ABERDEEN, UK -- GDF Suez has achieved further drilling success with its second appraisal well in the southwestern part of the Cygnus gas field in the UK southern North Sea.
Well 44/12a-5 delivered a stabilized flow of 29 MMcf/d of gas from 94 ft (28 m) of perforations in the Leman interval, confirming good reservoir characteristics. It also completed the full appraisal of the field within its currently determined boundary, following the first western area well (44/11a-4) which was drilled in March.
GDF Suez will use analysis from the Cygnus discovery wells, the six appraisal wells, and 3D seismic evaluation to assess reserves for the full field development planning.
Following last year’s appraisal of Cygnus’ eastern area, the operators and its partners Centrica and Endeavour Energy are pursuing a revised scheme. This features an enlarged first phase, taking in full development of the eastern area, due onstream in 2013, and a second phase development of the western area. GDF Suez is aiming for project sanction in 2011.
The partners also have been awarded exploration licence P1731 which surrounds Cygnus. This contains prospective un-drilled fault blocks which will likely prove a further extension to the field.
GDF Suez’s latest analysis suggests Cygnus contains 500 bcf to 1 tcf recoverable natural gas.
Centrica Energy Upstream Managing Director Jonathan Roger said: "This is potentially one of the most significant undeveloped gas fields in the UK continental shelf and comes at a time when developing the untapped potential of the North Sea is critical to UK energy supply security."
Cygnus is a large, multi-fault block accumulation discovered in 1988. It extends across blocks 44/12a and 44/11a, 15 km (9.3 mi) west of the Tyne field.
Cygnus partners opt for two-phase development
GDF Suez has achieved further drilling success with its second appraisal well in the southwestern part of the Cygnus gas field in the UK southern North Sea.