The Dvalin gas field is being developed as a subsea tieback to the existing Heidrun platform. Image courtesy of Wintershall Dea.
The initial field development plan comprises a subsea template, four production wells, and related subsea infrastructure. Image courtesy of Øyvind Hagen/Equinor.
The Dvalin field, operated by Wintershall Dea, is expected to start production in the fourth quarter of 2020. Image courtesy of Wintershall Dea/John Iver Berg.

The Dvalin gas field being developed as a subsea tieback in the Norwegian Continental Shelf is all set to commence production in the fourth quarter of 2020. The Norwegian Petroleum Directorate granted consent for the start of operations at the offshore field in October 2020.

Wintershall Dea holds a 55% stake and is the operator of the field, while the other development partners are Petoro (35%) and Edison (10%).

The Dvalin field development plan involves subsea development and tieback to the Equinor-operated Heidrun platform in the Norwegian Sea.

The project partners submitted the plan for development and production (PDO) of the Dvalin field to the Norwegian authorities in October 2016 and received approval for the same in March 2017.

Location and reservoir details

The Dvalin gas field is located approximately 260km north of Kristiansund in the central part of the Norwegian Sea, Norway. The Heidrun field lies approximately 15km southeast of the Dvalin field, while the Skarv field is located approximately 35km north of the Dvalin field.

Situated in the Haltenbanken area of the Norwegian Sea, the water depth of the Dvalin field area is estimated to be approximately 400m.

The gas reservoirs of the Dvalin field are located approximately 4,500m underneath the sea bed and comprise the Middle Jurassic sandstone of the Ile and Garn Formations.

The recoverable resources at the field are estimated to be approximately 113 million barrels of oil equivalent (Mboe).

Dvalin gas field development plan

The Dvalin gas field development comprises a subsea template with four production wells with the template connected to the Heidrun platform by flowlines and umbilicals.

A new gas processing and compression module, weighing approximately 3,500t, was installed on the Heidrun platform to handle well stream from the Dvalin gas field, in August 2019.

Separately, a utility module, weighing approximately 577t, was installed on the existing offshore platform in 2018.

The Xmas trees, weighing about 52t, were installed in December 2019, while the drilling of the four high-pressure, high temperature (HPHT) production wells on the Dvalin field was completed in August 2020.

A 14.9km-long pipeline will export the gas produced at the Dvalin field to the Heidrun platform. A 7.5km-long pipeline transports gas from the Heidrun platform to the Polarled trunk line which delivers gas to the Nyhamna onshore gas terminal for further processing.

Wintershall Dea is responsible for subsea work on the Dvalin field, while Equinor took responsibility for the modification works at the Heidrun platform.

Contracts awarded

Aibel was awarded an engineering, procurement, construction, and installation (EPCI) contract worth approximately £292m ($376m) by Equinor to build two new modules for the Heidrun platform in October 2016.

The two modules installed on the Heidrun platform are a gas treatment and compression module, and a utility module. The Saipem 7000 lifting vessel was employed for the installation of both the modules on the Heidrun platform.

Aker Solutions was awarded two contracts worth at least £87.5m ($112.7m) by Wintershall Dea to deliver the subsea production system and provide maintenance services in October 2016.

The first contract was for a subsea production system comprising a manifold, four subsea trees, wellheads, control systems, and a 15km-long umbilical from the Heidrun platform to the Dvalin template.

Separately, a five-year framework contract was agreed upon for the maintenance and services of all subsea production systems ordered under the first contract. The scope of the contract included the installation and commissioning services.

Transocean Norway Operations received a contract worth approximately £51.5m ($68m) for drilling four production wells in the Dvalin field in November 2017. The Transocean Arctic drilling rig was deployed to execute production drilling works.