Safeguarding a unique deep sea environment


Jørn Bo Larsen

Jørn Bo Larsen

Chief Consultant
T: +45 51618663

Environmental impact assessment (EIA) of offshore Statoil pipeline (Norwegian Sea Gas Infrastructure - NSGI).

The Norwegian Sea in places presents some unique challenges and features in connection with pipeline installations. At its deepest location, the pipeline will be situated 1.3 km below the surface. On its way to shore, the pipeline will be passing through rough, uneven seabed terrain with sensitive marine environments such as cold-water corals. 

Understanding of the local conditions 

Ramboll was seconded to Statoil in Stavanger as assistance in preparing a full Environmental Impact Assessment (EIA) of the pipeline system.

The NSGI EIA assesses environmental and societal impacts, based on a solid understanding of the local conditions. Interfaces to associated EIAs (e.g. Nyhamne, Aasta Hansteen) were managed to ensure a holistic approach.

Statoil's natural gas pipeline will be connecting the Aasta Hansteen gas field, just north of the Polar circle, and other future fields in the Norwegian Sea, with an onshore gas terminal at Nyhamna.  The operator, Gassco, will ensure further transportation of the gas to continental Europe and the UK. The water depth at Aasta Hansteen is 1.3 km, and 480 km 36" pipeline is routed to Nyhamna Gas Facility. A new export pipeline from the Kristin platform is also included as part of Ramboll's scope of work.

An approved EIA is a prerequisite for realisation of the NSGI project.

Assistance to the NSGI project

Ramboll was seconded to Statoil in Stavanger as assistance to the NSGI project. The main task was to prepare an Environmental Impact Assessment (EIA) of the pipeline system, and providing ad hoc assistance on HSE matters within the NSGI project.

Ramboll prepared a proposal for the NSGI EIA program which was sent for public consultation to 81 hearing parties, including municipalities, NGOs and government institutions.

Local conditions

Incorporating input from the public consultation and approval by OED, a full Environmental Impact Assessment was prepared. The EIA prepared by Ramboll takes into consideration the local conditions, applying Ramboll's international EIA experience in a Norwegian context.

The NSGI EIA assesses environmental and societal impacts, based on a solid understanding of the local environment. Areas of particular concern were cold-water corals, fish and fisheries and ship traffic. Through close communication with the technical team, the project was adjusted to minimize environmental impacts.

Impact assessments (EIA, ESIA) is used to identify and assess environmental and social effects, compare alternatives, and design mitigation measures. Ramboll has extensive experience with EIAs of offshore pipeline systems, with Nord Stream, SkanLed and Baltic pipeline as notable examples.

Ramboll Oil & Gas was awarded the contract for technical design (FEED) of the NSGI pipeline in August 2012.


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