Investigation finds IT upgrade responsible for Corrib gas release

‘Deficiencies’ led to non-odourised gas emergency plan being put in place as a result

Shell E&P Ireland has been burning off or “flaring” the odourless gas at the Corrib gas refinery in Co. Mayo since early Thursday morning. Video: Terence Conway

An investigation by the State’s energy regulator into the release of non-odourised gas from the Corrib gas refinery in north Mayo last year says it was caused by the upgrading of an information technology (IT) system.

“Deficiencies” in Shell E&P Ireland’s (SEPIL) operating procedures led to the incident last September, but there were no safety consequences for staff at the Corrib gas refinery or members of the public “in the immediate vicinity”, the Commission for Regulation of Utilities (CRU) has found.

However, the risks to consumers from gas which had no safety odour prompted Gas Networks Ireland (GNI) to activate the natural gas emergency plan. Some 10,000 customers in the Galway-Mayo region were told to shut off their supplies.

The energy regulator says it took “enforcement” actions against Shell and GNI, the national gas networks operator, as a result of its investigation.


No fines were imposed on Shell or on GNI, under a series of enforcement options which the State energy regulator says are “progressive in nature”.

In a report published on Wednesday, the CRU says the incident occurred on September 21st, 2017, during a “re-start process of the terminal, following a planned maintenance shutdown, where upgrades to the IT systems were carried out.

“The IT upgrades caused the odourant injection system to default to a mode where there was no injection of odourant,” it says.

“The operating procedure covering the start-up process did not include a step requiring the operator to reset the odourant system to inject odourant,” it says.

The non-odourisation was identified by Shell as part of normal checks at 2.30am that same day, and GNI was “immediately alerted”.

The natural gas emergency plan was activated at 7am that day, it says, and “ all affected gas was directed back to the terminal and flared off, in order to remove the non-odourised gas from the system.”

The report does not make any reference to the impact of this flaring on local residents living around the refinery.

The energy regulator says that it directed Shell and partners to “submit an improvement plan to address issues identified with operating procedures”.

“The remedial actions set out in that improvement plans have been put in place and the SEPIL enforcement action is now closed,” it has said.

The investigation also found some “deficiencies” in GNI’s compliance with its accepted safety case relating to injection of odour into gas.

The energy regulator says that it issued an “improvement notice” to GNI to address the risk of non-odourised gas entering the national gas network. This required “two actions” to be completed by July 1st this year, and a third by December 31st, 2019, it says.

“GNI provided submissions for the initial two actions ahead of the July deadline,” the energy regulator says, and “evaluation of these submissions and monitoring of the remaining action is ongoing”.

Separate investigations into the incident were initiated by the Environmental Protection Agency (EPA) and Shell E&P Ireland, as operator of the Ballinaboy gas refinery.

The EPA said that any enforcement action would depend on the outcome of its inspectors’ report.

Minister for Rural and Community Development Michael Ring said at the time that “people in Mayo and Galway deserve an explanation of how this was allowed to happen” and said that measures should be taken to “ensure it cannot happen again”.

Stakes sale

A spokesperson for Shell E&P Ireland Limited (SEPIL) said: “SEPIL acknowledges the findings published in the report by the Commission for Regulation of Utilities regarding the entry of non-odourised gas into the transmission network in September 2017. We can confirm that all remedial actions outlined in the improvement plan have been completed.’’

Shell announced last year that it was disposing of its 45 per cent stake in the Corrib gas field to a unit of Canada Pension Plan Investment Board in an €830 million deal, resulting in about €1 billion of losses.

The decision was announced just over 18 months after first gas finally flowed from the field 83km off the Mayo coast, after over a decade of opposition to location of the refinery onshore with a high pressure inshore pipeline.

Just two days after final operating consent for the controversial project was issued by then energy minister Alex White, Shell was prosecuted by the EPA for an intense flaring incident on New Year’s Eve, 2015.

Flaring is activated if there is a pressure rise in the plant, or a fire or gas release, and is permitted “for safety reasons or for non-routine operational conditions” under the license awarded by the EPA.

A recent inquest into the death of a German contractor who sustained head injuries during construction of the Corrib gas tunnel in 2013 returned a verdict of death due to a workplace accident.

Lars Wagner (26), a hydraulics technician originally from Hohberg-Diersburg in Germany, was struck on the head by an inlet pipe connected to a tunnel boring machine that collapsed on September 8th, 2013. He had been employed by Herrenknecht AG, who manufactured the machine used in constructing the final phase of the Corrib gas project.

Contractor Wayss & Freytag was fined €300,000 last year after pleading guilty to health and safety legislation breaches which led to the death of Mr Wagner. At the inquest in late June in Ballina district court, the coroner noted that Mr Wagner’’s death was a “shocking occurrence” .

Lorna Siggins

Lorna Siggins

Lorna Siggins is the former western and marine correspondent of The Irish Times