The Piper oilfield is a substantial North Sea oilfield covering 30.1 km². It lies roughly half way between Aberdeen and Bergen, at the eastern end of the Moray Firth basin". Oil extracted from it is piped to Scotland, where it is refined at a refinery on the island of Flotta, in the Orkney Islands, while gas is shipped via the Frigg gas pipeline. In June 1975, the Piper Alpha oil platform was placed over the field in 144 m of water, secured in place by 24 piles extending 116 m beneath the seabed. The platform was designed for simultaneous drilling and production. Piper Alpha was the site of one of the world's worst oil platform disasters when it was destroyed by an explosion in 1988, with the loss of 167 lives.