The West Epsilon jack up rig on Sept. 6 started drilling wells on the 16 well-slot Gudrun steel jacket on Block 15/3 in the central Norwegian North Sea, production license P 025.
Gudrun, discovered with well 15/3-1 S, drilled in 1974-75, lies in 110 m of water about 55 km north of Sleipner. The reservoirs, at a 4,200-4,700 m depth, contain oil in the Upper Jurassic Draupne formation and gas in the Middle Jurassic Hugin formation.
Gudrun will cost about 21 billion kroner to develop.
Statoil plans to drill seven production wells through the jacket into the Gudrun high pressure, up to 820 bar, and high temperature reservoirs before installing the platform topsides in 2013, and starting production in first-quarter 2014.
Statoil said the predrilling the wells would avoid depressurization of the reservoir that would complicate further drilling.
Installation of the 7,000-tonne jacket was completed in August.
A pipeline will transport the production to the Sleipner A gravity-based platform for final processing, with gas piped to the adjacent Sleipner T platform for carbon dioxide removal.
Sleipner A also will supply power to the Gudrun platform.
Statoil estimates that Gudrun contains 127 million boe of recoverable reserves.
Operator Statoil holds a 75% interest in the field with GDF Suez E&P Norge AS holding the remaining 25%.