Environment Report 2019

ENVIRONMENT REPORT 2019

The composition of the UKCS total flare emissions for 2018 is 99 per cent carbon dioxide and 1 per cent methane, which indicates efficient combustion practices overall.

Figure 4: UKCS Total Flare Gas Composition

N₂O 0.00%

VOC 0.44%

CO 0.26%

SO₂ 0.01%

CH₄ 0.46%

NOₓ 0.05%

CO₂ NOₓ N₂O SO₂ CO CH₄ VOC

CO₂ 98.77%

Source: EEMS May 2019

Gas Venting Venting is also subject to consent under the Petroleum Act 1998 through application to the OGA. All applications undergo a detailed review and all venting activity must be reported in EEMS. Just over 95,100 tonnes of gas were vented on the UKCS last year, a 53 per cent increase on 2017. Nearly half of that total was due to a single installation with no gas export facility, where the gas emitted had a carbon dioxide content too high to enable ignition of the flare. The reservoir conditions have since changed, enabling the gas to be combusted via the flare system. The release of gas through venting or flaring is controlled through the consent process by the OGA. As part of the approval process operators must consider other preferable options such as gas recovery where this is practicable and consult key stakeholders on the potential effect of releases of GHGs. The OGA is obliged to consider both the environmental impact and the economic feasibility of production. Gas venting is reported under EEMS as either operational, 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 5.

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