Jackdaw downstream emissions to top 23m t CO2e, Shell confirms

GAS EXTRACTED from the Jackdaw gas field in the UK North Sea will be responsible for over 23m tCO2e of emissions over its 11-year lifetime, developer Shell has confirmed.

In an updated environmental impact assessment (EIA) published last week, Shell said that combustion of natural gas produced at Jackdaw will release around 20m tCO2e. This is on top of around 3.6m tCO2e in well-to-tank emissions from production. Under the maximum production scenario, total emissions could reach 35.8m tCO2e.

Shell says the emissions “are not considered to have a likely significant effect” on efforts to limit global warming to 1.5C, as per definitions set by the Institute of Sustainability & Environmental Professionals. Shell calculated that Jackdaw-related emissions will contribute 1.89% of the UK’s “nationally determined contribution” set by the seventh carbon budget in February this year.  

The publication of the expanded EIA follows a court ruling in January that the project could not receive final approval without consideration of downstream emissions. Shell’s updated report follows similar action by Equinor for the Rosebank development.

Shell expects likely production will peak at 373m t/y of gas condensate in 2027 – equivalent to the amount of energy to heat 1.4m homes – contributing around 6.5% of UK domestic gas output. The project involves a not-permanently-attended wellhead platform located around 250 km from Aberdeen.

Although the project is similar in relative scale to Rosebank, which will supply about 8% of UK domestic oil, its emissions will be far lower than Rosebank’s projected 250m tCO2e over 25 years. Jackdaw’s emissions intensity is also lower: 8.5 kgCO2e/boe compared with Rosebank’s 12 kgCO2e/boe.

Most of the gas produced from Jackdaw will be consumed in the UK. Shell said that, despite falling demand for fossil fuels, North Sea Transition Authority projections show the UK will still need to import an average of 31m t/y of oil equivalent over the next decade. Shell argued that Jackdaw “can contribute to ongoing UK demand whilst emitting lower emissions from comparable UK offshore production and significantly less than comparable imported LNG production”, pointing to emissions of 85 kgCO2e/boe for imported LNG and an average of 18 kgCO2e/boe across existing UK upstream operations.

However, Greenpeace UK co-executive director Areeba Hamid described Jackdaw as a “dud project”, claiming it “will fuel more extreme weather…leaving ordinary people to pick up the bill”. She added: “It’s decision time for ministers. If they approve Jackdaw, it’ll be Shell’s profit, our loss.”

Uncertainty in Fife

Shell says the Jackdaw project is already 90% complete and that it has drilled four high pressure/high temperature wells and laid a 31 km pipeline to the Shearwater platform where the gas will be processed. Modifications to Shearwater are ongoing and Shell expects first production at Jackdaw to begin in the second half of 2026.

While most of the natural gas produced at Jackdaw will be transmitted through national gas pipelines, some will be processed and separated at the company’s natural gas liquids plant in Mossmorran in Fife, Scotland. Shell originally planned to supply ethane to a neighbouring ethylene plant operated by ExxonMobil, but these plans have been thrown into doubt by Exxon’s announcement last week that the plant will close by February 2026.

Shell has not confirmed how its plans will change in response to ExxonMobil’s decision.