ARE YOU SEEKING SURETY IN DRILL RISER BUOYANCY DESIGN, MANUFACTURE AND DELIVERY?

Drill riser buoyancy provides uplift while reducing the submerged weight of the riser joints. This helps to minimise top tension and prevent stress in the riser as well as reducing loadings during deployment and retrieval of the blow-out preventer (BOP) stack.

Drilling risers extend from the BOP to the drilling vessel with their primary function being the provision of fluid communications between the well and the vessel while supporting choke, kill and auxiliary lines. Balmoral consistently manufactures high quality modules while its in-house hyperbaric test centre offers test facilities to 7000msw equivalent.

Balmoral drilling riser buoyancy modules are fitted around the riser with moulded apertures accommodating auxiliary lines and riser clamps.

The vertical lift of the syntactic modules is transferred to the riser by a thrust collar fitted to the riser pipe below the upper coupling. A matching collar is normally installed at the lower end of the assembly to facilitate the transfer of the module weight during handling.

Balmoral DURAFLOAT^® and
Balmoral DURAFLOAT RIS™ (Residual Integrity System)

The demands placed on drilling riser buoyancy have increased dramatically as the industry continues its exploration and development of ever deeper waters.

Similarly, the requirement for ultra-safe modules has grown in response to the extreme conditions which are now commonplace in today’s operating environments.

Balmoral’s design team was tasked with the development of a high performance ultra-safe riser buoyancy system to accommodate and perform in the most arduous of conditions. The team created a specialised riser buoyancy series, Balmoral DURAFLOAT RIS, comprising a high impact protective skin and residual integrity system.

Significantly, Balmoral DURAFLOAT RIS is designed to minimise the risk of cracking and fracture while delivering safe high performance uplift.

Buoyancy plays a critical role in the dynamic performance of the riser string and Balmoral DURAFLOAT RIS is an important step forward for the industry. Its contribution to safety and performance should not be underestimated.

Balmoral DURAFLOAT SUPERLITE™ and
Balmoral DURAFLOAT SUPERLITE-X™

Having successfully developed its DURAFLOAT drill riser buoyancy to working depths of 12000ft, Balmoral recognised that further performance improvements were required.

Basing their work on the original DURAFLOAT system, Balmoral’s technical and engineering teams developed a lighter syntactic material for use at operational extremes to 15000ft.

However, the essential increase in mechanical performance required to operate at these depths cannot be accompanied by a reduction in available buoyancy, and so foam density reduction was targeted alongside mechanical performance improvement.

The result of the R&D programme is Balmoral DURAFLOAT SUPERLITE and Balmoral DURAFLOAT SUPERLITE-X. With these latest additions, Balmoral now offers market-leading densities and performance levels across the entire spectrum of drilling operations.

All Balmoral DURAFLOAT and DURAFLOAT SUPERLITE modules feature a number of advanced performance-related benefits including:

• Extreme impact resistant shell
• Anti-fracture reinforcement
• Enhanced flexure resistance
• Improved stacking and storage capability
• Localised recess reinforcement

In simple terms, more uplift is provided for the cost when specifying Balmoral DURAFLOAT SUPERLITE and DURAFLOAT SUPERLITE-X.

More uplift for your money

This chart shows how much more uplift is provided by Balmoral DURAFLOAT SUPERLITE and DURAFLOAT SUPERLITE-X systems in comparison to industry standard systems.

Even at 7000ft there is approximately 10% improved uplift performance. When depths of 12000-15000ft are reached this increases by an outstanding 30-50% respectively.

External finishing

Drilling riser buoyancy operates in extreme conditions and must withstand harsh and constant handling. Balmoral DURAFLOAT modules benefit from an integral composite epoxy skin that delivers a robust impact resistant performance.

Attachment methods

Balmoral offers strapping with stainless steel axis bars and stud bolts as standard attachments between module and riser. Further options are available including through bolts located in reinforced pockets or stainless steel U-bolts with enclosed Kevlar strapping.

Dependent on riser geometry these options can be located within the pitch circle diameter (PCD) of the auxiliary lines thus reducing the transverse bending moment on the buoyancy module.

Module stability

300mm flats are standard across the DURAFLOAT range. This allows effective stacking in the yard and in the offshore operations environment.

A fully comprehensive handling and stacking manual is available from the company on request.

Flexural pads

Flexural pads are built into Balmoral buoyancy modules at strategic locations to ensure that excessive bending loads are not transferred from the riser to the module when lifted in the horizontal plane.

Module repair

Balmoral offers a comprehensive global repair service for damaged buoyancy modules that includes repair of full breaks and rebuilding of missing sections.

The company’s skilled buoyancy refurbishment technicians are available for field work at most locations worldwide.