Decommissioning and abandonment

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Decommissioning and abandonment

LINE REMOVAL CHECKSHEET

ƒ Environmental issues ƒ Soil disturbance – seabed modification issues ƒ Coral – primary or secondary growth (on pipe) ƒ Disposal of steel ƒ Disposal of concrete and other coatings ƒ Disposal/storage of residual contents ƒ Health and safety issues ƒ Divers hours at depth ƒ Handling of pipeline offshore and onshore ƒ Radioactivity of residual product ƒ Proximity of live adjacent assets or adjacent pipelines This and the following slides show some of the issues that must be considered when carrying out an assessment and selecting the best removal method. When using this list to determine weightings, remember it all depends on your perspective! Thus, it is recommended that wide advance stakeholder engagement helps. Cost estimates should be undertaken for each option. ƒ Pipeline criteria ƒ Burial condition – additional costs for unburial ƒ Diameter – larger lines more expensive ƒ Overcrossings – cut 30 m (100 ft) either side ƒ Cannot reverse lay – requires cut-and-lift options ƒ Heavy corrosion or build-up prevents cleaning ƒ Injury to personnel hot cutting or spillages to sea ƒ Piggability – may require fitting of temporary pig traps ƒ Line integrity for removal – strong enough to lift ƒ Water depth – use of ROVs or divers to recover ƒ Removal of mattresses and crossings ƒ Re-qualification of lifting points LINEREMOVALCHECKSHEET LINE REMOVAL CHECKSHEET

LINEREMOVALCHECKSHEET