The use of flexible pipe in offshore oil and gas production is usually grouped into two categories; static and dynamic. Dynamic applications normally involve an offshore floating production facility or terminal connected to another floating facility or fixed structure.
Flexible pipe and umbilicals require the use of buoyancy modules to reduce topside or tension loads or to achieve a particular configuration as illustrated below.
The Balmoral distributed buoyancy system generally consists of two parts; buoyancy and clamping system. The buoyancy elements are supplied in two halves incorporating a moulded-in recess. The edge of the recess is designed to transfer forces from the buoyancy modules to the clamp and thus to the riser.
Each clamping system is designed to suit project parameters such as loading and environmental conditions.
Product design, engineering and materials The densities and composition of distributed buoyancy modules are based on operational parameters such as hydrostatic pressure,uplift, water ingress, riser diameter, etc.
However, the main elements of the modules comprise microspheres and macrospheres encapsulated in a polymer syntactic foam matrix.
Operating what is probably the most advanced buoyancy manufacturing plant in the industry, Balmoral provides very high quality, void-free, consistent modules which result in low water absorption and compression throughout their service life.
In higher temperature applications the buoyancy modules incorporate convection channels.
Technical information
Attachment methods The buoyancy elements are fastened around the clamp and riser using two sets of securing straps, usually made from Kevlar. The straps are tensioned using cross bar and screw mechanisms and fitted into moulded-in recesses on the body of the buoyancy element.
Balmoral also offers a bolted fastening system. External finishing BOE provides finishing options of rotationally moulded polyethylene, polyurethane elastomer or glassfibre external skins which offer the following benefits:
• Abrasion and impact resistance
• Enhanced water ingress performance
• Marine growth resistance
• High-vis pigmentation
• Customised graphics option
