PEOPLE walking the riverside around Monkstown in Cork Harbour over the past week have been asking: What is the structure moored to the outer section of Ringaskiddy Pier?
It is the visual evidence of ‘the end of an era’, brought from the biggest offshore maritime project now underway in Ireland.
As our photograph, taken 35 nautical miles off the Cork coast, shows, that is an extensive operation, costing millions of euros, involving specialised vessels and equipment. It is out of public sight, so the moored structure at Ringaskiddy has caused curiousity.
Looking at it from one of the shoreside seats along the Strand Road in Monkstown this week, I remembered being aboard helicopters hovering above the Kinsale Head gas-rig platforms, Alpha and Bravo, of which the moored structure was part. Viewed from a chopper, they were impressive, giant, steel structures.
Alighting, you kept your head down, careful of rotating blades as you crossed to steps descending to living and working quarters.
The food was good. I remember being impressed, looking out to sea all around from an engineering marvel, perched above a seabed, from where energy that was hundreds of millions of years old was being extracted.
The structure moored at Ringaskiddy is part of those Kinsale Head gas rigs, removed in decommissioning. It is awaiting towage for final disposal.
Since operations started back in 1978, the Kinsale Head gas field project was out of sight to the general public.
Exploration for offshore oil and gas had begun in Ireland during the early 1970s. The Kinsale field was discovered in 1971 by the US company Marathon Oil Corporation at a depth of 90m, the largest single hydrocarbon discovery in Ireland.
A number of satellite gas fields were found and connected to the platforms between 1990 and 2003, including Ballycotton, in 1991, Southwest Kinsale, in 1999, and Seven Heads, in 2003 (developed by Ramco Energy). At peak production in the mid-1990s, with 24 wells, Kinsale Gas enabled Ireland to be self-sufficient in supply and was instrumental in developing the national natural gas network. “Exceptionally pure gas from undersea sandstone through layers of shale and chalk,” I reported from one of those media trips to the rigs.
PSE Kinsale Energy Limited took over from Marathon and Kinsale remained Ireland’s only indigenous source of natural gas until 2015. It gave a lot of employment until eventually it was depleted. Production ceased on July 2, 2020, after two trillion cubic feet of gas was extracted over 42 years. Thousands of tonnes of concrete are being used to cap the wells. Platforms Alpha and Bravo, where many people lived and worked, are to be recycled in northwestern Europe. Pipelines, cables, subsea structures associated with the drilling, and the onshore terminal are included in the decommissioning.
The rocks that yielded the gas were formed in the Cretaceous geological era, around 100m years ago. That shows how long maritime Cork has been around!
According to industry information, there are at least 12,000 offshore oil and gas platforms worldwide. As they drain their reservoirs of fuel below the sea surface, they become defunct when they extract too little to be profitable.
“The big question is what to do with these enormous structures, particularly the underwater sections, when the fuels stop flowing,” said an expert, “because the number of defunct rigs in the oceans is set to get bigger.”
Kinsale Energy confirmed to me this week that “all of the platform structures on both Alpha and Bravo platforms are being fully removed as part of the decommissioning project. This includes the topsides (above water structure) and the jackets (under water structure).”
“The work will continue until August,” Fergal Murphy, CEO, PSE Kinsale Energy, said.
“Platform-removal activity is being carried out by Heerema Marine Contractors using the semi-submersible, self-propelled crane unit, ‘Thialf’, and associated vessels. The ‘Thialf’ is removing the platforms in a number of sections, which are then backloaded onto cargo barges. The backloading of the removed components is taking place at the offshore platform locations. We are entering the final phase of decommissioning, in accordance with consent from the Department of the Environment, Climate, and Communications.”
Definitely, the ‘end of an era.’