BUOYANCY - Offset installation buoyancy24 Jan 2021
Offset Installation Buoyancy
2015 - 2017
The offset installation equipment includes a carrier with adjustable buoyancy provided by ballast tanks and 200 tonne of buoyancy (manufactured by Matrix Composites and Engineering). Positioning is controlled through mooring and pennant lines. It can be used to install or remove capping, containment or related equipment in water, without direct vertical access. It can also be fitted with shears to support debris clearance operations. The equipment has a working depth range of 75m to 600m, and can be deployed up to 400-500m offset from an incident well.
Collaboration with Saipem SpA and COMPANY to optimise the design parameters of the buoyancy and engineer a suitable solution that would meet tight deadlines and extremely high quality and density requirements. Like all solutions offered by Matrix safety is paramount and no short cuts were taken. The solution required three uniquely designed buoys (top hatch, top and side tank buoys) which would interface with the ballast tanks. The buoyancy solution weighed ~120 tonnes in air and to provide 200 tonnes of uplift in seawater, the equivalent of a large commercial passenger jet.
CONSTRUCTION AND ASSEMBLY PROCESS
Top tank buoyancy was manufactured as 48 off modular blocks with two configurations. Each configuration was fabricated by bonding 4 modular blocks. The blocks were dry fitted before bonding. The 4 off finished structures each measured Ø3.5m x 4.2m high. When incorporating the side buoys to the ballast the structure measured 12.9m.
Despite a number of challenges the system was dispatched from Henderson on time and on budget with the System Integration Testing (SIT) completed in Italy in 2017. The manufacturing data record (MDR) contained over 1,150 pages of process and product documentation with all key milestones witnessed by both Saipem SpA and COMPANY. The system is stored in 20’ shipping containers ready to be air freighted and deployed anywhere around the globe.