IOG is 50% owner and operator of three fields in four licences in the UK sector of the Southern North Sea collectively known as the Vulcan Satellites. The remaining 50% interests are held by CalEnergy Resources Limited.  

Field Licence(s) Block(s)
Nailsworth P130 & P2342 48/25b & 48/25a
Elland P039 49/21a
Southwark P1915 49/21c


Field Management Estimate Net Gas Reserves (Bcfe)
Nailsworth 48
Elland 26
Southwark 47


Nailsworth was discovered by Shell/Exxon in 1987. Two further appraisal wells were drilled in 1989-90 and a further well was drilled by Century Exploration in 2009.


The fields lie approximately 30-45km east of our Blythe Hub and are ready for development with no further appraisal required.

The Field Development Plan was originally submitted in Q4 2017 for development via a number of horizontal hydraulically stimulated wells. These are to be drilled from Normally Unmanned Installations. During development engineering studies in 2018 it was decided to include Southwark as part of a Phase 1 development comprising Blythe, Elgood and Southwark and the Field Development Plan was amended accordingly

The Environmental Impact Assessment for the Southwark field, which is part of the Phase 1 development, was submitted in August 2019

First gas from Southwark is scheduled for July 2021.

Blythe Hub Environmental Impact Assessment Addendum– Southwark Field