Getting into deep water
Busak+Shamban is a strategic sealing partner with Bluewater and supply them a range of seals for their FPSO vessels. They have worked with them on a number of special solutions. These include a unique split seal for maintenance of a turret mooring system operating in deep water, which minimized down time and loss of income for the operator.
Seal developer and manufacturer Busak+Shamban is a strategic sealing partner to Bluewater who design, develop, manage, construct and operate Floating Production Storage Offloading (FPSO) vessels. These extract and process crude oil in deep water offshore and are an alternative to a fixed rig.
Picture shows swivel stack
There are hundreds of seals fitted on turret mooring systems, the integral component of the FPSO. Its product transfer system contains risers, flexible hoses that connect the subsea piping to the FPSO and a swivel stack linking it to the FPSO piping. The swivel stack provides multiple fluid paths for transfer of gas, water and crude oil. In addition to the swivel stack a utility swivel is used for hydraulics, chemical injection and an electrical/ instrumentation slipring.
The seal within the slipring assembly is of a large diameter, in excess of two meters. An operator required one of these replaced during maintenance and faced the possibility of considerable downtime and therefore loss of income. Exchanging the seal meant complete dismantling of the swivel stack and possible shipment back to land for installation. This was further complicated by it being mid-winter and the FPSO’s location at a considerable distance off the Norwegian coast.
Picture shows Bluewater FPSO vessel
Working together, Busak+Shamban and Bluewater developed a unique innovative solution to replace the seal with the minimum of disruption to the process. A seal was designed to the required dimensions but instead of being in one piece it was split. The original seal was removed without dismantling the swivel stack. The split seal was then fitted in its place, glued and pinned. This required only a few hours of down time instead of several weeks.
“Busak+Shamban has a good understanding and experience within the offshore industry,” says Peter Burger, Head of Engineering at Bluewater. “This allows them to offer proven and innovative solutions. We pride ourselves on being goal driven, creative and flexible. We have found the same qualities in Busak+Shamban.”