Kinsale Head gas field to be decommissioned

Rig Alpha, part of the Kinsale Head Gas Field. The decommissioning work, which will take several years to complete, will include the removal of two giant off-shore rigs — Kinsale Alpha and Kinsale Bravo — which were installed as part of the initial field development in the late 1970s; and the plugging of wells.

A massive decommissioning of one of Ireland’’s largest gas fields has been approved as its reserves are about to be exhausted.

The Department of Communications, Climate Action and Environment has formally consented to the plan submitted by Kinsale Energy Ltd for its Kinsale Head gas field site, some 50km off Cork.

The work, which will take several years to complete, will include the removal of two giant off-shore rigs - Kinsale Alpha and Kinsale Bravo - which were installed as part of the initial field development in the late 1970s; and the plugging of wells.

The Kinsale Head, Ballycotton, Seven Heads and South-West Kinsale gas fields have been in production since 1978.

The gas found was exceptionally pure and required only the removal of associated water to ensure it met the required quality levels for use.

This conditioning work was carried out on the offshore rigs before the gas was compressed to raise its pressure for transport, via a 24-inch sub-sea pipe, to the Kinsale Energy terminal at Inch near Midleton.

It was then metered before being transferred to Gas Networks Ireland (GNI) for distribution nationwide.

The Kinsale gas fields, which were developed right up to 2003, supplied all of Ireland’s natural gas from 1978 to 1995 before others came on stream. They were Ireland’s only indigenous source of natural gas until 2015.

But it is anticipated that the gas reserves will have been depleted by the end of this year or 2021.

By the time production ceases, almost two trillion cubic feet of gas will have been produced - double the original reserve estimate.

Ahead of that, the company prepared a detailed decommissioning plan for submission to the department for approval.

It included plans to permanently plug all wells in the Kinsale Head field and to decommission all associated facilities such as the rig platforms, the pipelines, cables, sub-sea structures and the onshore terminal at Inch.

In formal public notices published today, the department said having carried out an environmental impact assessment in relation to the plan, the Minister has concluded that subject to the implementation of the various mitigation measures proposed by Kinsale Energy Ltd, and subject to compliance with various conditions, the work will not result in significant adverse effects on the environment.

The validity of the decision can still be appealed via judicial review.

The company previously said that there is a possibility that some of the facilities, such as the platform support structures - the structures below water which support the rigs, and which are known as jackets - or some of the pipelines, could be used as part of a gas development project, a renewable energy project or to support carbon dioxide storage in the depleted gas field in the future.

Kinsale Energy, which employs 60 people at its onshore and offshore facilities, is a subsidiary of the Malaysian oil and gas company, Petronas, which acquired the company in April 2009, from its previous owners, Marathon Oil.

Although there has been a lot of exploration for additional gas reserves in this area of the Celtic Sea over the years, no other commercial gas discoveries have been made.