Benefiting from subsea technology

The Garn West and Rogn South producers would add some 81 million barrels (13 million standard cubic metres) or nine per cent to Draugen’s recoverable oil reserves as then calculated.

Shell’s decision reflected the fact that the technology for tying subsea wells back to fixed or floating surface installations had advanced by leaps and bounds during the 1990s.

Discoveries which had previously been too small to justify their own platform could now be developed instead with relatively cheap standardised seabed facilities.

These could be tied back to a fixed processing platform, a floating production facility or even to a processing plant based on land.

Advances with multiphase flow technology made it possible to send unprocessed wellstreams through pipelines over ever-longer distances.

Developing small satellite fields had become a profitable business, which was very welcome for the oil companies around 2000 when crude prices fell towards USD 10 per barrel. Subsea wells could also be installed and brought on stream quickly.

Garn West, on the westernmost flank of the Draugen area, was the first to be developed. Two subsea wells were tied back to the platform by 3.3-kilometre flexible flow line.

The NOK 130 million contract for the subsea part of this project was awarded on 31 May 2000 to Kværner Oilfield Products AS at Lysaker outside Oslo.[REMOVE]Fotnote: NTBtekst. 06.06.2000, «Draugen utvides for 130 millioner kroner». Installation was completed in July 2001.[REMOVE]Fotnote: Adresseavisen, 05.02.2001, «Draugen leverer olje helt til 2016».

The Rogn South development was approved in the spring of 2001 as the last drainage wells planned for Draugen.[REMOVE]Fotnote: NTBtekst. 06.06.2000, «Draugen utvides for 130 millioner kroner».

Kværner Oilfield Products had an option to deliver to this project as well.

Drilling rig Transocean Winner drilled and completed the two subsea wells in 2002, and the satellite came on stream in January 2003. The flowline carrying its wellstream runs to Garn West.

These two developments helped to increase and extend oil production from Draugen – which proved beneficial when crude prices began to recover seriously after 2002.

Shell invested a total of NOK 1.5 billion in these projects, and Kværner was not the only company to benefit from this spending.

Kristiansund also did well out of it, with the biggest local suppliers – Aker Møre Montasje and Vestbase – securing contracts in the order of NOK 70-90 million. Coflexip Stena Offshore landed the job of installing the flowlines, while the new water treatment system on the Draugen platform was supplied by Aker Offshore Partner at Stord.