Field partner Endeavour International revealed on Friday that a valve was discovered stuck in the 'shut' position on the outlet side of the Rochelle production manifold.
It added that an attempt to open the valve manually was unsuccessful and said CNOOC was now in the process of trying to find an intervention vessel to open the valve.
The problem emerged as CNOOC attempted to restart production from the field, with the East and West development wells now fully completed and tied in to the production manifolds.
