Serica Boosts North Sea Portfolio with Spirit Energy Assets Purchase
December 16, 2025
Britain’s Serica Energy has agreed to acquire a portfolio of Southern North Sea gas assets from Spirit Energy and affiliates for $74 million, expanding its U.K. upstream footprint and lifting reserves and production.
The deal, signed through two subsidiaries acquired following Serica’s Prax Upstream transaction, has an effective economic date of January 1, 2025, with completion expected in the second half of 2026.
The acquisition includes a 15% non-operated interest in the Cygnus gas field, one of the UK Continental Shelf’s largest producing gas assets.
Cygnus field, operated by Ithaca Energy which owns the remaining 85%, is a mid-life field, having started production in 2016. There are 11 wells, which produced a total of 4,000 boepd net to the acquired Spirit Energy stake in the first half of 2025, with an infill drilling campaign ongoing.
The first of the four firm wells in the campaign is now on production, and the second well underway. Two further wells are set to follow, with the potential for further development drilling beyond the currently approved wells.
Aside from Cygnus, Serica will acquire a 25% non-operated stake in Clipper South, and operated interests across assets in the Greater Markham Area.
As part of the transaction, Serica will also take control of stakes in the Eris and Ceres gas fields and a non-operated interest in Galleon. Following completion, the seller will retain decommissioning liabilities on the operated assets, expected to account for more than 75% of total estimated decommissioning costs.
Serica said the transaction is expected to add more than 15% to its reserves and significantly increase production, while requiring only modest upfront cash outflow.
“This transaction is a further step towards delivering on our strategy and diversifying our asset base through the addition of high-quality assets, adding over 15% to our reserves and significantly boosting production. These are also assets I personally know well, and the Cygnus field in particular is an attractive addition to our portfolio given its high uptime, low emissions, and low operating costs.
“There is also the potential for further infill drilling opportunities across the portfolio, most significantly at Cygnus, where drilling is ongoing. The transaction will require only modest cash outflow on completion and is set to generate material cash flows, while also limiting our exposure to future decommissioning costs, enhancing Serica’s ability to create further value for shareholders through investing in growth and delivering attractive cash returns,” said Chris Cox, Serica's CEO.
