INNOVATION EDGE™: FLOW-LAY® SYSTEM
The Flow-Lay® system, developed by Land & Marine, enables tugs to surface tow and install offshore pipelines and flowlines, leading to significant savings in cost, time and carbon emissions.
Description
Developed by Land & Marine Engineering Ltd, a wholly-owned subsidiary of Murphy, Flow-Lay® is a proprietary surface tow and flood technique for offshore pipeline installation. Designed to reduce costs and to provide an economical alternative to conventional methods, this allows pipelines to be fabricated on land, launched and towed to location in a single length.
A polyethylene (PE) pipe, attached to the steel pipeline or bundle, acts as a carrier, providing buoyancy and allowing the pipeline to be towed on the surface. Tow and trail tugs maintain tension in the pipeline during the tow and installation, decreasing the effect of wave action and reducing stress effects.
When aligned over the target, controlled flooding is initiated to release the pipeline to the seabed. Alignment along the route is maintained by adjusting the position of the trail tug as the deployment progresses. The process is reversible so that small adjustments can easily be made if necessary.
Once the pipeline has been laid on the seabed the carrier pipe is flooded and released by divers. Due to its natural buoyancy, the PE pipe will gently rise to the surface, where it can be recovered for re-use.
Benefits
- Can be used close to areas without direct water access from land, as the pipeline can be built remotely and surface-towed into place.
- Eliminates the requirement for specialist vessels which significantly reduces project costs, duration and carbon emissions.
- This method provides flexibility in route selection and is suitable for shallow water and beach crossings saving installation time and costs.
- Improved safety because the control and flooding of the system can be managed from the surface.
- Enables timely marine installation, reducing disruption to shipping lanes and port access.
- Allows the flexibility to lay rigid flowlines and pipelines including concrete-coated and insulated steel pipelines.
- Saves up to 85% on carbon emission by using local tugs rather than large specialist pipe-lay vessels.
