ExxonMobil extensively upgrades its Norwegian Sleipner West field
While the North Sea is without doubt seeing an increasing number of smaller independents becoming involved in the
region, the massive conglomerates are still making their own contributions.
For one, ExxonMobil Exploration and Production Norway has participated in an extensive upgrade program at the
Norwegian Sleipner West field, which is expected to boost the estimated recoverable resources by an impressive 350 mm
oil-equivalent barrels.
Esso Exploration and Production Norway is one of three companies that fall under ExxonMobil in Norway. The other two
are Mobil Exploration Norway and Esso Norge.
ExxonMobil is the fourth largest oil and gas producer on the Norwegian Continental Shelf, having equity in around 20
gas and oil fields in production, and about 10 % interest in Norwegian infrastructure for gas transportation and
treatment. The company is the largest international investor on the Norwegian shelf and operates the Balder, Jotun,
Ringhorne and Sigyn fields.
The Sleipner West field has over the past months gone through an extensive maintenance and upgrading program, which
has resulted in increased reserves and prolonged plateau production by three years.
The Sleipner T treatment platform, located on Sleipner East, was converted to deal with declining reservoir pressure.
The purpose of this was to help keep Sleipner West's daily gas production at its plateau level of 22 mm cm for
another three years. It also boosted recoverable reserves in the field by 45 bn cm of gas and 88 mm barrels of
condensate (light oil).
The new ExxonMobil Exploration and Production program will help keep Sleipner West's gas production at its plateau
level of around 775 mm cfpd. This ExxonMobil Norwegian subsidiary has a 32 % equity stake in the field, which is
operated by the Norwegian company, Statoil.
"A key part of this upgrade is the Sleipner West Alpha North satellite development, which includes the installation
of a subsea template and the drilling of four wells," says Kathy Pepper, Production Manager and Country Lead for
ExxonMobil in Norway. "We are pleased with improvements and upgrades at Sleipner West that have contributed to
maintaining a high production level." She adds that ExxonMobil, together with the operator and the other licensees,
has executed the Sleipner West project at lower costs than originally specified in the plan for development and
operation.
The Sleipner West Alpha North satellite project was apparently completed on time and at a cost of about $ 350 mm,
some 25 % below the original estimate. In addition to the Sleipner Alpha North satellite development, the upgrade
program includes the Sleipner West compression project. Through this project, the existing Sleipner T platform has
been modified to accommodate compression, for cost savings of $ 380 mm versus the cost of building a new
platform.
The Alpha North gas and condensate structure on the Sleipner West field in the North Sea began production just over
24 months after the project was sanctioned. This development was brought on stream with one subsea template and four
wells.
The seabed facility stands about 18 km north-west of the Sleipner platforms. A 16-inch pipeline transfers the
wellstream to the Sleipner T gas treatment installation on Sleipner East for processing. Recoverable reserves in the
satellite structure are put at about 13 bn cm of gas and some 32 mm barrels of condensate.
Licensees on Sleipner West are Statoil, with a 49.5 % holding, ExxonMobil with 32.34 %, Total with 9.41 % and Norsk
Hydro with 8.85 %.