Ultra-deep water port: feasibility study

Report compiled by Ernst & Young following their feasibility study looking at the most cost effective locations for an ultra-deep water port in the UK.

Appendix B: Main assumptions and sources of information

In undertaking our work it has been necessary to make a number of assumptions, reflecting that all the required data was not publically available or considered commercially sensitive.

Our main assumptions are set out in the table below

Table 32: Main assumptions



Locational assessment

An UDW port is considered to be a port with a capability of 24m draught directly at the quayside.

To reflect the definition set out in the Invitation to Tender for the Feasibility Study.

Market Demand

UKCS Platforms and Floating Assets analysis

All data used has been collated from the OSPAR list of offshore installations (Based on information contained within OSPAR list of offshore inventory, filtered to remove platforms which have already been removed to shore), which was refined by EY to account for certain installations which have already been removed to shore for decommissioning.

To establish the list of platforms and floating assets for inclusion in the market assessment, adjusting for areas where data is not complete.

Floating assets are excluded from the market assessment.

All floating assets were removed from the list on the assumption these assets can be towed directly to the shore for disposal and recycling.

Small platforms (defined as <8,000tonnes) are excluded from the market assessment

Small platforms are considered less appropriate for reverse engineering heavy left removal and therefore may not require an UDW port capability.

8,000 tonnes is used on account of evidence showing the Thames AP (6,488 tonnes) using the Rambiz vessel.

This assumption is flexed as part of the base sensitivity testing.

Gravity-based concrete structures will be granted derogation by the decommissioning regulation and be allowed to remain in place. This is consistent with the treatment for the Frigg MCP-01 and Brent Alpha platforms

EY makes no representation on whether a particular platform should or will be granted derogation to allow it to remain in place. This adjustment is included in the analysis to allow the prudent assessment of tonnages which may come onshore from decommissioning projects.

Platform removal timelines:

Where a CoP is not available it is assumed platform will reach CoP 35 years after production commences.

Topsides will be removed three years after CoP and a substructure four years after CoP. This assumption was discussed with industry stakeholders who agreed it was a reasonable assumption to make without more detailed analysis or information being available.

To forecast a timetable for decommissioning projects.

The cost per tonne of UKCS onshore recycling and removal is set as £300 per tonne.

This information is considered to be commercially sensitive and accordingly is not publically available. Analysis of OGA figures has allowed to estimate a range of £160 to £305 per tonne. During the market consultation interviewees it was confirmed that £300 per tonne was a sensible estimate, which is also consistent with the OGAs upper range.

Based on this information we have adopted £300 as a reasonable cost per tonne assumption, recognising that it is at the upper end of the OGA range but is consistent with current market views.

Income range for a port set as £35-£50 per tonne.

This information is considered by port authorities to be commercially sensitive and accordingly is not publically available. Industry analysis does not provide published benchmarks of this form of income. Consequently, the lack of data restricts this aspect of the analysis.

Assumption is based on a single comparator project available to EY.

The total tonnage for suitable platforms includes the weight of the 59 platforms that will require both topside and substructure removal as well as the weight of an additional 5 platforms which will require topside removal only.

To reflect that even if platforms are granted derogation the topside will still require removal.

Source: EY

We have also relied on the following sources of information within the main body of the report:


Email: Claire Stanley

Back to top