Trelleborg Supplies Bespoke Floatover Technology for Harsh Burma Seas
Trelleborg’s engineered products operation has supplied a range of custom floatover solutions to the Saipem Zawtika project in Burma that cater for the harsh environments offshore of the country.
This includes four Deck Support Units (DSU) and Leg Mating Units (LMU), which were manufactured with a larger compression design to cope with waves of over two to three meters / 6.5 to 9.8 feet.
Julian Wee, Managing Director of the Trelleborg Offshore and Construction Singapore operation, adds: “Our clients require diverse levels of customization and the innovative polymer and engineering solutions we provide them with are designed specifically to meet their technological and challenging needs. Installation windows are small and the actual mating process has to be controlled and executed precisely in long periods of swell conditions. Any failure in the LMU assembly system will result in significant damage to the topside and jacket legs. For this reason, all of our LMU systems are tested to the actual specified loads, validating design specifications.”
Leg Mating Units (LMUs)
The custom-designed LMUs for the Saipem Zawitka project were engineered for larger compression. This was realized by achieving a greater displacement measurement of 600mm / 2 feet, compared to the displacement measurement of 500mm / 1 foot 8 inches for a standard LMU.
LMUs consist of steel structures incorporating engineered elastomeric pads and they make a floatover transition possible by damping the forces created as the topside’s load is transferred to the jacket. The elastomeric pads are designed to take up the static and dynamic forces of the topside structure, as well as the horizontal forces due to open sea motions during the float-over mating operation. The assembled LMU can be installed either on the topsides or jacket.
Deck Support Units (DSUs)
DSUs are also important components for safe float-over operations. The topside is loaded onto the vessel with a deck support frame and the DSUs are then placed between them to absorb the weight of the topside. This enables the LMUs and DSUs to work together in synchronization during the installation phase. When the heavy vessel starts to ballast, decompression will occur on the DSUs and vertical compression will occur on LMUs.
The Saipem Zawitka project field is located in Block M9 in the Gulf of Martaban, Myanmar. First production from the Zawtika project is projected at around 345 million standard cubic feet per day (MMscf/d), with the gas being supplied to Myanmar and Thailand.