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

Operating what is thought to be the most advanced buoyancy manufacturing plant in the industry, Balmoral provides high quality, consistent modules which result in low water absorption and compression throughout deployment and service. Balmoral distributed buoyancy modules are fully accredited by Bureau Veritas to API 17L standards.

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 and assist in achieving particular configurations which include steep, lazy, W-wave and pliant.

Balmoral distributed buoyancy modules generally consist of an internal clamping system and syntactic foam buoyancy elements. The buoyancy elements are supplied in two halves incorporating a moulded internal recess that is configured to transfer the forces from the buoyancy to the clamp and subsequently the flexible. This recess also accommodates bending of the riser during deployment and service. The internal clamping system is fixed to the pipe and the two half modules are fastened around the clamp.

Deepwater projects require modules and clamps to be designed specifically for operating at depths in excess of 3000msw where substantially larger modules and extreme clamping loads are demanded.

Balmoral has been at the forefront of significant R&D efforts to meet this challenge and has developed a number of solutions for deep and ultra-deepwater environments.

The densities and composition of the modules are based on operational requirements tailored to clients’ project requirements such as hydrostatic pressure, uplift, water ingress, flexible diameter, length, etc. However, the main elements of the modules comprise of microspheres and macrospheres encapsulated in a polymer syntactic foam matrix.

For high temperature applications, the foam composition is tailored to accommodate the effects of high ambient and line temperatures ensuring the design is fit for purpose in any condition.

Balmoral’s largest distributed buoyancy module to date provided 5.65Te uplift and was in excess of 3m long by 2m diameter. The modules were supplied with high performance clamps.

External finishing

• Abrasion and impact resistance
• Marine growth resistance
• High-visibility pigmentation
• Customised graphics option

Balmoral has listened to feedback from customers and developed a range of modular based products which maximise uplift and maintain the same design ethos of its buoyancy systems. Working with standard clamping systems Balmoral provides a range of incremental buoyancy modules using standard foam systems from 0-3000msw.

These ready made solutions provide cost effective options and are always considered where time and budget constraints are of utmost importance.

Balmoral’s buoyancy range generally uses symmetrical buoyancy modules sharing the same axis as the flexible or SCR. When this is not possible, due to the deployment method over a stinger/roller, Balmoral developed a piggyback clamped buoyancy design for use on steel catenary risers. This prevents the buoyancy module enduring excessive compressive loads as result of the weight and tension loads applied by the riser during deployment.

As oil and gas fields venture into new frontiers and ever deeper waters and steel catenary risers are used to transport hydrocarbons to the surface there will always be a need to control riser tension, reduce weight and control the shape of the catenary on the rise. This is traditionally done using distributed buoyancy, especially in the ultra-deepwaters of South America, Gulf of Mexico and Africa.

When using cylindrical pipes with traditional buoyancy in deepwater systems, VIV can be a catastrophic issue. Traditional distributed buoyancy modules typically use internal clamps that can potentially spin round the axis of the clamp which is unsuitable for VIV shedding as a continuous helix would be impossible to achieve.

Benefitting from its vast subsea experience, Balmoral designed a product to reduce excess weight and mitigate the effects of VIV on the riser. When combined with the company’s patented integral clamping device and installation methods this unique solution sets the company apart in the market place.

Balmoral also offers rotomoulded PE shells with retro fitted PU fins, or a more integrated system where the strake fin is cast into the outer coating of the module, both of which benefit from patent protected installation methods. It is essential that the stiffness of the PU fin does not endure permanent deformation while being deployed over a stinger roller.

Extensive testing and qualification demonstrated that the fin recovered its original shape as it left the roller meaning the VIV performance is maintained as designed. Additionally, the compressive loads applied by the risers and roller boxes on the modules required an extended testing regime to simulate the bending loads during deployment to ensure catastrophic failure of the modules would not occur.

Load transfer shims from the module into the riser were developed to ensure the bending loads were minimised and supported during deployment.

A major drawback to traditional strakes is increased drag relating to the fin diameter. Balmoral was inspired by nature, and the sea turtle in particular, to develop a low drag VIV suppression system that, combined with the company’s patent protected integral clamp system, provides an alternative to traditional strake systems.

Following a significant R&D programme, investment and comprehensive tank testing Balmoral designed an innovative solution that provides VIV shedding efficiency with a comparative significant reduction in drag.

• Patented Installation method for the integral clamp which is quick and effective
• Patented installation method is compatible with automated installation systems
• Build on Balmoral’s market leading reputation as a solution provider in the DBM market
• PU coatings provide added impact and abrasion protection