Improving recovery with subsea facility

This technology is a breakthrough for a new generation of subsea solutions in the oil industry. The Tordis subsea development is part of a project which will improve the recovery factor for the Tordis field from 49% to 55%. This amounts to roughly 35 million barrels of oil, in addition to associated gas.

The full potential of the subsea facility has not yet been realised, due to unforeseen challenges with the injection well, but alternative solutions are currently being evaluated.

Opening up new possibilities
"The technology we have installed at Tordis opens up new opportunities for other fields operated by StatoilHydro, both in Norway and internationally," says Arne Sigve Nylund, senior vice president for operations west in Exploration & Production Norway.

Seabed separation makes it possible to improve recovery and accelerate oil and gas production. This increases the utilisation of installed facilities which has happened on Gullfaks C.

The technology provides added recovery of oil in cases where production is limited by pressure and capacity at the processing plants. The technology is particularly suitable in developments at great depths or far from shore and in areas where natural conditions and weather make subsea developments most appropriate.

Sending water back to the sub-surface
While it is usual to send the wellstream up to the platform where oil, water and gas are separated from each other in a processing facility, the new Tordis subsea separator removes water and sand before the oil and gas are pumped to the Gullfaks C platform.

The separated water and sand are pumped down into the Utsira formation directly from the subsea installation and stored there.

This solution means that large amounts of water from the reservoir avoid the 10-kilometre journey to Gullfaks C at sea level. This is an energy saver. It also reduces the discharge of produced water to the sea.

Seeing opportunities
StatoilHydro is one of the leading companies in the deep-water Gulf of Mexico and experiences from Tordis can help to improve development solutions there.

The knowledge gained from Tordis can also be useful for StatoilHydro in the Shtokman development in Russia. This technology can be used in many parts of the world.

FMC Technologies has designed and delivered the subsea facilities where the pump system from Framo Engineering is installed, whereas Grenland Group has been responsible for the fabrication. The installation work at the field was carried out by Acergy, Saipem and Fabricom.

Tordis - PL089 - lies in block 34/7, it is part of the Snorre business unit and came on stream in 1994.