Sinopec Oil and Gas Australia (Puffin) Pty Ltd (SOGA), a wholly-owned subsidiary of China Petrochemical Corporation (Sinopec), as Operator of Petroleum Retention Lease 11 (AC/RL11) in the Ashmore and Cartier Area of the Bonaparte Basin, operates the Puffin Development.
The Puffin Field is located in AC/RL11 and covers an area of approximately 900 km2 in the Vulcan sub-basin in water depths ranging from 75 to 104 m, and is located 88 km east of Cartier Island, 255 km from the nearest Australian mainland, 670 km northwest of Broome and 706 km west of Darwin.
Oil was first discovered in the Puffin field in 1972 with the drilling of Puffin-1. Oil was produced through a Floating Production, Storage and Offloading (FPSO) vessel from two wells (Puffin-7 and -8). The FPSO departed the field in July 2009 after having produced 2.2 MMbbls of crude oil (of an expected 90 MMbbls). Since this time, the Puffin Field subsea equipment has been managed under a care and maintenance regime by Upstream Production Solutions (Upstream P.S.) on behalf of SOGA.
Upstream P.S. is the registered Facility Operator of the Puffin Field under the Offshore Petroleum and Greenhouse Gas Storage (Safety) Regulations 2009. SOGA is the registered Operator under the Offshore Petroleum and Greenhouse Gas Storage (Environment) Regulations 2009 (OPGGS(E)).
From August to November 2014, the Stena Clyde drilling rig permanently plugged and abandoned (P&A) the Puffin-5, -7, -8, -9, -10, -11 and -12 wells and recovered the Puffin-7 and -8 subsea trees. This program was managed by AGR Australia Pty Ltd (AGR) on behalf of SOGA. This effectively removed any connection to any hydrocarbon reservoirs or any surface facility connection.
The remaining equipment in the field consists of a manifold, static and dynamic flowlines, pipeline end manifolds (PLEMs), concrete mattresses, anchors and chains, dynamic riser clump weights and the field marker buoy and its clump weight.
SOGA proposes to decommission the Puffin Field, removing all equipment from the seabed, water column and sea surface. It is proposed that a full size Construction Support Vessel (CSV) will be used to perform the decommissioning activities. This type of vessel is suited to deep-water operations, using dynamic positioning (DP) capability to avoid the need for anchoring. The Puffin Field Decommissioning Field is scheduled to commence in late 2015 or early 2016, with timing subject to vessel availability and weather conditions.
Decommissioning activities are expected to take up to 30 days on location, with the vessel operating 24 hours per day. At-sea refuelling is not required.