Environment Report 2018

ENVIRONMENT REPORT 2018

Figure 34: Mass of Accidental Chemical Releases by Hazard Category and Number of Releases

1,000

Unattributable High Medium Low PLONOR Number of Releases

900

800

700

600

500

400

300

200

Accidental Chemical Release Mass (Tonnes)

100

0

2010

2011

2012

2013

2014

2015

2016

2017

Source: BEIS July 2018

The accidental chemical releases from 2010–17 are categorised by source in Figure 34, which shows the annual variation, highlighting the anomalous, largest incidents over the last eight years and reflecting the unplanned nature of the releases. Between 2010 and 2017, production systems and related equipment contributed the majority (1,151 tonnes, 36 per cent) of all accidental chemical releases. Over half of this (651 tonnes) was released during just four incidents. Hydraulic and subsea systems accounted for 900 tonnes and 531 tonnes (28 per cent and 16 per cent), respectively. Together with production systems, these three categories account for nearly 80 per cent of accidental releases by mass over the past eight years. Other notable releases occurred in 2012 when 364 tonnes of oil-based drilling fluid were released following a wellhead blowout and, in a separate incident, 139 tonnes of water-based drilling fluid were released from a wellbore. In 2017, there were four releases over ten tonnes, half as many as in 2016. These came from two sources: three from hydraulic systems, and one from production systems.

Where precise amounts are not known, which is often the case when releases are accidental, operators provide worst-case estimations for each incident and so the actual amount released is likely to be less.

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