The FMC Boom To Tanker (BTT) system has been designed and developed by FMC for offloading of LNG (-160°C), or any other fluid, using the experience gained with a similar system at Brunei. The BTT can be used from a fixed tower, a fixed jetty or from an FPSO (Floating Production Operation System) for tandem loading with significant wave heights of up to 5.5m.
FMC Technologies with extensive experience in offloading LNG since 1963, continues to invest heavily in R&D of improved and new loading systems for land based and offshore applications.
The BTT consists of a boom, a double pantograph system and a manifold assembly installed at the bow of the LNG carrier. Three (3) 16" diameter line ensures the nominal LNG flow rate of a 15000 cubic meter/hour(5000 cubic meter/ hour each), while the vapour return line is 16" diameter. Every line (product lines and vapor return line) is made of stainless steel pipes interconnected with Chiksan® Constant Motion swivel joints. The double pantograph system together with the jumper assemblies at the bow of the LNG carrier, guarantee the six degrees of freedom.
A Position Monitoring System (PMS) is used to permanently monitor the position of the BTT within the operating envelope.This PMS device is directly linked to the double ball valve hydraulic Quick Connect/Disconnect Coupler (QC/DC) system to ensure that the BTT will not be damaged in case of an emergency (overdrift of the LNG carrier or fire on board).
Features
- The BTT system can operate:
- from an FPSO in significant wave heights of up to 5.5m with a flow rate of 15000 cubic meter/hour of LNG at -160°C
- from a Single Point Mooring (SPM) tower and follow the weathervaning of the LNG carrier for up to 360 degrees
- The Chiksan LNG constant motion swivel joints have been tested for a period of three years with liquid nitrogen at -190°C and are also in service at exposed locations since 1993
- The FMC Position Monitoring System (PMS) continuously monitors the relative position of the BTT. It also continuously monitors the relative drift velocity between the LNG carrier and the jetty (onshore unloading) or between the LNG carrier and a FPSO (offshore unloading) to enhance the overall safety of the installation
- The Emergency Release System (ERS) has the ability to disconnect very quickly the double valves using a mechanical/hydraulic device to ensure the BTT system is not accidentally damaged
Benefits
- Reliability and enhanced safety of operations using the system FMC BTT device with fully proven Chiksan LNG constant motion swivel joints on a similar system in Brunei for 23 years
- Proven boom system in the North Sea and Gulf of Mexico
- Ability to service in situ any part of the double pantograph system without the need of any outside lifting equipment reducing the risk of any downtime of the BTT
- Ability of the BTT system to transfer and retrieve the mooring line without the need of a tug boat. Reduced risk of demurrage and of continuation of operations
- The flexibility of the mechanical and control system of the BTT makes it possible to install it at different locations
- Worldwide permanent aftermarket support backed by a financially strong corporation ensures continuation of operations over lifetime of the BTT