The Mutineer Exeter (ME) Development during the cessation phase comprises the following:
A subsea production system with a production centre in each of the Mutineer, Exeter, Fletcher and Finucane fields. The subsea production system has been flushed of hydrocarbons with treated seawater in a preservation state. The reservoirs are isolated from the subsea production system although the subsea production system remains connected to the disconnectable turret mooring (DTM).
A DTM lowered to 30 m below sea surface located between the Mutineer and Exeter fields.
For the cessation period between flushing and final decommissioning, all well valves will remain isolated.
During this time, subsea inspections of the DTM and the subsea production system will occur to ensure
ongoing integrity. These inspections and interventions are performed by ROV or diving from a support vessel.
Typical subsea inspection and intervention activities carried out may include:
Spider buoy moorings inspection;
Subsea production system inspection (subsea trees, MPPs and manifolds, multi-phase flow meters
(MPFMs), flowlines, jumpers, integrated services umbilicals (ISUs), production umbilical distribution
units (PUDUs), umbilical termination assembly (UTAs), etc.).
Riser and umbilical inspection;
Cathodic potential measurements;
Subsea equipment intervention, e.g. operating valves;
Debris clearance;
Diving activities;
Sediment grab sampling; and
Recovery of dropped objects.
 
note: this information has been extracted from the Environment plan submitted