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DECOMMISSIONING INSIGHT
2015
page 40
The weight of a platform will have little effect on some of the expenditure associated with removal, including
removal preparation, vessel mobilisation, sea-fastening, transportation and load-in onshore. This can result in
a larger average cost per tonne forecast for topside removal for the smallest and lightest structures commonly
found in the SNS and Irish Sea regions, compared to larger structures in the CNS and NNS/WofS regions. However,
the cost per platform is significantly lower in the SNS and Irish Sea.
The large range in costs per tonne for both topside and substructure removal seen in the SNS and Irish Sea is
primarily due to the varying approaches to platform removals. Where possible, decommissioning is carried out in
batches or campaigns to maximise efficiency gains and reduce costs. In the SNS and Irish Sea, several operators
plan to remove multiple platforms in one campaign, allowing mobilisation and other fixed costs to be spread
across the structures being removed. Projects at the bottom of the range are typically those included in a batched
approach, while those at the top of the range are typically planned as individual removals.
Figure 21: Historical Variation in the Removal Cost per Tonne Forecasts for Topsides and
Substructures in the Southern North Sea and Irish Sea
0
1,000
2,000
3,000
4,000
5,000
6,000
7,000
8,000
9,000
10,000
2011
2012 2013 2014 2015
2012 2013 2014 2015
Topside and
Substructure
Topside
Substructure
Estimated Cost per Tonne (£ - 2015 Money)
Average Forecast Topside Removal Cost Per Tonne
Average Forecast Substructure Removal Cost Per Tonne
Average Forecast Topside and Substructure Removal Cost Per Tonne
Range in Cost Forecasts
Source: Oil & Gas UK
Removal Cost per Tonne
2014 Average
2015 Average
Topsides
£4,000
£4,600
Substructures
£4,500
£4,400