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 Offshore Engineering’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, Durafloat RIS, comprising a high impact protective skin and residual integrity system. Significantly, 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 Durafloat RIS is an important step forward for the industry. Its contribution to safety and performance should not be underestimated.
External finishing
Drilling riser buoyancy operates in extreme conditions and must withstand harsh and constant handling. Durafloat modules incorporate an integral composite epoxy skin to deliver a robust impact resistant performance.
API 16F
Balmoral Durafloat RIS modules are designed, manufactured and type tested in full accordance with API 16F.
Durafloat RIS safety features
Attachment methods
Balmoral Offshore Engineering 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 environment.
Flexural pads
Flexural pads are built into BOE 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.
Colour coding
A colour system exists for quick identification of differing depth rated modules. A typical example of this is shown here:
