Venture Production, the Aberdeen oil and gas operator, said yesterday it now believed the Cygnus discovery would prove to be one of the UK’s largest remaining undeveloped gas fields.
Field partner Endeavour Energy UK said it estimated that recoverable reserves from the eastern part of the field alone could be more than 500billion cubic feet (83.33million barrels of oil equivalent) and this number was expected to increase.
Endeavour added that it believed Cygnus would be one of the largest gas fields to be discovered in the UK southern North Sea in the past decade.
Venture said it had completed appraisal of the eastern part of Cygnus by drilling a well which materially increased potential recoverable reserves from the field.
It said the latest well had tested at a rate of 32million cu ft of gas per day, significantly better than the 5-10million anticipated before drilling. Venture chief executive Mike Wagstaff said: “The Cygnus partnership is well placed to move this field rapidly into development and the large working interest that Venture acquired in two deals last year now forms an exciting part of our developing business.”
The company, which has a 48.75% interest in GDF Suez-operated Cygnus, said the southern North Sea field had up to five potential productive zones.
A draft field-development plan has been prepared which envisages a phased development of the eastern part of the field, which lies within blocks 44/12a and 44/11a near the Caister Murdoch gas export hub.
Venture said that in due course further appraisal drilling may be carried out in the western part of the field, which could lead to additional recoverable reserves through further development phases.
GDF Suez has a 38.75% stake in Cygnus and Endeavour Energy UK has 12.5%.
Venture acquired a 35% stake from Tullow Oil a year ago and a further 13.75% was acquired from E.ON Ruhrgas last October.
Shares in Venture closed down a penny at 804p.