Bundles and towed installation

Bundles and towed installation

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FLOW-LAY

ƒ Surface tow ƒ Flowline slung below buoyancy ƒ Reusable HDPE pipe as carrier ƒ Installed by

Fabric strap with quick release

Reusable HDPE carrier

controlled flooding of line

ƒ Carrier straps released

Coated flowline

The system is similar in some respects to ‘flat-pack’ bundles in that the buoyancy is located above the flowline. However, with Land and Marine’s Flow-Lay system, the bundle is towed at the surface and the carrier is recoverable for reuse.

FLOW-LAYINSTALLATION

FLOW-LAY INSTALLATION

Touchdown position controlled using tension of tow tug

Flowline filled from surface through towhead valving

Touchdown monitoring

Flooded portion of flowline

Buoyancy floats to surface and is recovered in sections

Straps released

A pig is used to ensure that the flooding can take place in a controlled manner. The important difference in Flow-Lay is that with modern methods of touchdown survey monitoring, the flowline can be positioned exactly when combined with real-time control of the flooding and tow tug positions. All three vessels are in direct communication with each other. The tow tug can be moved either port or starboard to correct any lateral current on the pipeline.