Denmark reverses the direction of an oil rig for bulk carbon storage
Denmark is moving forward with Project Greensands, an initiative that will take huge quantities of captured carbon out to an oil rig in the North Sea, and pump it down to sequester it in the sandstone formations that once held oil and gas.
After being awarded the largest single grant in Danish history last December – some €26 million (US$27 million) – project leader Ineos Energy has tapped UK engineering consultancy Kent to "conduct screening studies covering the CCS Value Chain from the onshore capture sites, liquefaction, onshore storage, transportation, and offshore sequestration."
It's a remarkable project, for sure. Greensands will repurpose the Nini A oil platform, some 200 km (120 miles) off the cost of Denmark in the North Sea, reversing its previous flow to pump liquefied CO2 some 1,800 m (1.1 miles) below the sea bed. Here it will begin refilling the Paleocene sandstone reservoir known as the Siri Field, which has done a fine job containing oil and gas for the last 20 million years, and which has been identified as an excellent spot for carbon sequestration.
Denmark plans to begin sequestering carbon here at a rate of 1.5 million tons a year by 2025, rising to 8 million tons a year by 2030. The latter figure represents more than 13% of the country's current known emissions. Annoyingly, it'll have to get there by ship, so until carbon-neutral shipping is sorted out, that part of the process will still be dirty.
The project website claims there's enough space in this single reservoir to store all the carbon Denmark has ever created in its history, and then some. Indeed, it says there's enough sequestration potential in the Danish subsoil to stow 500 year's worth of emissions at today's rate.
Why go out so far to sea and cause yourself all the trouble of sending tankers on 400-km (240-mile) round trips all day long? Presumably because there's already a nice big hole, pipes and an oil rig sitting there ready to go.