The trend towards deeper and hotter drilling conditions have prompted the need for flowline insulation technologies with reduced heat transfer and increased mechanical strength.
To meet these needs, there are three methods of flowline insulation in deepwater operations:
1. Flexible insulated pipe
Flexible pipe insulation involves wrapped syntactic tape layers. This tape is made up of an extruded polypropylene thermoplastic combined with glass microspheres, and allows pipes to withstand depths of up to 9,842 feet (3,000 meters).
Flexible flowlines are often cost effective due to the fact that more direct flowline routing and simple installation compensates for the high cost of the complex pipe composition.
They're more than just cost efficient, however.
Flexible flowlines also offer installation efficiencies because installation and reeling operations are easier to manage than rigid pipe, and extended segment lengths are possible.
They can also have a lower hang-off angle, which allows for a more compact seabed footprint. Flexible pipe may also be recovered for decommissioning or reuse.
2. Pipe-in-pipe
The insulation in pipe-in-pipe flowlines is isolated from any damages that may occur during placement and handling, requiring a low strength and high insulating material to be used.
Its heavier weight may cause its use to vary, depending on the availability of the necessary installation equipment. Pipe-in-pipe construction and placement costs are generally more expensive than direct insulated flowlines.
While its cool down time may be shorter than direct insulated flowline, pipe-in-pipe insulation can achieve high insulation performance and low u-values.
3. Direct insulated pipe
Direct insulated pipes, also known as wet insulated pipes, are the most common type of insulation used in deepwater flowlines.
They are lighter than pipe-in-pipe flowlines and are applied by coating steel pipes with syntactic foam and placing them on the seabed–often without any cover or external protection. The hollow, low-density microspheres in this foam make it lighter and reduce the thermal conductivity of the pipe coating.
Each of these methods has its own advantages and disadvantages that should be considered when selecting the best option for a particular project. At Mark Tool, we’ve created the latest and greatest in subsea thermal insulation: ThermoTRON®.
This elastomeric, high-temperature thermal insulation system is key to protecting your pipelines from hot, deep, abrasive waters, as well as the splash zone. Contact us today to request a quote!