Visualisation platform N05-A and connection to wind farm Riffgat. (Credit: ONE-Dyas)
The proposed N05-A platform will be located about 20km from Rottumerplaat, Schiermonnikoog and the Borkum islands in the North Sea (Credit: Zachary Theodore on Unsplash)
First natural gas from N05-A is expected to be achieved in 2024. (Credit: NAC/

N05-A is an offshore gas field development in the Dutch North Sea. The proposed N05-A platform will be located about 20km from Rottumerplaat, Schiermonnikoog and the Borkum islands in the North Sea.

Dutch privately-owned exploration and production company ONE-Dyas discovered N05-A in 2017. Discover Exploration-subsidiary Hansa Hydrocarbons and Dutch-government-owned Energie Beheer Nederland (EBN) are the other partners of the project.

The field and its surrounding prospects are expected to produce 4.5 to 13 billion normal cubic metres (Nm3) of gas.

First natural gas from N05-A is expected to be achieved in 2024. The future production from the field will be aligned with the small gas field policy of the Dutch government.

Location details

ONE-Dyas and its partners EBN and Hansa Hydrocarbons are exploring gas production opportunities in an area in the North Sea called ‘Gateway to the Ems’ (GEMS). The region is located around 20km to 100km north of the mouth of the river Ems.

The N05-A gas field development is part of the initiative.

The offshore platform is in the offshore Netherlands, around 1.5km from German waters. The water is nearly 25m deep at the site, while the gas reserves are situated 4km deep in the subsurface in the Slochteren sandstone formation.

The estimated potential of the wider Dutch-German GES field is around 50 billion Nm3 in total, subject to successful exploration.

N05-A project background

The N05-A field was discovered in 2017 by drilling the N05-01 well in block N05-A.

Test drilling has also been carried out in prospects N05-A Noord, N05-A Sudost, Tanzaniet-Oost, and Diamant.

In 2018, the stakeholders began consultations for the development of the field. The engagement supported the development of the environmental impact report.

On 18 February 2022, the Commission for Environmental Impact Assessment issued final advice on the Environmental Impact Report (EIR) for gas production at N05-A. The EIR also addressed the usefulness and necessity of the project.

Following the advice of the commission and discussions with JV partners, the location of the N05-A production and drilling platform was decided to be shifted approximately 850m to the south.

The new location’s seabed mainly comprises sand and will have a less negative impact on the environment.

On 3 June 2022, the Netherlands’ Ministry of Economic Affairs and Climate (EZK) awarded the final permits for the development of the N05-A gas field and surrounding prospects.

ONE-Dyas, together with its JV partners, took the final investment decision (FID) for the development of the field in the North Sea in September 2022.

The project will involve an investment of more than €500m, the largest investment made in a natural gas development in the Netherlands in 15 years.


N05-A project development will include an unmanned production platform installed at the site. The platform will be around 50m above the water surface, comparable to the height of passing ships.

A number of wells will be drilled from a temporary drilling platform to produce gas, which will be transported to land using a natural gas pipeline.

The project will also extract gas from surrounding prospects, subject to potentiality.

ONE-Dyas expects offshore development to have a production life of ten to 35 years, depending on the underground uncertainties.

After the completion of the project life, the wells will be closed and the platform and pipelines will be decommissioned.

Environmental impact mitigation measures

ONE-Dyas has also planned to transport the drilling cuttings and drilling mud by ship and processed or dumped, instead of discharging it into the sea. This is expected to prevent the possible suffocation of soil life.

An active carbon filter will be used to purify the production water before it is released.

Additionally, the company will implement steps to limit nitrogen emissions during the construction phase and operation phases.

To minimise the nitrogen emissions during the pre-drilling phase (year 1), the flue gases from the diesel generators of the drilling platform will be treated with Selective Catalytic Reduction (SCR).

In the operational phase, the platform will run on renewable electricity supplied by the German wind farm Riffgat.

According to GEMS, the N05-A platform will be the first Dutch offshore gas treatment platform in the North Sea to run entirely on wind energy.

The electricity will be supplied through a cable from the 113.4MW Riffgat offshore wind farm located 15km northwest of the German island of Borkum.

The Riffgat offshore wind farm is equipped with 30 SWT-3.6-120 turbines manufactured by Siemens.