Installation Underway for World's Longest Heated Subsea Pipeline

Installation is underway in the Norwegian sector of the North Sea for the world’s longest heated subsea production pipeline, oil and gas company Neptune Energy has informed.

The project will see the installation of the 36-kilometer electrically trace-heated (ETH) pipe-in-pipe solution transport oil from the Neptune Energy-operated Fenja field to the Njord A platform, operated by Equinor.

The first phase of the installation saw a 9km section safely installed and successfully tested, the company said.

Neptune Energy’s Director of Projects and Engineering in Norway, Erik Oppedal, said: “The installation and testing of the ETH pipe is a great technical achievement, as well as a milestone in the development of the Fenja field. Norway is an important part of our geographically-diverse portfolio and this is an excellent example of Neptune Energy’s commitment to investing in the region and adopting advanced technologies to overcome challenges. The heated pipe-in-pipe solution permits us to tie the field back to existing infrastructure, keeping costs low.”

According to Neptune, the length of the ETH pipeline is a significant technological achievement and was developed and qualified through a collaborative approach with TechnipFMC. 

"Due to the high wax content of the Fenja field’s oil, the contents of the pipeline must be warmed up to a temperature above 28-degree Celsius before starting the flow after a shut down. During normal production, the temperature in the pipeline is well above this temperature," Neptune explained.

Ståle Ryggvik, TechnipFMC’s Project Director, added: “TechnipFMC is delighted that the extensive qualification program for the ETH Pipe-in-Pipe for Fenja has been successfully completed, and that the first section of the pipe has been installed on the seabed.

“This technology step change has been made possible by the extraordinary effort of TechnipFMC and excellent cooperation with Neptune Energy. It will unlock possibilities to develop future projects with difficult reservoir properties. We are looking forward to continuing the project and completing the installation in 2021.”

The offshore installation was carried out by TechnipFMC’s vessel, Deep Energy, approximately 120km north of Kristiansund, Norway, at a water depth of about 320m.