Project Profile
Value: US$200 million
Location: Central North Sea, UK Sector, Block 23/21, 23/16f
Start-up Year: Summer 2015
Upstream condensate reserves: 18 million boe
Water Depth: 85m
Upstream Gas Reserves: 80 billion ft³
Block 23/16f covers an area of approximately 52 square kilometres in the Central North Sea and was awarded to Serica and its partners in 2005 in the 23rd Round of UK Offshore Licensing. This block forms part of Serica’s strategy to exploit modern 3D seismic processing techniques, particularly in the Tertiary reservoirs of the Central North Sea, with the aim of increasing the chances of exploration success. To test this technology, in late 2006 Serica drilled the Columbus discovery well 23/16f-11 to a depth of 10,116 feet subsea and encountered a gross gas column of 125 feet in the Paleocene Forties sands. The well was tested and, during the main five-hour flow period on a restricted choke of 56/64”, produced at a stabilised average rate of 17.5 million scfd and 1,060 bpd of 47.5° API condensate with a wellhead pressure of 1,200 psi. The well was suspended for potential use in the development of the Columbus field.
In 2007 Well 23/16f-12 was drilled as a vertical appraisal well approximately three kilometres north of the Columbus discovery well, and encountered gas/condensate-bearing Paleocene sands at a higher elevation than those tested in well 23/16f-11. A full evaluation of the hydrocarbon-bearing interval was carried out and reservoir fluid samples were obtained. To further evaluate the Columbus discovery, the 23/16f-12 well was then sidetracked (as 23/16f-12z) to a bottom-hole location approximately two kilometres north of the Columbus discovery well and encountered gas/condensate-bearing Paleocene sands similar to those found in 23/16f-11. Reservoir fluid samples were obtained and the well was suspended for potential use in the development of Columbus.
In December 2008, BG International (BG) drilled an appraisal well (23/21-7) in the northern part of Block 23/21, immediately to the south of Block 23/16f. The well comprised a total of four penetrations of the Forties sand reservoir, two of which encountered gas bearing sands with pressures similar to that found in the Columbus field. Serica is currently working with BG to finalise plans to export Columbus production via BG\'s Lomond platform. In 2015, BG Group and SSE E&P have decided to sell their respective stakes in the block. Following completion of the transaction, the Columbus Participants own 100% of the Columbus field with Serica having a 50% interest and continuing as field operator, while Endeavour and EOG each will have 25% interest.
Operators:
Serica Energy: Operator with 50% interest
Endeavour Energy: 25% interest
EOG Resources: 25% interest
Contractors:
Netherland Sewell & Associates: Resource estimation