The entire Project for the disconnection and demobilization of the FPSO was managed in four stages. The first two stages were related to shutdown of the production, flushing of all flexible flowlines and preparing the FPSO for the disconnection by cleaning the topsides, disconnecting of spools and installing of pulling heads.
The latter phases were aimed at disconnecting all production risers, umbilicals and mooring chains from the FPSO for its sail away. The Decommissioning of the FPSO was carried out through detailed engineering aimed at identifying the best option suitable for early sail away.
The field decommissioning campaign was successfully completed without damage to assets and resulted in an early departure of the FPSO. Innovative tools were used to close the subsea valves resulting in significant reduction in offshore time and cost saving. The use of different methods to disconnect flowlines and mooring chains was a winning choice to cover challenges which occurred during the offshore execution.
Overall Project was very successful with early FPSO sail away which was achieved with primary focus on safety and the environment throughout the duration of the Project: Right planning through to closeout, to reach no Loss Time Injury (LTI) outcome.
The Floating Production Storage and Offloading Unit (FPSO) was located in Timor Sea approximatively 500 km off the Australian coast and 150km south of Timor-Leste. The field comprises of three subsea production wells in water depths of about 320 m. These wells were tied back to an internal turret in the FPSO which was moored in approximately 325m of water depth.