Valhall developments year by year

9 October 2000: production licence 006 B awarded for Valhall, block 2/8. The licence was set to run until 31 December 2028, with BP Amoco Norge AS as operator.

November 2000: production licence for Valhall extended from 2011 to 2028 in connection with the plan for development and operation (PDO) covering the water injection project.

4 May 2001: production licence 033 B awarded for Hod, block 2/11. The licence was set to run until 31 December 2028, with BP Amoco Norge AS as operator.

9 November 2001: PDO for the Valhall flanks approved. The flanks were developed with two unstaffed platforms tied back to the existing installations located centrally on the field. BP Amoco Norge AS was operator for the development. The total investment was specified in the PDO as NOK 4 164 million in 2001 value.

Summer 2003: water injection platform Valhall IP installed. It was linked by a bridge to the Valhall WP wellhead platform. Drilling equipment on the IP could be used over the wells on the WP.

Also known as the Valhall WIP water injection platform, this installation has a steel jacket built at Aker Verdal and a topside fabricated by Aker Stord.

Equipment on the IP included two GE gas turbines, each with an average output of 20 megawatts (MW) and an efficiency of about 32 per cent.

May 2003: Valhall flank south on stream. This unstaffed wellhead platform sits six kilometres south of the Valhall field centre. It was designed by Heerema, with the jacket fabricated at Vlissingen in the Netherlands and the topside built in Tønsberg.

2003: continuous seabed seismic surveying initiated on Valhall. The seabed over the field was covered with 120 kilometres of seismic cables and umbilicals for continuous monitoring of reservoir behaviour.

This life of field seismic (LoFS) installation ensures the delivery of recoverable reserves and increases both the recovery factor and production.

It means fewer dry wells and lays the basis for real-time reservoir management. Data are transferred via fibreoptic cables to a multidisciplinary team on land.

7 January 2004: Valhall flank north on stream. This unstaffed wellhead platform sits six kilometres north of the Valhall field centre.

It was designed by Heerema and installed by that company in July 2003, with the jacket fabricated at Vlissingen in the Netherlands and the topside built in Tønsberg.

July 2007: BP Norge awarded a contract to oil service company Subsea 7. Covering construction and installation of two new flowline systems on Valhall, this assignment was worth about NOK 345 million in 2004 value. The work involved installing four new pipelines, each 6.5 kilometres long, in 70 metres of water.

May 2007: PDO for Valhall redevelopment approved. This plan was submitted on 22 March 2007 and approved by the Council of State on 25 May.

In order to ensure safe and long-term operation, the licensees wanted to redevelop the field centre and extend its commercial life to 2049.

Three options were considered – modifying existing units and keeping them in operation, installing two new facilities for quarters and processing respectively, and building a new integrated platform to replace the older units. The last of these was recommended by the licensees.

2008: Valhall flank gas lift project. Work on this development began in the autumn with the aim of boosting oil production from the flank platforms.

Fabricated by Aker Solutions in Egersund, the necessary modules were installed in September 2009 and became operational in 2011.

February 2009: Valhall land-based control centre opened. The new Valhall production advanced collaboration environment (Pace) was opened at the BP building at Forus, helping to tie land and offshore closer together.

That provided such benefits as making production easier to optimise and simplifying planning, everyday logistics and operational support.

A new production control centre has also been installed at Forus. All wells on Valhall can be controlled and monitored both from land and offshore. This facility allows a number of experts to study real-time data and take decisions.

2011: Valhall PH process and hotel platform installed. Seabed subsidence and the need to operate more efficiently led to the construction a completely new installation for the field.

This facility provides 180 berths and is connected to the IP by a bridge. It gets all its power from shore via a 294-kilometre submarine cable from Lista. That eliminates virtually all carbon dioxide and nitrogen oxide emissions.

The producing life for Valhall is expected to extend to 2050.

26 January 2013: Valhall PH becomes operational. The Valhall centre thereby comprised six separate installations, for quarters, drilling, processing, wellheads, water injection and processing/hotel respectively.

In addition come two unstaffed flank platforms, both placed about six kilometres from the main cluster.

25 March 2013: gas exports start from Valhall PH. Gas began flowing from the new platform at 00.05.10. A long process had led up to this milestone, with good collaboration between everyone involved in the start-up team.

2 October 2013: PCP ceased operation. A good deal of work remained to be done after the power had been switch off on the Valhall PCP process and compression platform. Most related to disconnecting electrical and instrumentation systems from the rest of the field.

For some of the personnel, who had worked on the platform for many years, this was undoubtedly a sad day. The control room on the PCP had been a meeting place for many.