Ireland Assessment of Discharges, Spills and Emissions from Offshore Oil and Gas Installations
2018 - 2023
Executive Summary
This report presents the discharge, spill and emission data for Irish offshore oil and gas operations during the period 2018 – 2023 and provides an assessment of that data. The annual data on which the assessment is based are provided in Annex 2.
Full Report
Level of Activity
Levels of oil and gas drilling and production activity offshore Ireland have historically been low. Up to 2015 there was just one gas production facility, though with multiple well inputs from three gas fields. An additional gas production facility began operations at the end of 2015 but did not discharge produced water to sea over the period of this report. There has been no oil production in Irish waters.
The total production of gas from offshore Ireland has decreased during the period 2018 – 2023.
Discharges & Spills of Oil
The total quantity of dispersed1 oil (aliphatic oil) discharged to the sea from produced water and displacement water in Irish waters decreased from 2018 levels and reduced to zero in 2022.
All levels were below the current performance standard of 30 mgl-1 dispersed oil in produced water discharged to the sea and so the OSPAR performance standard was consistently achieved over the reporting period.
Quantities of oil spilled were low, with two incidents in 2021 totalling 0,01 tonnes. There were no other oil spills reported for the period of this assessment.
1 “Aliphatics” and “aromatics” are defined by the reference method set in OSPAR Agreement 2005-15 (Solvent extraction, Infra-Red measurement at 3 wavelengths). In that context, “aliphatics” and “dispersed oil” mean the same thing.
Chemicals
The total quantity of chemicals discharged into the sea during the period 2018-2023 remained in the same order of magnitude or lower than previous years, with any increases associated with drilling and decommissioning. In general, over the assessment period more than 90% (by weight) of the chemicals discharged over the assessment period were on the OSPAR PLONOR list2, apart from one year where the overall chemical use was very low. In the same period, an average of less than 5% (by weight) of the total amount of chemicals discharged contained substances which are candidates for substitution.
OSPAR Recommendation 2005/2 set environmental goals for the reduction of discharges of LCPA substances, and discharges were to be phased out by 2010. This measure was achieved by Ireland, with no LCPA discharges in the assessment period.
OSPAR Recommendation 2006/3 set environmental goals on the phasing out of discharges of chemicals that are, or contain, substances identified as candidates for substitution by 2017. In Irish waters, quantities of such chemicals used and discharged have been historically low. Increases occurring since 2017 are due to one off activities, such as drilling and decommissioning.
2 Poses little or no risk to the environment - PLONOR
Atmospheric Emissions
Atmospheric emissions from offshore oil and gas activities are not regulated by OSPAR measures but are reported annually by operators. Emissions to the atmosphere generally decreased over much of the period, apart from 2019 where increases were attributed to the increased diesel consumption required for dynamic positioning (DP) during drilling of a deep-water well.
Concluding Comment
The level of activity from offshore industry in Ireland has been considerably lower than in most other OSPAR Contacting Parties. Since decommissioning operations in 2021, there is now one subsea facility, with no discharges other than hydraulic valve discharges. As a result of this low level of activity, any additional activity impacts significantly on the data and thus impacts on any trends within.