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ENVIRONMENT REPORT
2016
Gas Venting
Gas venting releases natural gas associated with production directly into the atmosphere without ignition. Venting
is a safety mechanism to release gas pressure when a safe level may be exceeded.
Venting is also subject to consent under the Petroleum Act 1998 through application to the OGA. Applications
undergo a detailed review and those operators that vent over five tonnes per day will be reviewed annually. All
venting activity must be reported in EEMS.
Almost 41,000 tonnes of gas were vented on the UKCS last year, a 10 per cent increase on 2014 in line with the
percentage rise in production. Just under 558,000 tonnes of CO
2
e were emitted from venting on the UKCS in 2015,
which is approximately a sixth of that released through gas flaring.
Gas venting is reported under EEMS as either operation, maintenance, emergency or gross. Gross is reported
when a breakdown is not available and could therefore be any of the other categories; the majority falls into this
category, as shown in Figure 13. When excluding gross, operational (equivalent to routine for flaring) accounts for
the greatest proportion of emissions in each year.
Figure 13: Breakdown of Gas Venting by Source
0
5,000
10,000
15,000
20,000
25,000
30,000
35,000
40,000
45,000
50,000
2010
2011
2012
2013
2014
2015
Total Gas Vented (Tonnes)
Gross
Emergency
Maintenance
Operational
Source: EEMS July 2016
The largest proportion of gas vented between 2010 and 2015 was in the NNS (41 per cent). This is likely due
to the presence of older and larger integrated platforms in this area. Gas venting is also associated with
natural gas production and so the gas-producing SNS region has the second largest percentage of vented emissions
(31 per cent).
Installations less than ten years old (12.5 per cent of reporting platforms) are the smallest contributors to gas
venting on the UKCS (just over 2.5 per cent) between 2010 and 2015. This indicates that this activity is being
minimised through design of these installations and, in turn, the new developments in the W o S mean this area
vents smaller proportions of gas at 2.3 per cent.