Gas fields don’t last forever. Once one stops paying for itself, you plug the wells, take the platforms apart and haul the steel back to shore for scrap. That’s the usual routine, anyway.<\/p>\n
Three old gas fields under Liverpool Bay, the stretch of the Irish Sea between northwest England and North Wales, are getting a different ending. On October 8, Italian energy company Eni said its carbon storage venture with BlackRock’s Global Infrastructure Partners had finished installing a brand-new platform out there called Douglas CCS. It’s built to take carbon dioxide from factories on shore and send it down into the same rock the gas came out of.<\/p>\n
Eni’s announcement<\/a> calls Douglas the first offshore platform anywhere that’s been purpose-built to store carbon from industry. A lot of the plumbing it’s hooked up to is secondhand, though. The CO\u2082 will reach Douglas through a pipeline that spent years carrying natural gas in the opposite direction, then leave through more old gas lines on its way into three depleted fields.<\/p>\n So is it really the first?<\/p>\n Depends on how you count. Norway’s Northern Lights project, which gets its CO\u2082 from ships that haul it in liquid form<\/a>, already stores factory emissions under the North Sea. Its wells sit right on the seabed, though, and there isn’t a platform over them. The other three platforms in the Liverpool Bay network are old gas platforms getting new topsides. That’s a pretty narrow category, and as far as I can tell, Douglas is alone in it.<\/p>\n Three big chunks of steel. If you’ve never had a reason to learn platform anatomy, the jacket’s the four-legged frame that stands on the seabed, and the topsides are the deck and all the equipment that’s bolted to it. Eight steel foundation piles pin the whole thing to the bottom.<\/p>\n By Eni’s numbers, the topsides weigh 2,078 tons and the jacket weighs 1,935 tons. The eight piles add another 805 tons between them, which puts the whole platform at a little over 4,800 tons. Offshore magazine reports that Italian fabricator Rosetti Marino built it, and Eni says it was delivered less than 18 months after the contract was awarded.<\/p>\n Figures: Eni, converted to U.S. tons.<\/p>\n Eni hasn’t published how tall Douglas stands or how deep the water is right under it. It also hasn’t said which vessel installed it or what day the job wrapped up.<\/p>\n The British government’s summary of the project’s environmental statement<\/a> does cover the area as a whole. It puts the water across the project site at about 66 feet deep on average and about 115 feet at its deepest. The whole project sits inside British territorial waters off both England and Wales, so it’s within about 14 miles of the coast. The summary doesn’t break any of that out for Douglas itself.<\/p>\n So why build a new one?<\/p>\n The old Douglas complex processed gas from the surrounding fields before sending it ashore. Energy Voice, which went through the project’s environmental filings, reported that the operator first looked at converting the old processing platform, but its analysis turned up problems with stripping out the gas equipment and fitting new CO\u2082 gear in its place. The government summary confirms that Douglas CCS replaces that processing platform. Basically, building new came out ahead.<\/p>\n If you could follow a single ton of carbon dioxide from a factory, here’s roughly how the trip would go. The factory captures it and sends it through new and repurposed pipelines on land to the Point of Ayr gas terminal on the North Wales coast. From there it heads out to sea through the terminal’s old natural gas import line, which is being converted to run the other way. Douglas takes it in and passes it through more old gas lines to three smaller wellhead platforms on the Hamilton, Hamilton North and Lennox fields. Those platforms push it down into the depleted reservoirs through wells drilled off the side of the old production wells.<\/p>\n Power for all of that comes from shore, too, through two subsea cables with fiber-optic lines built in.<\/p>\n Eni says the network reuses about 93 miles of existing pipeline on land and at sea and adds about 22 miles of new pipe to reach the factories. Frankly, I’d call reusing the pipes the smartest move in the whole plan. The offshore lines are already sitting on the seabed, they already run to the right fields, and the company’s spent years pulling gas out of those reservoirs, so it knows them pretty well.<\/p>\n In case you’re picturing a giant underground cave, a gas field is basically a layer of porous rock, kind of like a hard sponge, with gas packed into its tiny holes and a tighter layer of rock on top that’s kept it sealed in for millions of years. Pump the gas out and the holes are still there under the same lid, ready to be filled with something else.<\/p>\n That’s a different trick from the Ontario nickel mine we wrote about in August<\/a>, which wants its crushed rock to soak up CO\u2082 and turn it into stone.<\/p>\n Not for a while. On May 21, Eni said it expects the Liverpool Bay system to be up and running in 2028, in step with the factories that’ll be feeding it. The October announcement doesn’t repeat that date, so that’s the most recent target I can find.<\/p>\n Once it’s running, the first phase can store nearly 5 million tons of CO\u2082 a year, and the company says that could grow to about 11 million tons a year in the 2030s. If you’d like a sense of scale, the EPA figures<\/a> a typical gas-powered car puts out a little over 5 tons of CO\u2082 a year, so the first phase alone works out to the tailpipes of close to a million cars. The government summary has the three fields taking about 120 million tons in all.<\/p>\n The first customers make cement, burn waste for energy and produce low-carbon hydrogen, according to Eni, and it’s British authorities who get to pick who plugs in after that. I’d keep an eye on that 11 million figure, since getting there depends on more factories signing up.<\/p>\n The British government has plenty riding on this, too. When the financing deal closed last year, Eni pointed to the \u00a321.7 billion the government’s committed over 25 years to its first two carbon capture clusters, this one and another in northeast England. Eni’s October announcement calls CCS “a mature and safe technological process,” which is pretty much what you’d expect the company building the thing to say.<\/p>\n As of that October 8 announcement, the whole Liverpool Bay network was about 50% built, compared with more than 30% when Eni gave that 2028 date back in May.<\/p>\n","protected":false},"excerpt":{"rendered":" Gas fields don’t last forever. Once one stops paying for itself, you plug the wells, take the platforms apart and … <\/p>\nSo what’s out there now?<\/h2>\n
The old gas pipes get a second job<\/h2>\n
When does the CO\u2082 start flowing?<\/h2>\n