Equinor Energy AS has been granted a drilling permit by the Norwegian Petroleum Directorate to prove sandstone and storage potential for CO2 in the Cook and Johansen formations covered by exploitation license 001 (Aurora) in the Norwegian North Sea. Sealing properties of the overlying Dunlin shale will also be examined.
Well 31/5-7 E—the first well to be drilled in the first exploitation license on the Norwegian shelf—will be drilled about 17.5 km southwest of Troll A from Seadrill’s West Hercules semisubmersible drilling rig after it concludes drilling well 6611/1-1 in the Norwegian Sea (OGJ Online, Nov. 26, 2019). The area in this license consists of parts of Block 31/5. If the well proves sandstone with good flow properties and a decision is subsequently made to use the formations for CO2 storage, the first CO2 injector will be drilled as a sidetrack from the wildcat well.
The Johansen Formation is situated at a depth of around 2,700 m in the relevant area, said NPD exploration assistant director Wenche Tjelta Johansen. The Troll reservoir lies some 600 m higher in the stratigraphic sequence, and there are many tight layers of shale between the reservoir and the Johansen formation, NPD said. The tight shale layers must be investigated to be certain the CO2 will remain in place, she said.
Equinor is operator of the license with 100% interest. As part of the Northern Lights project, Equinor and partners Shell and Total are performing engineering for a CO2 storage facility as part of a full-scale demonstration project for carbon capture and storage (CCS). The partnership is expected to submit a plan for development and operation (PDO/PIO) in the spring of 2020. Given a positive final investment decision by the Norwegian government and project partners in 2020, the project is scheduled to be operational in fourth-quarter 2023 and could store 1.5 million tonnes of CO2 every year for 25 years.
Since 1996, CO2 has been removed from Sleipner Vest gas and injected in the Utsira formation. One million tonnes of CO2 are stored in the subsurface every year. Also, since 2007, 700,000 tonnes/year of CO2 has been stored at Snøhvit field. It is separated from the gas at the facility on Melkøya and sent by pipeline into a reservoir that lies 140 km from land.
NPD estimates the reservoir volume on the Norwegian shelf could accommodate more than 80 billion tonnes of CO2.