The Woollybutt Field is located in the Carnarvon Basin, off the North West coast of Australia, 23 nautical miles west of Barrow Island.
As additional in-field well, Scalybutt was connected as a step-out well to the existing Woollybutt Field during December 2005.
Woollybutt recoverable reserves were estimated to be approximately 35 million barrels of oil (mmbo) and the field is currently anticipated to be in production for approximately three years.
Premuda converted an existing trading tanker into the Floating Production Storage Offloading (FPSO) “Four Vanguard” for the field development, with process equipment installed on the main deck. This process system has been designed to accommodate the production requirements of ENI Australia Ltd (EAL), including provision of gas lift facilities, and the process plant has been kept independent of the vessel systems as far as possible to minimise interface engineering and operation.
The FPSO is fitted with a disconnectable single point mooring (DSPM) system, which takes the form of a swivel and buoy combination. The buoy is held by a hydraulic quick connect / disconnect (QCDC) clamping arrangement within a moonpool. The buoy is moored by means of six anchor chain legs to drag anchors on the seabed.