Low-pressure production on Ormen Lange
Ormen Lange is a mature gas field produced from a subsea system to a process facility on land at Nyhamna in Møre og Romsdal county. It was decided to implement gas compression from the field in two phases – on land and out on the field.
Compression facilities were installed on land in connection with the expansion of the gas processing plant at Nyhamna to handle the Aasta Hansteen/Polarled development, and became operational in the fourth quarter of 2017.
They aimed both to increase the recovery factor on Ormen Lange and to maintain capacity at the Nyhamna plant when gas from Polarled was introduced, independently of reservoir pressure in Ormen Lange. Compression on land increases the recovery factor from 67 to 75 per cent.
The licensees have opted for subsea compression on the field as phase two. This will reduce wellhead pressure more than land-based compression, and thereby improve recovery. The final choice of the subsea concept is expected later in 2019, followed by an investment decision. Subsea compression has the potential to increase the recovery factor to more than 80 per cent.
Figure 2.14 Ormen Lange. Illustration: AS Norske Shell.