North Sea operator Dana Petroleum has reported a successful flow test on the first well in its Western Isles development.

Another three production wells have been drilled and cased to a surface casing depth. Four subsea christmas trees also have been installed by the semisubmersible Ocean Nomad which is operating at the fields, Dana said in a project update.

Western Isles will tap two fields, Barra and Harris in the UK Northern North Sea region, with up to five production and four water injection wells tied back to an FPSO supplied by Sevan Marine with oil export via a shuttle tanker. Gas is to be exported via a 12-km (7.5-mile) pipeline to the nearby Tern platform. Western Isles, for which capex is $1.6 billion, is due onstream in the fourth-quarter 2015.