Partners in the Northern Lights project will drill an exploration well south of the Troll field in the North Sea with the objective to not find oil and gas.
Wildcat well 31/5-7 Eos is being drilled to investigate whether the reservoir in the deep Johansen Formation is suitable for storage of carbon dioxide (CO2).
The Northern Lights project, being led by operator Equinor with partners Shell and Total, will use the West Hercules drilling rig to drill the first well in exploration license 001, and the objective is to prove sandstone and the storage potential for CO2 in the Cook and Johansen geological formations, the Norwegian Petroleum Directorate (NPD) said. The companies will also examine the sealing properties of the overlying Dunlin shale.
If the well indicates good reservoir 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, NPD said.
“If the well proves sandstone with good flow properties, this part of the Johansen Formation may be well-suited as a storage facility for CO2,” said Assistant director exploration Wenche Tjelta Johansen.
She said that the Johansen Formation is situated at a depth of around 2,700 meters in the relevant area, and that the wells previously been drilled down into the formation are located on the Troll field, far from this well location.
The Troll reservoir is situated around 600 meters higher up in the stratigraphic sequence, and there are many tight layers of shale between the reservoir and the Johansen Formation. It’s important to investigate the tight shale layers in order to be certain that the CO2 will remain in place, NPD said.
“In Norway, we have lots of experience and good expertise when it comes to safe storage of CO2 under the seabed,” Johansen said.
Since 1996, CO2 has been removed from the Sleipner Vest gas and injected in the Utsira Formation. One million metric tons of CO2 are stored in the subsurface every year. Since 2007, 700,000 metric tons of CO2 per year has also been stored at the Snøhvit field. It is separated from the gas in the process facility on Melkøya before it is sent by pipeline down into a reservoir located around 140 kilometers from land. Regular surveys are performed to monitor how injected CO2 fills the storage area.
The NPD has mapped areas that may be suitable for safe, long-term storage, an endeavor which resulted in a CO2 storage atlas for the Norwegian shelf. Estimates showed that, in theory, the reservoir volume on the shelf could accommodate more than 80 billion metric tons of CO2, which is equivalent 1,000 years of Norwegian CO2 emissions at the current level.
The Northern Lights drilling is part of the Norwegian full-scale project for capture, transport and storage of CO2 (CCS). This project includes capture of CO2 from two industrial firms in Eastern Norway, as well as transport of liquid CO2 to a terminal in Western Norway. From there, the liquid CO2 will be transported via pipeline and pumped into a reservoir at a depth of nearly 3000 meters under the North Sea where it will be permanently stored.
The full-scale project is a result of the authorities’ ambition to demonstrate a full-scale value chain for CCS in Norway by 2024.
Since the objective of this well is to store CO2, it is being drilled according to the CCS regulations for transport and storage of CO2. The NPD has been involved in the preparations for the drilling.
“We have performed a lot of technical work in connection with the storage project, and we have had regular meetings with the operator,” Johansen said.
The authorities gave Equinor and its partners an exploitation licence for storage of CO2 in January this year. According to the plan, Northern Lights will submit a Plan for development and operation (PDO/PIO) in the spring.
If the development plan gets a green light, Northern Lights has made a commitment to store 1.5 million metric tons of CO2 for the authorities, every year for 25 years.