The Balmoral oil field is a depleted crude oil field in the UK sector of the central North Sea, 225 km north-east of Aberdeen. Oil was produced from the field reservoir by the Balmoral Floating Production Vessel (FPV) between 1986 and 2020. The Balmoral FPV also processed oil from six minor oil fields in the area. Oil production from the field has ceased.
The field The Balmoral oil field is located in Block 16/21 of the UK North Sea continental shelf. The field was discovered in August 1975; the oil reservoir comprises Upper Paleocene and Devonian sandstones at a depth of . The reservoir and its fluids have the following characteristics: +Balmoral reservoir and fluidsParameterValueAPI gravity39.9°APIPorosity17-28%Permeability3,300 mdSulfurNilInitial recoverable reserves 68 million barrels, 13.33 million tonnes
Owners and operators The joint venture owners of the field in 1994 were Sun Oil Britain Ltd (62.0%), Deminex UK Oil and Gas Ltd (15.0%), Clyde Expro plc (15.0%), Pentex Oil Limited (8.0%). Sun Oil operated the Balmoral field. In 2004 Canadian Natural Resources (CNR) acquired a 70.2% interest in the field; in 2007 Oilexco acquired the stake from CNR; in 2009 Premier Oil E&P UK Ltd acquired Oilexco and Premier Oil becomes the operator of the Balmoral field.
Development The Balmoral field was developed by a single custom built integrated production and accommodation semi-submersible vessel. The principal design data of the Balmoral FPV was as follows. +Balmoral FPV design dataCoordinates58.229186N 1.108617EWater depth143–147 metresTypePurpose-built semisubmersible GVA 5000FunctionProduction and accommodationFPV design and fabricationGotaverken Arendal, Gothenburg; Highland Fabricators, NiggTopsides design Bectel Great Britain LtdDisplacement33,000 tonnesAnchoring8 point, 4 thrustersAccommodation120 crewWell slots14 on template + other remoteWells12 production, 6 water injectionOil throughput65,000 barrels per dayOil storageNoneWater injection100,000 barrels per dayFPV installed1986Production startedNovember 1986Oil production toBrae-Forties trunk line via 14.5 km 14-inch pipelineGas production toOn board fuel gas and lift gas, excess flared
Small oil fields in the vicinity of Balmoral were developed with subsea wellheads. Well fluids were transported by pipeline from the wells to the Balmoral FPV for treatment and export. +Small oil fields producing to Balmoral FieldBeaulyBrendaBurghleyGlamisNicholStirlingLocation16/2115/25b16/22162115/25a16/21ReservoirPaleocene sandsPaleocene sandsPaleocene sandsLate JurassicPaleocene sandsDevonian sandstoneOwnersTalisman; Repsol SinopecOilexco Inc; Premier Oil E&P UK Talisman; Repsol SinopecPremier Oil E&P UK Oilexco Inc; Premier Oil E&P UK Premier Oil E&P UK Wells151315First oil200020072010198720071995Peak production 10,000 bpd30,000 bpd1,300 bpd10,200Production to9.3 km pipeline to Balmoral8 km pipeline to Balmoral17.3 km pipeline to Balmoral4.7 km pipeline to Balmoral9.5 km pipeline to Brenda11.1 km pipeline to Balmoral
Processing plant Oil from the wellheads was routed to two stages of 3-phase (oil, gas, water) separators where gas and water were removed. Oil was metered and pumped via a 14.5 km 14-inch diameter flexible riser and pipeline to a tie-in on the Brae–Forties trunk line and thence to Cruden Bay.
The peak production from Balmoral was 1.71 million tonnes per year in 1987. In 1991 the production rate was 35,000 bpd.
Gas from the separators was compressed and used as fuel gas and lift gas for a number of wells.
Water injection facilities for up to 100,000 bpd were provided to maintain reservoir pressure through six injection wells.
Decommissioning A Cessation of Production application was received from the Oil and Gas Authority on 23 April 2018. Premier Oil prepared a decommissioning plan. Production from Balmoral ceased on 28 November 2020. The FPV was flushed to remove hydrocarbon. It was removed from the field in May 2021 and was taken to Denmark for dismantling and recycling of materials.
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