DeepOcean completes subsea tie-back construction for Teal West development

DeepOcean has finalized subsea construction and tie-in activities at the Teal West development in the Central North Sea on the UK Continental Shelf for Anasuria Operating Company. The project connects the Teal West offshore oil and gas field back to the operational Anasuria Floating Production, Storage, and Offloading (FPSO) vessel.

Subsea Infrastructure and Tieback Installation
DeepOcean's scope encompassed the installation of a flexible production riser, a subsea flowline, and an electro-hydraulic control umbilical linking the Anasuria FPSO directly to the Teal West subsea Christmas tree. The contract also included protective seabed works along the flowline and umbilical corridors, followed by full commissioning of the newly installed subsea architecture.

Project engineering and management were coordinated by DeepOcean's Aberdeen office. Offshore execution followed a phased operational sequence, utilizing a subsea construction vessel for pipelay and connection tasks, followed by commissioning support from a second chartered construction vessel.

Diverless Robotics and Connection Tooling
Operations were completed using work-class remotely operated vehicles (ROVs) equipped with specialized subsea tooling, eliminating human diver intervention for pipeline integration. DeepOcean utilized its proprietary tie-in tooling to complete diverless mechanical connections across high-pressure subsea flanges, interfacing pipelines and subsea valves via robotic systems.

The Teal West field layout is designed for two production wells and one water injection well. Initial production connects a single well to the Anasuria FPSO via approximately three kilometers of subsea flowline infrastructure. The Anasuria FPSO is positioned approximately 180 kilometers east of Aberdeen in water depths of approximately 90 meters.

Additional Context
This section details technical specifications not included in the original news release.

Subsea tieback architectures in the Central North Sea utilize unbonded flexible pipes designed to withstand dynamic wave fatigue and cyclic internal pressures. Flexible flowlines and dynamic risers consist of layered structures combining an internal thermoplastic fluid barrier, helically wound carbon steel carcass layers for collapse resistance, and spiral-wound tensile armor wires embedded beneath an external polymer outer sheath to prevent seawater ingress. Electro-hydraulic control umbilicals integrate high-pressure stainless steel tubes for hydraulic fluid and chemical delivery alongside low-voltage signal cables wrapped within synthetic strength members to control subsea tree valves.

Diverless flange tie-in tooling systems operate from high-payload work-class ROVs equipped with specialized hydraulic positioning skids and torque tools. The tooling aligns misaligned pipe hubs on the seabed, draws flange faces into close axial contact using hydraulic pull-in cylinders, and actuates multi-stud tensioning rings to compress metallic ring-type joint (RTJ) gaskets evenly to precise torque specifications without diver entry into the water column. Trenching and seabed burial protect shallow-water flowlines from hydrodynamic scour and commercial fishing trawl gear through the use of subsea mechanical jet trenchers and post-lay rock-dumping mattresses.

Edited by Romila DSilva, Induportals Editor, with AI assistance.