Detailed design of a subsea tie-back
Our client was developing a prospect adjacent to one of their existing Southern North Sea gas fields. The field development involved a new subsea tieback to the existing platform via a 9 km long 8” pipeline and piggybacked umbilical.
Our client asked us to complete the detailed design of the new subsea tieback.
After completing the initial FEED design, we designed a rigid 8” trenched pipeline solution tied-in with two rigid expansion spools to an existing platform riser. The pipeline was piggybacked with a 110mm wellhead control umbilical and we ensured the design was optimised for a two-phased installation process. We also simultaneously carried out and integrated a sister detailed design project for the umbilical J-tube, allowing for integrated fabrication and installation.
Tackling the brownfield challenges of tieing into existing equipment, we verified the condition of existing assets and designed the interfaces to facilitate compatibility.
We carried out a full suite of pipeline mechanical design for process, strength and fatigue including pipe sizing, routing, stability, buckling, corrosion protection, _ ow assurance, crossings, bottom roughness, protection, specifications and commissioning procedures.
Throughout the project we conducted constructability reviews and installation support, working closely with the client, fabricators, installation contractors and regulators.
Our responsive service, with a dedicated lead engineer on the project, ensured all issues were resolved quickly and the design package elements were consistently ahead of schedule. Furthermore, our advanced expertise allowed in-depth consideration of interfaces and practical brownfield issues, to ensure risks associated with the fabrication and installation were identified early.
Our client benefitted from our seamlessly integrated services, from FEED to detailed design and through to construction support.