Scattered across the North Sea like broken strands of pearls stand drilling and production platforms that have served for more than 40 years as visual clues to the hydrocarbon treasures that lie beneath the Norwegian Continental Shelf (NCS).

With the installation of the topsides that departed Kvaerner’s Stord yard in May, ConocoPhillips Skandinavia AS and its project partners—Eni Norge AS, Petoro AS, Statoil Petroleum AS and Total E&P Norge AS—will add another pearl to the Eldfisk strand.

Eldfisk at a glance

Discovered in 1970 and in production since 1979, the Eldfisk Field is located about 300 km (186 miles) offshore in the southern Norwegian North Sea. It is a part of the Greater Ekofisk Area (GEA). Water depths for the area range from 70 m to 75 m (230 ft to 246 ft). It is the second-largest of four producing fields in the GEA and one of the largest on the NCS, according to ConocoPhillips.

The field—according to the Norwegian Petroleum Directorate (NPD)—produces from the Ekofisk, Hod and Tor formations from the early Paleocene and late Cretaceous ages. The fine-grained and dense reservoir rock has a high porosity and can be found in depths ranging from 2,700 m to 2,900 m (8,858 ft to 9,514 ft). The field consists of three structures: Alpha, Bravo and Øst Eldfisk.

The original development plan for the field was approved in 1975 and consisted of three facilities: Eldfisk A, B and FTP. A and B are combined drilling, wellhead and processing facilities. The FTP is a wellhead and processing facility connected by a bridge to A. The Eldfisk E facility, installed in 1999, supports water injection efforts in the field as well as in the Ekofisk Field where water is transported via pipeline to Ekofisk K.

The FTP also receives production from the Embla Field. Discovered in 1988 and online in 1993, the Embla Field was developed with an unmanned wellhead facility remotely controlled from Eldfisk. Oil is produced from a complex segmented sandstone reservoir located at a depth of 4,000 m (13,123 ft), according to the NPD. Embla was the first HP/HT field to be developed in the area.

Eldfisk II project

On June 9, 2011—the 40th anniversary to the day that oil production first began from the Ekofisk Field—the Norwegian parliament or Storting approved the development and operations plans for the Ekofisk South and Eldfisk II projects.

The goal of the Eldfisk II project is to increase the oil recovery rate by approximately 6.5% to an expected recovery rate of 28.5% by the end of 2028. It is estimated that the project will see an increase in production of 220 MMboe to 283 MMboe from the field. In addition, ConocoPhillips stated in a release that the Eldfisk II represents total partner investments of $5.8 billion to $6.7 billion.

The ambitious Eldfisk II project plans called for the:

  • Installation of a new integrated platform—the Eldfisk 2/7 S—containing a wellhead, process and accommodation module with 154 single-bed cabins;
  • Installation of a bridge to Eldfisk 2/7 E;
  • Drilling of 40 new wells for production and water injection;
  • Conversion of Eldfisk 2/7 A to a wellhead platform and conversion of Eldfisk 2/7 FTP to a bridge support;
  • Modification of main systems on Eldfisk 2/7 B;
  • Installation of new hydrocarbon transport pipelines and a tie-in pipeline from the Embla field; and
  • Installation of power and fiber-optic cable for transmission of up to 20 MW between the Eldfisk 2/4 Z and Eldfisk 2/4 S platforms.

International construction project

Construction of the various Eldfisk II components occurred in several locations scattered across Europe. Topsides construction began in 2012, with first steel being cut in February of that year at Kvaerner’s Stord shipyard. Kvaerner’s subcontractors in Gdynia and Gda?sk—Vistal and Energomontaz-Polnac in Gdynia and Mostotal Pomorse in Gda?sk—started fabrication and construction of components in 2012. According to Mostotal Pomorse, its work on the project included installation grillage, pipe supports, electro attachments, cable transits and surface protection of all structural assemblies. The 154-cabin accommodation module was fabricated by STX Finland.

Subsea 7 is managing the subsea and pipeline elements of the project, including:

  • Fabrication, installation and tie-in of 24-in. oil and 30-in. gas Wye structures downstream of the Eldfisk 2/7 B platform;
  • Installation and tie-in of 24-in. oil export pipeline P2016S going from the Eldfisk 2/7 riser to the Wye structure downstream of the Eldfisk 2/7B platform;
  • Installation and tie-in of 30-in. gas export pipeline P2018S going from the Eldfisk 2/7 riser to the Wye structure downstream of the Eldfisk 2/7B platform; and
  • Subsea rerouting of the Embla pipeline P2040 to the Eldfisk 2/7 S platform.

The Eldfisk 2/7 S platform jacket was built at the Dragados shipyard in Cadiz, Spain, and was shipped directly to the Eldfisk Field.

Field prep, next steps

In April and May of 2013, the Saipem 7000 heavy lifting vessel conducted lifting work at the field. Included in this work was the installation on May 6 of the 96-m (315-ft) high and 13,000-mt (14,330-ton) jacket, according to the ConocoPhillips release. Due to its size, the jacket was skid-launched from the barge before being lifted and then placed into its final position. Other projects completed in 2013 included installation of the bridge linking the jacket to the Eldfisk Complex, the drilling template to allow predrilling through the 2/7 S jacket and a new waste heat recycling unit built in Stavanger’s Rosenberg yard.

The Maersk Innovator—one of two ultraharsh environment jackup drilling rigs in Maersk’s fleet—is set to start drilling the new production wells. According to ConocoPhillips, a total of 35 new wells will be drilled over the next few years. Four production wells and one well for reinjection of drill cuttings was predrilled by the Maersk Gallant.

First oil and gas from the new facilities is expected in 2015 with a capacity 70 Mboe/d estimated, according to a Total release.

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