New purification technology lowers discharges on Troll

May 7, 2004, 10:00 CEST

New technology used on Hydro's installations reaped praise at this year's Offshore Technology Conference (OTC) in Houston.

Troll B and C have been at the forefront with several innovative water-purification systems in recent years. Efforts to develop new and even better purification technology continue with a view to achieving zero discharges of environmentally harmful substances.

The Troll C platform was the first in the world to install Epcon purification units on a large scale and VIEC water separators in the process plant. This equipment has helped to reduce considerably the amount of oil in discharged produced water, and was awarded the “spotlight on new technology” prize at this year’s OTC conference.

The Troll field has more than 100 production wells that recover around 370,000 barrels of oil a day. Extracting oil from the thin layers of Troll is challenging, and involves production of a great deal of water. This needs to be purified and there is a constant look-out for new technology that can further increase the level of purification. Contractors work closely with Hydro to develop new and better purification methods.

“Hydro has for many years played a key role in our technology programme, also in connection with the development of VIEC,” says Mikkel Martens, head of process technology in ABB Offshore Systems.

“Customer involvement has been important for ABB Offshore Systems, which specializes in process technology. It’s not just financing that’s important but also the confirmation that there’s a real need for the end product. Most important, however, is that the operator is willing to test the prototypes in a real operative environment. Hydro has shown such courage: first with Troll Pilot, and now with the application of VIEC on Troll C.”

Hydro’s action plan for achieving zero environmentally harmful discharges has a cost frame of NOK 430 million and will reduce discharges up to 80 percent.


  • Hydro and the other operator companies on the Norwegian continental shelf are required to reduce discharges of oil and chemicals in produced water with a view to achieving zero discharges of environmentally harmful substances by January 2006.
  • The tighter specifications for purification measures are a result of collaboration between the Norwegian Pollution Control Authority, the Norwegian Petroleum Directorate and the  Norwegian Oil Industry Association.
  • Hydro intends to achieve this target primarily through purification measures on Troll and reinjection of produced water on Oseberg.