Decommissioning and abandonment

Decommissioning and abandonment

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LINE REMOVAL CHECKSHEET

ƒ Future liability ƒ Fishing – snagging of nets on disturbed spoil ƒ Tourism – diving on coral areas ƒ Other operators – future use of area ƒ Reputation / stakeholder views – rubbish left behind ƒ Possible benefit to fishing – providing shelter ƒ Future management/monitoring – none, if removed ƒ Remaining life – remove whole infrastructure at EOFL ƒ Future lines – require more crossings ƒ Use of local contractors – may need new expertise ƒ Precedence – may set standard for line removal

Where:

EOFL = end of field life

BSEE(FORMERLYMMS) COSTESTIMATES(2004)

BSEE (FORMERLY MMS) COST ESTIMATES (2004) ƒ Gulf of Mexico – local equipment ƒ Total of over 4320 km (2683 miles)

ƒ 62% in range 101.6 mm to 323.8 mm (4 in to 12¾ in) ƒ 3.2% over 762 mm (30 in) ƒ Shallow water depths, 60 m to 150 m (200 ft to 500 ft) ƒ Initially concentrating on nearshore, and areas where with shrimp trawler interaction is likely ƒ Typical pipeline length 6.5 km (4 miles) ƒ Does not include onshore costs ƒ Crossings and other difficult sections excluded

The above cost estimates are taken from BSEE (formerly MMS) paper 32.701.001/R1 of 2004. They refer to the Gulf of Mexico and assume that a suitable barge could be adapted within two days mobilisation/demobilisation. For other areas of the US – fields such as Alaska or California, where there are much shorter lengths of pipeline (>2% of total) to be recovered – sailing costs become significant for specialist equipment and expertise.