Statoil AS plans to extend the producing life of its Norwegian North Sea Sleipner West field by combining a major topsides modification of the Sleipner T platform with a multiwell subsea tieback of the Alpha North gas and condensate reservoir on the field's north flank.
It picked the 2.6 billion-3 billion kroner ($290 million-$330 million) development -- aimed at boosting compression capacity at Sleipner West to offset declining reservoir pressure -- over the original scheme and install a compressor platform at the field.
Opting for the lower cost modification project is not expected to undermine the recovery factor at Sleipner West, said Statoil Project Manager Aoued Kaddour. And beyond the financial and technical gains, the revamp will provide environmental benefits because CO2 emissions, noted Kaddour, will be "more than halved."
Tying back the Alpha North gas-condensate reservoir via a "seabed template and 4-5 wells" is an integral part of attempts to answer the need for increased compression capacity and production at Sleipner. The scheme was "sketched out" in the plan for development and operation of Sleipner West originally submitted to the Ministry of Petroleum.
According to Kaddour, the application to revamp the development plan with the new scheme will be give the ministry at the end of June.
Statoil is scheduling Sleipner West to start producing at a lower pressure in the autumn 2002, while Alfa North is expected to come on stream 2 years later.
Sleipner West, which is on Norwegian North Sea Blocks 15/6 and 15/9, came into production in August 1996, some 3 years after Sleipner East.
Statoil holds a 17.13% stake in Sleipner West. Other partners are the state's direct financial interest with 32.37%, ExxonMobil Corp. 32.24%, Norsk Hydro AS, 8.85%, and TotalFinaElf SA 9.41%.