Offshore staff
LONDON – Pragma Well Technology and Pharis Energy have agreed to jointly pursue development of a high-temperature downhole safety valve, or downhole steam injection valve, in a project backed by the Aberdeen-based Oil & Gas Technology Centre.
Pharis is working on a phased development plan for the heavy-oil Pilot field in block 21/27a in the UK central North Sea, starting with a steam flood trial in the southern part of the field.
If this is successful, Pharis believes recovery of around 120 MMbbl could be feasible, representing roughly 50% of the oil in place and 70 MMbbl more than could be recovered with a typical hot waterflood approach.
According to the partners, offshore steam injection requires development of a downhole safety valve rated for steam injection temperatures of above 300ºC (572°F).
Various downhole components have been designed for the geothermal industry to withstand such temperatures, but steam injection has only been performed offshore in countries with less strict regulations than the UK’s, where to date a downhole safety integrity valve (DSIV) has not been needed.
However, to ensure well integrity for the Pilot program and to comply with all necessary regulations, Pharis is seeking to include a DSIV in the well design. Pragma will design, build, and certify two valves.
Hitherto the application of steam flooding for development of the UK’s offshore heavy-oil fields has been viewed with scepticism in terms of the economics.
However, Pharis estimates steam flooding could enable production of an additional 4 Bboe from already discovered shallow heavy-oil fields in high quality sandstone reservoirs across the UK continental shelf (UKCS), over and above the 800 MMbbl that conventional techniques might recover.
Pharis CEO Steve Brown said: “The application ofsteam flooding offshore has been enabled by the development of technologies to drill, complete, and control horizontal steam injection and production wells.
“These technologies have been pioneered in the SAGD projects in Canada where more than 1,900 horizontal producer injector pairs have been drilled. This valve is the missing ingredient to apply these well technologies offshore and maximize the potential recovery from shallow heavy-oil fields on the UKCS.”
Pharis, formed in 2014 asThe Steam Oil Production Co., is the sole licensee of P2244 and P2320 which together contain more than 400 MMbbl of in-place heavy oil in the Pilot, Blakeney, Harbour, Feugh, Dandy and Crinan fields in blocks 21/27 and 21/28, 140 km (87 mi) east of Aberdeen.
The company is looking to implement the world’s first offshore steam flood project of scale on Pilot, the largest of these fields.
Fina made the original discovery in 1989 and the field has since been appraised with seven reservoir penetrations, including a horizontal well test that flowed more than 1,800 b/d from a short horizontal well.
08/01/2018
