A floating semi-submersible platform was built to mine liquid natural gas (LNG) from an extensive gas field, which has been discovered in the Timor Sea, off the North-West coast of Australia.
The LNG is extracted by means of a number of hoses called umbilicals. Hydrauvision has contributed to this project, called Ichthys, by providing the suction spread, including winches, hoses and water pumps. The Ichthys project is one of the largest LNG projects in the world.
Underneath the floating platform, a riser support structure (RSS) was installed on the seabed. This RSS tower has a height of 110m. The structure was sunk vertically and pulled into the seabed by its own weight. That is why it is called a ‘suction anchor’. It comprises a rectangular U-frame measuring 70m x 40m, with the open end pointed downwards. Subsequently, the compartments were pumped out, resulting in a vacuum. This caused the anchor to pull itself firmly into the seabed.
After the construction period, the system was tested. To this effect, we designed a basin to serve as an underwater environment. After a number of days and nights of intensive testing, it turned out that everything functioned according to the design. Next, the Ichthys Suction Spread was assembled and installed in Batam, Indonesia. After that, the installation was transported to Australia on board the Aegir. Hydrauvision’s Suction Spread is a crucial part of the LNG-mining system.
The distance between the seabed and the platform is 250m. To bridge the remaining 140m, various umbilicals have been connected to the support structure. A pump frame has been installed on top of the suction anchor. This pump frame has a width of 6m, a depth of 2m and a height of 2m. It contains four water pumps, which have been modified by Hydrauvision Systems and provided with a hydraulic driving motor.
The hydraumotors are driven by Hydrauvision Rental powerpacks, which are placed on deck. The powerpacks are connected to two umbilical winches, each of which has five umbilicals (press-return-press-return, leak). These hoses are connected at a depth of 250m by means of a remote operated vehicle (ROV).
The result: Hydrauvision has once again proven its knowledge and experience by designing and building the Ichthys Suction Spread. Another fine example of the excellent collaboration among the Hydrauvision divisions: systems, rental, and service.
For more information, please contact HydrauRent.