1. Home
  2. News and insights
  3. Energy in focus magazine
  4. Fast-paced subsea tiebacks

Rising tieds

Release date:
18 December 2020
Reuse is central to bp’s subsea tieback projects. Here, we take a closer look at the principles of engineering involved. Plus, find out how adopting a new mindset has helped put rocket boosters on this tried and tested way of delivering energy
🕒 2.5 min read | 📖 Feature| 💡 Why it matters

The successful start-up of the R Cluster gas field in India is the latest in a line of projects using subsea tiebacks to deliver more competitive production – a key plank in our strategy to become an integrated energy company. 

But what exactly is a subsea tieback?

A subsea tieback is an engineering process that connects an oil or gas discovery to an existing production platform. The system usually includes a subsea wellhead, Christmas tree and a flowline that carries the hydrocarbons back to the facility. It might also involve other commonly used pieces of equipment, such as manifolds and additional pipelines, and may require a bit of modification on the platform. Think of it as the plumbing between the seabed and the production facility. 

Subsea infrastructure ready for load-out to the KG D6 offshore location in India

The oil and gas industry has been using subsea tiebacks for decades to help realize additional production value or unlock commercially complex reservoirs. 

“Tiebacks help us to reach out into pockets and areas of oil or gas that might otherwise remain undeveloped,” says Aasha Marenghi, a project performance lead for the North Sea and Angola. “And because we can connect them to existing facilities, we can reduce our capital expenditure, extend an asset’s life, help to retain jobs and keep our environmental footprint to a minimum.”

These benefits are important in a region like the North Sea. The Oil and Gas Technology Centre (OGTC) estimates that of the 3.4 billion barrels of hydrocarbons sitting in more than 360 marginal developments, some 2.5 billion barrels could be developed via subsea tiebacks. 

💡 Why it matters

Resilient and focused hydrocarbons will play a key role in fulfilling our new strategy as we transition from an international oil company to an integrated energy company. By making the most of our existing assets, we can access and deliver new barrels at low cost and in rapid time.

The control riser platform to which the KG D6 project is tied back

Umbilical load-out for KG D6

KG D6 pipeline in the seabed

But while the engineering isn’t novel, what has been new for bp is the fast-paced nature of their development, particularly in the North Sea, where bp’s teams and their partners have adopted a more agile approach to project development. This means “rather than taking four or five years of planning and development,” says Aasha, “we’re essentially developing them in one to two years.”


Working agilely means doing more things in parallel, more quickly, explains Marianne Wheeler, discipline manager for subsea project management. “Instead of having several major management approval stages, you have one final investment decision approval and then carry out appropriate self-verification checks along the way. Where you can put in some additional equipment and connect new wells to an asset that is already operating at good rates, your costs are that much lower, so your rate of return is that much higher. They are a very efficient, profitable way to develop new oil and gas resources.”


“Subsea tiebacks are a very efficient, profitable way to develop new oil and gas resources.”


Marianne Wheeler, discipline manager for subsea project management

Our subsea tiebacks at a glance

From the North Sea to the Gulf of Mexico and from Angola to India, whether in bp-operated or non-operated joint ventures, operational teams from around the world are delivering subsea tiebacks. Here are a handful of our most recent successes: 

R Cluster, India

  • Gas field brought onstream in December 2020. 
  • Six new wells are now connected via subsea tieback to the existing control riser platform off Block KGD6.
  • It is expected to produce up to 12.9 million cubic metres of gas a day.

Vorlich, North Sea

  • Brought onstream in November 2020.
  • Two new wells are now connected to Ithaca Energy’s FPF-1 floating production facility.
  • Peak production expected to reach 20,000 barrels of oil equivalent gross a day.

Alligin, North Sea 

  • Brought onstream in December 2019.
  • Two new wells are now connected to existing Schiehallion and Loyal subsea infrastructure and the Glen Lyon floating production, storage and offloading (FPSO) vessel.
  • Producing 15,000 barrels of oil equivalent gross a day.

Be the first to know...

Keep up to date with all the latest developments on our net zero journey by signing up to our monthly newsletter