Aasgard B

Offshore drilling expeditions in harsh subsea regions and technologically challenging places are set to become easier, with the development of new subsea gas compression technology that will facilitate production of oil in a platform-free environment.

Royal Dutch Shell has deployed a prototype compressor at the Ormen Lange natural gas field in the Norwegian Sea, which is likely to make platform-free offshore production a reality within a decade.

The technology will be particularly beneficial in places such as the Arctic and Alaskan regions, where installation of rigs is an ecological and technological challenge. Norway’s Statoil has also committed to subsea compression at its Aasgard field by 2015.

The demand for such technology is expected to increase in the future as the International Energy Agency says that 45% of the 2,700 billion barrels of recoverable oil left is from offshore sources.

"The technology will be particularly beneficial in places such as the Arctic and Alaskan regions."

The agency predicted that deep-sea production will double to 8.7 million barrels a day by 2035, due to massive developments taking place in the US part of the Gulf of Mexico, Brazil and West Africa. Energy firms are compelled to move to deeper waters as the fuel reserves in shallow waters become depleted.

Compressors on the sea bed consume less electricity since they are close to the reservoir and the surrounding water already exerts immense pressure. Shell’s Ormen Lange, located 120km out to the sea, would be powered from the shore while Statoil’s unit will receive electricity from a nearby platform.

Aker Solutions subsea chief, Alan Brunnen, was quoted by Reuters as saying: "This means you’re squeezing out more, an extra five to ten percent, possibly more or less, depending on the specifics."

If the technology succeeds, oil and gas exploration companies operating in the Arctic will benefit hugely as the harsh environment makes production risky and politically sensitive.

According to the US Geological Survey, the Arctic holds 90 billion barrels of oil in reserves plus 47 trillion cubic metres of gas, reported Oil Price.com.

Statoil subsea chief Bjoern Kaare Viken told Reuters: "Subsea compression in the Arctic reduces the risk because you can operate under ice and you’re not dependent on operating the facility in a very difficult environment."

FMC Technologies and Siemens Industrial Turbomachinery are also working to develop a electrically-driven, centrifugal gas compressor that can operate in water depths of about 3,000m (about 9,842ft).

FMC said the application, which can operate for several years without maintenance, would be available to the market from 2011-2013.


Image: Aasgard field. Photo courtesy of Statoil.