Statoil ASA has started production from the low-permeability Smorbukk South Extension of Asgard oil and gas field in the Norwegian Sea with what it claims to be the first use of “fishbone” multilateral technology offshore Norway (OGJ Online, Mar. 20, 2013).
Because of low permeability and porosity described as “ranging from bricks to tiles,” Statoil could not fracture the reservoir. It instead used a well with a long horizontal section from which 150 “bones,” each 10-12 m long, were drilled. The Odfjell Drilling Deepsea Bergen jack up handled drilling.
The technology achieved 5,200 m of reservoir exposure, Statoil said.
The company didn’t report the production rate. It estimates reserves at 16.5 million boe.
Discovered in 1985, the reservoir was long considered too tight to develop. Statoil said it might drill a gas-injection well.
The Asgard partnership includes Statoil Petroleum AS with 34.57%; Petoro AS, 35.69%; Eni Norge AS, 14.82%; Total E&P Norge AS, 7.68%; and ExxonMobil Exploration & Production Norway AS, 7.24%.