Oil & Gas UK Decommissioning Insight 2014

There is a higher forecast cost per tonne for topside and substructure removal in the southern North Sea and Irish Sea (see Figure 16). This could be attributed to the fact that a vessel will have the same mobilisation costs for removing a small 500-tonne NUI or a larger structure, as well as due to the longer duration of removals in the CNS and NNS areas which, in turn, reduce the cost per tonne. Although the cost per tonne is higher in the SNS and IS, the variation across the UKCS is relatively small. Figure 16: Historical Variation in the Removal Cost per Tonne Forecasts for Topsides and Substructures in the Southern North Sea and Irish Sea (2011 to 2014 Surveys)

1

2

3

10,000

4

8,000

6,000

5

4,000

2,000

6

Estimated Cost per Tonne (£)

0

2011

2012 2013 2014

2012 2013 2014

7

Topside & Substructure

Topside

Substructure

Average Forecast Topside Removal Cost Per Tonne Average Forecast Substructure Removal Cost Per Tonne Average Forecast Topside & Substructure Removal Cost Per Tonne

Range in Cost Forecasts

Source: Oil & Gas UK

Removal Cost per Tonne

2013 Average

2014 Average

Topsides

£3,600 £5,700

£4,000 £4,500

Substructures

31