Established in 1980, Balmoral has an enviable reputation across the world for product design, development and delivery.

With 500+ people based at our purpose-built 250,000ft2 facility in Aberdeen, we build successful relationships with clients working with them from concept development and advice through to product design, manufacture, testing, delivery and support.

All managed in-house to give total safety, quality and scheduling control.

Bend stiffener



Water depths, seabed conditions, high pressures and high temperatures are all factors to be considered when designing systems for the extraction of hydrocarbons in deep and ultra-deepwater fields.

Ultra-deepwater fields have attracted much attention in recent years and have generated a range of riser solutions to transport the produced hydrocarbon fluids to the surface processing facility. In some cases these solutions reflect the particular expertise of the main contractor while project-specific requirements dominate in other scenarios.

Established solutions include steel catenary risers, flexible flowlines in wave or MWA configuration, single leg top-tension risers and hybrid riser towers. The last-named refers to multiple risers grouped around a single core pipe where the entire assembly is supported in vertical orientation by a massive buoyancy assembly. Due to operational depths going to some 2000msw the majority of solutions require buoyancy to provide hydrodynamic stability and/or riser tension reduction.

With the particular field configurations, depths of reservoirs and relatively benign sea states found offshore West Africa, the hybrid riser tower (HRT) has assumed a dominant position. With the proven success of HRTs in four major West African projects to date the same solution offers significant potential for other deepwater projects both there and elsewhere in the world.

The hybrid riser tower typically comprises 4-12 individual risers grouped around a central core pipe anchored to the seabed and supported by a massive air can at the top. Further to this tower-top air can, buoyancy is routinely provided along the length of the bundle and on occasion at the upper and lower riser tower assemblies – URTA and LRTA respectively.

The primary purpose of the bundle, URTA and LRTA buoyancy systems is to facilitate surface tow-out of the bundle, however the same buoyancy also contributes to the stability of the vertical HRT when in service.

Balmoral riser tower buoyancy


Riser tower buoyancy modules

Due to the significant buoyancy requirement on the tower itself Balmoral developed a new processing plant to produce its largest ever drill riser buoyancy style module, coming in at some 2.2m in diameter, 5.2m long and providing 6500kg of buoyancy per module.

With additional factors such as anti-rotation and anti-slip requirements, Balmoral combined technologies from its patented distributed buoyancy integral clamping solution with a drill riser buoyancy style module and, due to the length and physical size of the module, a dual position installation tool was developed followed by an arduous qualification and testing programme.

Riser tower buoyancy modules

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Balmoral Comtec Ltd
Balmoral Park, Loirston, Aberdeen AB12 3GY | +44 (0)1224 859000 |
Registered number SC301819