Strengthening the gas machine
Several important new components will be added to Statoil’s gas machine when the next gas year begins today, 1 October – including longer plateau production and more reserves for Sleipner West.
Another contribution to the group’s position as a strong gas player comes from its Kvitebjørn development in the North Sea, which began producing on 26 September.
The improvement for Sleipner West, also in the North Sea, follows from an extensive maintenance and modification turnaround during the autumn.
This incorporated the Sleipner West compression and Alpha North satellite project, which represents phases two and three of the field development.
The Sleipner T treatment platform, which stands on Sleipner East and is tied to the A installation by a bridge, was converted to deal with declining reservoir pressure.
That will help to keep Sleipner West’s daily gas production at its plateau level of 22 million cubic metres for another three years.
It has also boosted recoverable reserves in the field by 45 billion cubic metres of gas and 88 million barrels of condensate (light oil).
Preparations were also made in the turnaround to receive gas and condensate from Alpha North via a subsea template and four wells tied to Sleipner T by an 18-kilometre pipeline.
“The overall project has been executed more cost-effectively than originally specified in the plan for development and operation,” says Sleipner operations vice president Kyrre Nese.
“Instead of building a new compressor platform, we’ve modified the existing structure – cutting NOK 2.5 billion from the cost to the licence.”
He emphasises that the Sleipner fields have been strengthened as a gas transport hub, both to continental Europe and to the UK.
The Ormen Lange field operated by Norsk Hydro in the Norwegian Sea is due to begin producing gas from 2007, which will be piped to the UK via the Langeled line and the Sleipner Riser platform.
“The advantage of sending Ormen Lange production via Sleipner R is that gas from the two fields can be mixed, improving robustness in terms of quality for both,” says Mr Nese.
“Sleipner East and West will be additionally strengthened as a gas hub for many years to come, while having the flexibility to reach both continental and British customers.”
Gas and condensate production from Sleipner West resumed as planned on 19 September after the turnaround had been completed as planned in 33 days.
Alpha North is due to come on stream around 10 October, initially helping to boost condensate output.
Technically recoverable reserves in the satellite field are put at roughly 13 billion cubic metres of gas and about 32 million barrels of condensate.
Some 30 million barrels of Sleipner condensate are piped annually to the Kårstø processing complex operated by Gassco north of Stavanger, with Statoil as technical service provider.