In the spring of 2018, Equinor was awarded a licence to drill an exploration well in the southern part of the Smeaheia area. The subsequent drilling on the Gladsheim structure during 2019, represented a rare opportunity to collect subsurface data, paving the way for a future CO₂ repository. SWAP (Strategic Well Acquisition Project), supported financially by CLIMIT, was established in 2019 in order to gather data that operators usually do not collect when drilling exploration wells. 

«The idea was that even if the well turned out to be dry, it would still be important to extract extensive data from the subsurface, since the area is a prospective CO₂ storage location, explains Equinor’s Rune Thorsen, project manager for SWAP.

Comprehensive scope

A large part of the extra collection consisted of data from the cap rock. The data confirmed that the cap rock is strong and will remain impermeable if CO₂ should be injected into the reservoir. Core samples were taken and rock-mechanical tests executed in order to find the quality and strength of the cap rock. Equinor also measured the porosity, permeability and fracture pressure of the rock in a thick shale, the Draupne formation. Usually, these types of samples of the cap rock are not taken in an exploration well.

In addition, a set of pressure measurements were conducted in the different reservoirs, in order to measure the degree of communication with the Troll field.

And the analyses yielded positive results

«It was confirmed that the reservoirs are well suited for CO₂ sequestration. There is ample communication with the Troll field, and core samples extracted in the Gladsheim well confirms that the strength of the cap rock is good. This means that we can inject very large volumes of CO₂,» says Thorsen.

In the SWAP 2 project, extra data was captured from another exploration drilling, this time at Stovegolvet, in the southern part of the Horda platform.

«When we exploration drill on the Horda platform around Troll, the chances of finding commercial quantities of hydrocarbons typically lie between 20–30 percent. But our long experience and understanding of the area tell us that the geology can safely retain CO₂. If we collect comprehensive amounts of data during exploration drilling, we can avoid injecting only small volumes of CO₂ initiallybefore ramping up volumes after several years of injection experience. Retrieving data during exploration drilling enables us to scale up volumes faster,» explains Thorsen.

A step closer to realization

And these are exciting times for the CCS community. In June 2021, Equinor nominated Smeaheia for licensing by the Norwegian Ministry of Petroleum and Energy. In September, the licensing round for the next significant areas for CO₂ storage on the Norwegian Continental Shelf, was opened. And Equinor was one of the five companies that submitted bids.

«At Smeaheia, we have proposed developing a storage solution for 20 million tonnes of CO₂ per year. This represents a formidable and necessary increase in global CO₂ injection capacity and should be regarded as an explicit benefits realisation of the pioneering Norwegian Longship project » says Thorsen.

Equinor has ambitious plans to stay ahead as one of the global leaders in the field of CCS.

«We hope that we will be awarded the licence on Smeaheia, and that the second well at Stovegolvet can open up for further CO₂ storage licenses in the area. I believe that the entire Horda platform – which includes the current Northern Lights licence, Stovegolvet, Smeaheia and the surrounding region – has the potential to become a huge central deposit area for CO₂ on the NCS.»

Financial support from CLIMIT represented an important contribution to the project

«CLIMIT awarded financial support that made it possible to execute SWAP and SWAP 2. Without this support and results from drilling, CO₂ sequestration on Smeaheia would probably have been delayed by several years,» says Rune Thorsen.

Partners in SWAP were Equinor and licence partners in PL921: Lundin Norge, Petoro and DNO Norge AS. Partners in SWAP2 were Equinor and license partner in PL785S, TotalEnergies.