Eleven of the world's biggest oil firms are turning the taps on the Baku-Tbilisi-Ceyhan (BTC) pipeline, which will pump a million barrels a day of Caspian oil to world markets.

Many hopes are pinned on the Caspian, and the $4bn BTC is the biggest step so far in its development. But does it have the potential to satisfy the world's thirst for oil?