North Sea focused independent EnQuest's US$3.2billion plan to develop the Kraken heavy oil field has been given the go ahead.
Kraken is in 108-125m water depth, about 135km east of Shetland, and is estimated to contain 137MM bbl gross reserves. EnQuest expects the development, consisting 25 wells tied back to a floating production, storage and offloading vessel (FPSO), to produce, at peak, more than 50,000 boe/d after it comes on stream in 2016-17.
Bumi Armada Berhad is due to be a letter of intent to supply the FPSO, which is to be a conversion of the MV Prisco Alcov, which will be converted by Keppel.
The project, a field development plan for which was been approved by the Department of Energy and Climate today, will have a 25-year plus life, EnQuest said.
EnQuest is the operator, and has a 60% working interest, alongside Cairn Energy (25%) and First Oil (15%).
Discovery
The Kraken fields were discovered in 1985, when Occidental Petroleum drilled an exploration well in the Kraken South area.
Oil was discovered in Heimdal sandstone. Nautical Petroleum appraised this discovery in 2007, with well 9/02b -2 to the north of Kraken South.
The well encountered the same Heimdal sandstone and a further thin oil bearing sandstoneat the base of the Heimdal sequence.
A second appraisal well, 9/02b-3, was drilled in 2008, east of the Kraken Central field. Neither of the Heimdal sandstone reservoirs were present in the 9/02b -3 well.
A third appraisal well, 9/02b- 4 and an exploration well 9/02b- 4Z, were drilled to the south west of the Kraken development area in 2010.
Both wells encountered oil accumulations in Heimdal sandstones. The last appraisal well 9/02b-5 was drilled by Nautical in June 2011. A horizontal reservoir sidetrack wellbore (9/02b-5Z) was also drilled.
In late 2014, EnQuest is also planning to test further upside in the nearby Western Feature 2, containing potentially up to 70-90MM barrels.
The reservoir contains oil and associated gas, with a gas oil ratio (GOR) of approximately 85scf/sbbl. The oil is heavy, approximately 13.7°API crude. The Kraken reservoir is underlain by shale and no formation water or aquifer has been detected in the field.
Development
EnQuest’s field development plan says the firm is planning to develop the Kraken area as three separate fields: Kraken North, Kraken Central and Kraken South, all in Block 9/02b.
There will be 14 horizontal production subsea wells and 11 horizontal water injector subsea wells in the Kraken development area, tied back to an FPSO, from which stabilised crude will be exported via shuttle tankers.
The FPSO power demands will be met through the use of associated gas.
The short fall in associated gas production will be supplemented by the use of either crude oil or diesel. There may be future opportunity for gas import from the Vesterled line.
Hydraulic submersible pumps (HSPs), powered from the FPSO, will be used for artificial lift in all the production wells. These will be provided by SPX, part of ClydeUnion Pumps, based in Glasgow.
Following EnQuest’s acquisition of the Greater Kittiwake area assets, announced recently, Kraken will become EnQuest’s sixth UK North Sea producing hub.
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