Repsol Sinopec preparing for decommissioning of UK North Sea field

Oil and gas company Repsol Sinopec has received approval from the UK authorities for preparation work scopes plan relating to the decommissioning of the Fulmar and Auk North installations located in the UK sector of the North Sea.

Prior to formal approval of the Fulmar and Auk North Decommissioning Programmes (facilities) and DP (jacket), there are a number of decommissioning scopes that are required to be progressed to prepare for final decommissioning.

Repsol Sinopec’s document, which has now been approved, contains the decommissioning scope of work that will be executed prior to formal approval of the DP (facilities) and DP (jacket).

These scopes include the development of the decommissioning programme including all studies, platform surveys, development of well abandonment solutions for the Fulmar A wells (Fulmar and Halley), Fulmar AD wells, and Auk North Wells; development of stakeholder engagement plan to present and facilitate engagement sessions with stakeholders; asset operations transition planning; Fulmar AD well abandonment; and Fulmar A well intervention (Fulmar and Halley Wells).

In addition, the scope also includes Fulmar A Well Abandonment (Fulmar and Halley Wells) including platform rig upgrades, commitments to module rigs, or hydraulic workover units or any potential topside removal; upgrade of platform utility and safety systems will also be required to support the well abandonment operations based on a platform-based solution. The scope may take the form of inspection, modifications/upgrades as part of the enabling scopes to ensure that they are suitable to support the abandonment scopes;

Finally, the work scoped include engineering, down and cleaning of Fulmar A and Fulmar AD production facilities and supporting utilities.

The Fulmar complex, comprising the main Fulmar Alpha platform and the bridge-linked Advanced Drilling (AD) wellhead jacket, is a fixed offshore drilling, production and accommodation installation, located in Block 30/16 of the Central Sector of the North Sea.

The installation stands in 83m of water approximately 350km east of Dundee.

Development of the Fulmar field began in 1978 with first oil produced from the AD wellhead jacket to the Floating Storage Unit (FSU) in February 1982, followed by first oil from Fulmar Alpha in May 1982. Fulmar Alpha currently has 36 well slots and Fulmar AD has six well slots.

Fulmar Alpha imports metered oil from Clyde/Orion and Auk Alpha. The oil imports are combined within the oil export module (OEM) before being metered and exported via a subsea pipeline to the Norpipe system for onward processing at Teesside. Fulmar Alpha also receives conditioned metered Clyde gas for export via the St. Fergus pipeline.

The Auk North reservoir is located approximately 10.5 km southwest of the Fulmar Alpha platform and was developed as a subsea tie-back to the Fulmar Alpha platform.

The development was produced from four wells each utilizing dual electric submersible pumps (ESP), which are tied back to the Auk North subsea manifold and onto the Fulmar Alpha platform via an electro-hydraulic control umbilical, flowline and conductor/riser arrangement.

Within the Fulmar field are two redundant single anchor leg mooring (SALM) bases that supported the original oil export route from Fulmar Alpha via shuttle tanker. The SALM Bases were included within the previously approved Fulmar Oil Export Decommissioning Programme indicating that they will remain in situ to allow for potential re-use.

The programme also stated that should no further use be identified the SALM Bases will be decommissioned at the same time as the other facilities in the Fulmar fields.