Nova risers installed

Wintershall Dea cheers fresh Nova milestone with most of subsea hardware now in place

German oil and gas company Wintershall Dea has completed another milestone for its operated Nova project, which is located offshore Norway, following the installation of the risers on the North Sea field.

Wintershall Dea's Nova field. Credit: Neptune Energy

The Nova subsea campaign kicked off last May with the installation of two manifolds in the templates on the seabed of the Nova field development.

The project will deliver hydrocarbons via two new subsea templates to the nearby Neptune Energy-operated Gjøa platform.

Wintershall Dea said in an update on Thursday that, following the installation, the risers are now ready to connect the underwater pipelines to the Gjøa platform.

The oil company also noted that most of the Nova subsea hardware is now in place.

The risers tie two production pipelines, as well as a water injection and a gas lift pipeline, to the specially constructed Nova module that was installed on the host platform Gjøa in May 2020.

Through the newly installed risers, Gjøa will provide injection water and lift gas to the Nova field and receive the hydrocarbon well stream.

With the field’s two underwater templates and manifolds in place, the pipeline systems installed and modifications to Gjøa well underway, Wintershall Dea now looks toward the start of the Nova drilling campaign.

A couple of years ago, Wintershall Dea hired the Seadrill-operated West Mira rig for the Nova drilling campaign.

Dennis L. Dickhausen, Wintershall Dea Nova Facilities Vice President, said: “The riser installation is a big milestone for the subsea part of the Nova development. It is the last piece of the puzzle in completing the subsea pipeline systems.

“With all the pipelines and risers now in place, we are nearing finalization of the Nova subsea scope. The next step will be to start drilling”.

National Oilwell Varco designed and fabricated the risers in Kalundborg, Denmark. They were picked up by Subsea 7’s Seven Arctic vessel which installed them on the Nova field, 120 kilometres northwest of Bergen.

After the summer, the risers will be tied-in to the pipelines, tested and finalized for commissioning and production start.

As part of the riser installation, the Gjøa platform was shut down for two weeks, allowing the new subsea hardware to be connected to the Nova topside module.

The operation was supported by Rosenberg Worley, which was also conducting other critical work on the Nova topside aboard Gjøa.

The installation was planned to coincide with a general shutdown of the St Fergus onshore terminal, to make it cost-effective.