Environment Report 2018

Analysis with Outlier Releases Removed Figure 30 shows the releases by source since 2010 without the outliers of the single large events. The main source was pipework infrastructure, which at 11.7 tonnes accounted for more than half of the total. The single largest release of 2017 was from this category, when 8.24 tonnes of condensate was released from a subsea pipeline. Although the total oil releases once outliers are excluded is higher in 2017 than in 2016, the total mass remains 26 per cent lower than the recent peak in 2013.

Figure 30: Accidental Oil Release Mass by Source Excluding Outliers

10 15 20 25 30 35 40 45 50

350

Hydraulic Systems

300

Subsea Systems & Related Equipment Pipework

250

Infrastructure Containment

200

Bulk Transfer Systems

5

150

Mass (Tonnes)

Drainage Systems

100

Number of Releases

Production Systems & Related Equipment Other*

50

0 5

0

2010 2011 2012 2013 2014 2015 2016 2017

Number of Releases

*Other includes releases from firefighting systems, flare systems, deck washings and unidentified sheen, as well as those releases for which no source is identified.

Source: BEIS July 2018

45