Ormen Lange II on track

Ormen Lange operator Shell in Norway has confirmed plans to proceed with the subsea compression technology qualification programme it is undertaking for the second phase of the field’s development.

With three wells now on-stream at Ormen Lange from the A subsea template, and plans to bring two more wells online towards the end of this year, Norske Shell, which took over as Ormen Lange operator from StatoilHydro last year, says it is willing to pursue a twin-track approach to the second phase of Ormen Lange.

This involves qualifying subsea compression technology for phase two while also retaining the option to use a deepwater floating platform instead if desired to provide reservoir pressure boosting.

When the plan for development and operation of the field was approved in 2003, it was based on field reserves of 400 Bcm, making Ormen Lange the second largest gas field offshore Norway after Troll.

“Twenty-five per cent of the reserves that Norway expects from this field need to be compressed offshore or need to be helped to shore, and that was understood at the time of the PDO,” said Bernt Granas, project manager for Norske Shell responsible for Ormen Lange phase II.

Explaining the reasoning behind the twin-track approach, Granas said: “The prime solution is still a deepwater floater, and we are in the concept studies at the moment.”

And he also confirmed the development of the alternative subsea compression solution now underway by field partner StatoilHydro, based on a quarter of the size of a full subsea processing station.

Component testing will take place for two years from 2010, in a test pit at the Ormen Lange onshore gas plant at Nyhamna. “There can be various solutions to this,” said Granas. “We are not going to a make a decision about this next year or the year after. We have to be open to both solutions or a combination of the two.”

Ormen Lange lies offshore in water depths ranging from 850 to 1100 m (2,800 – 3,600 ft) with very rough sea conditions, and the subsea option represents a potential for saving approximately 20% of second phase development costs compared with a surface facility providing gas compression.

As part of the pursuit of the subsea compression development, 57 technical qualification programmes are underway. Compressors have been ordered as well as variable speed drives too, Shell’s Granas said.

Images shown by Norske Shell suggest a subsea compression module could bet 25 m high, 54 wide and 70 m long, (82 ft by 177 ft by 230 ft) and would weigh around 5,400 tons.

Commenting on the cost-saving that the subsea solution offers, Ganas said it is not substantial. “It could be 20% cheaper than the floater,” he said. “It is not a huge value thing, it is a technical thing. which we think could be a huge advantage.”

But even the floating production solution – if used – would be different from conventional floating platforms seen today, he indicated. “I think the floater will be very different from something you are putting into a field today,” he commented.

Costs for phase two development of Ormen Lange are put at around NOK 38 Bn, (US $7.07 Bn) including subsea compression, which is in addition to the 51 Bn ($9.49 Bn) budget for phase one.