Eni drills landmark appraisal well to power UK’s carbon storage momentum

The NSTA estimates that around 100 stores will need to be appraised to identify the most suitable candidates for carbon storage

Eni is drilling the first carbon storage appraisal well on the Hewett field in the Southern North Sea, marking a major step forward for the Bacton Carbon Capture and Storage (CCS) project. 

Operated by global energy company Eni, the well represents an important advancement in assessing the carbon storage potential of the UK Continental Shelf (UKCS), which has an estimated capacity of up to 78 gigatonnes in depleted reservoirs and saline aquifers—enough to store all the CO₂ emitted in the UK since the industrial revolution. 

The NSTA estimates that around 100 stores will need to be appraised to identify the most suitable candidates for carbon storage, supporting the UK’s ambition to achieve net zero emissions by 2050. 

Located 18 miles off the Norfolk coast, the Hewett field was one of the UKCS’s longest-serving gas fields. Production began in 1969 under Phillips Petroleum, making it the third field in the North Sea to come onstream after West Sole and Leman. By the time of its decommissioning in 2023, Hewett had produced 3.5 trillion cubic feet of gas. 

Now, Eni aims to give Hewett a new lease of life as a carbon storage hub underpinning the Bacton CCS project. The field is believed to have the capacity to store up to 10 million tonnes of CO₂ per year, offering decarbonisation solutions for emitters in the Bacton and wider Thames Estuary region, as well as potential cross-border benefits for European industries. 

This achievement highlights the UK’s accelerating progress toward becoming a global leader in carbon capture and storage—an emerging industry expected to support over 50,000 skilled jobs in the long term. 

The NSTA has already awarded permits for two major CCS projects: the Northern Endurance Partnership in December 2024 and Liverpool Bay CCS, also operated by Eni, in April 2025. Together, these projects could store more than 200 million tonnes of CO₂, equivalent to removing 110 million cars from the road for one year. The permits have also unlocked £6 billion in supply chain contracts and created 4,000 construction jobs. 

In May 2025, the NSTA called for nominations for additional carbon storage locations to encourage applications focused on technically mature areas, thereby reducing time to project delivery. To date, 21 licences have been awarded under the UK’s inaugural carbon storage licensing round, which concluded in September 2023. Licence CS008, covering the Hewett field, is held by Bacton CCS Limited, a subsidiary of Eni CCUS Holding. 

The appraisal well on Hewett also marks the first consented carbon storage appraisal well under the NSTA’s Well Operations Notifications System (WONS).