Vertical Well, Oklahoma Following the fracture stimulation of the Magnolia operated, 100% owned RogerSwartz #1 vertical well (`Roger Swartz' or `the Well') targeting theMississippi Lime formation, an initial production rate (`IPR') of 17 bopd hasbeen recorded, which is in line with management's expectations. To date, theCompany is pleased to report that 338 barrels of oil recovered by Roger Swartzhave been sold. The total cost of the Well including drilling, completing andstimulating costs came in on budget at approximately US$730,000. Roger Swartz is currently producing from the Mississippi Lime formation fromwhich the Company estimates a total of up to 51,000 barrels of oil equivalentare recoverable. The Directors believe there is a potential payzone up holeknown as the Vertz, which holds an additional 10,000 barrels of recoverablereserves. Once all production has been recovered from the Mississippi Lime, theCompany intends to move up hole and complete in the Vertz. Commencement of Production The Company has been informed by the relevant operator that production hascommenced at the following well, with the IPR as set out below: Well Name Formation Operator Gross IPR Magnolia's Net IPR NRI Flinders Mississippi Redfork 143 boepd 1.848 2.64 boepd1-25H Lime, Oklahoma Participation in new wells The Company is pleased to announce that it is participating in the followingnew wells: Well Name Targeted Formation Operator Magnolia's Net Cost to WI/NRI Magnolia Omega 1-33H Hunton, Oklahoma Equal Energy 1.066%/ US$36,255 0.799% N. Cana Filler Woodford, Oklahoma Newfield 0.390%/ US$43,6281H-34X 0.293% Smith Trust Woodford, Oklahoma Marathon Oil 0.065%/ US$7,5661-2H 0.049% Rita Whittington, COO of Magnolia, said, "The commencement of production atRoger Swartz, our first vertical well drilled as operator, is a major milestonefor Magnolia. The initial production rates are in line with our expectations,while the identification of another potential payzone, the Vertz, adds to theattractive economics of the Well and highlights the multiple horizons thatexist in Oklahoma. Drilling as operator complements our strategy ofparticipating in new wells in proven US onshore formations with other operatingcompanies such as Devon Energy and Marathon Oil, as we look to increase netproduction, prove up reserves on our 13,500 plus net mineral acres and, in theprocess, generate significant value for shareholders." Existing well updates The Company has been informed by the relevant operators of a change in statusin the following wells in which it is participating: Well Formation Status NRI % Operator Cordray-Ritter Mississippi Completed and 0.597 Chesapeake4-28-14 1H Lime, Oklahoma waiting on initial Energy production rates Gustafson 31-30H Bakken, North Frac scheduled for 4.071 Marathon Oil Dakota 7 June 2013 Helgeson 41-30H Bakken, North Frac scheduled for 4.071 Marathon Oil Dakota 11 June 2013 Blaser 1-10H Mississippi Drilling 9.375 Cummings Lime, Oklahoma JKL 1-08 H* Mississippi Drilling 1.305 Devon Energy Lime, Oklahoma JKL 1-04 H** Mississippi Drilling 0.333 Devon Energy Lime, Oklahoma *JKL 1-08 H well was previously known as ?1-08H **JKL 1-04 H well was previously known as ?1-04 H ** ENDS ** Glossary `boe' means barrels of oil equivalent: a unit of energy based on theapproximate energy released by burning one barrel (42 US gallons or 158.9873litres) of crude oil. There are 42 gallons (approximately 159 litres) in one barrel of oil, whichwill contain approximately 5.8 million British Thermal Units (MBtus) or 1,700kilowatt hours (kWh). The value is necessarily approximate as various grades ofoil have slightly different heating values. BOE is used by oil and gascompanies in their financial statements as a way of combining oil and naturalgas reserves and production into a single measure. `boepd' means barrels of oil equivalent per day `bopd' means barrels of oil per day `WI' means working interest `NRI' means net revenue interest For further information on Magnolia Petroleum Plc visitwww.magnoliapetroleum.com or contact the following: Steven Snead Magnolia Petroleum Plc +01 918 449 8750 Rita Whittington Magnolia Petroleum Plc +01 918 449 8750 Jo Turner / James Caithie Cairn Financial Advisers LLP +44 20 7148 7900 John Howes / Alice Lane / Luke Northland Capital Partners +44 20 7796 8800Cairns Limited Lottie Brocklehurst St Brides Media and Finance +44 20 7236 1177 Ltd Frank Buhagiar St Brides Media and Finance +44 20 7236 1177 Ltd Notes Magnolia Petroleum Plc is an AIM quoted, US focused, oil and gas explorationand production company. Its portfolio includes interests in 112 producing andnon-producing assets, primarily located in the highly productive Bakken/ThreeForks Sanish hydrocarbon formations in North Dakota as well as the oil richMississippi Lime and the substantial and proven Woodford and Hunton formationsin Oklahoma. Summary of Wells Category Number of wells Producing 112 Being Drilled / Completed 15 Elected to participate / waiting to 27spud TOTAL 154 This table excludes four out of six wells acquired as part of the acquisitionof 800 gross acres with a 100% working interest in Osage County, Oklahoma, asannounced on 10 February 2012. These four wells are currently `shut in' andwill require a workover programme at some point in the future to bring backinto production.