Islandmagee Storage Project, County Antrim

Islandmagee Storage Project includes the construction of an underground gas storage facility in Islandmagee in County Antrim, Northern Ireland. The underground facility will have an injection capacity of 12m m³/d of gas and withdrawal capacity of 22m m³/d of gas. It is being developed by Islandmagee Storage at a cost of £400m.

Islandmagee Storage submitted a planning permission application to the Northern Ireland Planning Service in March 2010. The application was approved in October 2012. Drilling of a test borehole is now expected to be carried out in the first half of 2013.

The project is expected to take seven years to complete. Construction of above ground facilities, however, is expected to be completed within four years.

The project is being developed to achieve security and flexibility of energy supply in Ireland and the UK. Ireland currently imports 100% of its natural gas requirements and generates 60% of its electricity using natural gas.

About 7% of electricity in Ireland is currently generated from renewable sources, the country is aiming to increase this to 12% by 2012. The Islandmagee Storage project is expected to help achieve this target. The facility will be able to satisfy Northern Ireland’s peak demand for more than two months.

Reasons for location of the Northern Irish storage project

The proposed site is proximate to the sea and the presence of infrastructure in the form of the Ballylumford Power Station and the main gas network, which proves advantageous to the project.

Seismic studies carried out in the area confirmed the presence of a thick Permian salt layer at a depth of 1,500m. The Permian-aged salt found in the Larne area contains low impurities and is ideally suited for development of the facility.

Facilities included in the development

The project includes the development of seven caverns with a total capacity of 500m m³ located 1,400m below the Larne Lough. Each cavern will have a capacity of 70m m³ and will be independently controlled through a sub-surface safety valve.

The caverns will be prepared for storage by solution mining. The process involves pumping of sea water to dissolve the salt present in the caverns and extracting the brine solution back to the surface.

Above ground facilities of the project include a gas plant, a leaching plant, a wellpad and a sea water intake plant. The gas facility will include a compression plant, dehydration plant and metering equipment. It will be located adjacent to Ballylumford Power Station providing easy access to the main gas network.

The leaching plant will feature seawater and brine pumping facilities such as leaching pumps, brine discharge pumps and brine tanks. It will be connected to the wellpad through two pipelines.

The wellpad will be a 110x45m flat pad containing wellheads. The seven caverns will each include a wellhead in cellars below the ground level. The wellpad will be connected to the gas plant and leaching plant through subsurface pipelines.

The sea water intake plant will be located on the eastern shore of Islandmagee. It will pump fresh water to the leaching plant and will be operational only during the construction phase. A brine outfall diffuser will also be operational during the construction phase. It will diffuse the brine solution, produced during leaching of the caverns, into the sea.

Partners with a role in the Islandmagee project / joint venture

The project is a joint venture between Infrastrata UK (65%) and Moyle Energy Investments (35%).

In January 2012, Islandmagee Storage signed an agreement with BP Gas Marketing to fund the appraisal of the project. BP will fund all activities up to the point where a decision on commencing detailed engineering design for the project is taken.

The agreement also includes an option for BP to acquire 50.495% interest in Islandmagee Storage. If BP exercises this option, Infrastrata’s stake in the company will reduce to 32.178% and Moyle’s stake will be 17.327%.