Environment Report 2015

ENVIRONMENT REPORT 2015

Discharged Drill Cuttings Figure 22 shows the distribution of drill cuttings discharged to sea across the operators on the UKCS in 2014. The amount discharged depends on the length of wells drilled 43 ; the longer the well, the more drill cuttings produced. In 2014, just under 90 tonnes of cuttings were discharged per million tonne of hydrocarbons produced, compared with just under 110 tonnes per million tonne produced in 2013. In 2014, almost 280 tonnes of cuttings were discharged per well drilled, which is lower than the 2013 value (340 tonnes per well drilled). Last year, only three of the 33 operators reporting in this category recorded discharge of oil-based mud cuttings. Discharge of untreated oil-based cuttings is not permitted on the UKCS and so all of these assets have on-board drill cuttings treatment systems to clean any discharged cuttings to the permitted standard (less than one per cent oil content). An increase from 2013 of 4,000 tonnes of oil-based cuttings discharged indicates that more on-board cleaning is being carried out, reducing pressure on onshore waste treatment and disposal options. Alternative routes for cuttings disposal include shipping to shore, injection and leaving in the well.

Operators A to L are those that either carried out no drilling in 2014, or shipped all their cuttings to shore for remediation and disposal.

Figure 22: Cuttings Discharged to Sea per Operator in 2014

8,000

Oil-Based Cuttings

7,000

Water-Based Cuttings

6,000

5,000

4,000

3,000

Discharged Cuttings (Tonnes)

2,000

1,000

0

A C E G I

K M O Q S U W Y AA AC AE AG

Source: EEMS June 2015

43 Data on the length of wells drilled were not publically available for 2014 at time of writing.

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