Environment Report 2014

ENVIRONMENT REPORT 2014

3.2.1 Produced Water Volumes The UKCS is a mature basin and production has been falling since the early 2000s. As reservoirs deplete, oil and gas extraction requires greater energy input and management of larger volumes of produced water. Indeed, in 2013, produced water accounted for 71 per cent of the total well stream fluids. Nonetheless, for the past decade, the volumes of produced water discharged to sea have been declining, from a peak of 273 million m 3 in 2002 to 150 million m 3 in 2013. This is the result of careful management of produced water, application of the best available techniques and reinjection of produced water.

Figure 1: Discharge and Reinjection of Produced Water from 2000 to 2013

Produced Water Discharged

Produced Water Reinjected

350

300

250

150 Million m 3 200

100

50

0

2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013

Source: EEMS June 2014

From 2001, the volumes of produced water reinjected into the reservoir for oil recovery or disposal has increased. Over the past five years, reinjection volumes have stabilised at around one fifth of the total volume. In 2013, 40 million m 3 of produced water, representing 21 per cent of the total produced water (190 million m 3 ), was reinjected.

However, reinjection is not always technically feasible on installations, nor may the reservoir be suitable. Reinjection also consumes additional energy and therefore may not always be the best environmental option.

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