New development concept on Oseberg

15/06/2016 When Oseberg Vestflanken 2 starts producing in 2018, it will represent a new concept on the Norwegian shelf. Unmanned wellhead platforms may be relevant for future developments.

The Plan for Development and Operation (PDO) for Vestflanken 2, nine km from the Oseberg field centre in the northern part of the North Sea, was approved by the Ministry of Petroleum and Energy this Tuesday. Vestflanken 2 is the first of three planned phases for development of the remaining reserves in the Oseberg area. This project will help extend the life of the Oseberg field, which has been in production since 1988.

The PDO was submitted in December last year

The development solution chosen for Oseberg Vestflanken 2 is an unmanned wellhead facility resting on the seabed. This platform will have no process equipment, living quarters, drilling facilities or helicopter deck. The wells on the field will be drilled with a mobile drilling unit, while maintenance will be performed with a support vessel with adapted gangway drawing up alongside the platform.

This concept is new on the Norwegian shelf, but common on the Danish and Dutch shelves.

The operator Statoil and partners Petoro, Total and ConocoPhillips have estimated the development cost at NOK 8.2 billion (2015). This investment will enable the production of 17.6 million standard cubic metres of oil equivalents (around 110 million bbls o.e). Of the reserves, the oil makes up nearly 10 million cubic metres (62 million barrels), while the gas reserves amount to 7.8 billion Sm3. The reservoirs are located between 2400 and 3100 metres below the sea surface.

The wellhead facility has ten well slots. To increase the recovery of oil, two of the slots will be used to inject gas. In addition, two production wells will be drilled from an existing subsea template on the Vestflanken. Further injection will take place by bringing in gas through a new pipeline from the gas injection system which already exists in this area. The wells on Vestflanken 2 will be controlled from the Oseberg field centre, where the oil and gas will also be processed.




Illustration: Statoil

Oseberg Vestflanken 2 will be developed with a simplified, unmanned wellhead facility with ten well slots. The licensees have booked a dedicated, simplified, jack-up drilling facility (Cat J rig) to drill the wells.
(Illustration: Statoil)

Updated: 15/06/2016