Chevron expects Kazakhstan's Tengiz oil field, one of the largest of its kind in the world, to produce 1 million barrels of oil equivalent per day.

The energy giant is spending nearly $50 billion to expand the Tengiz oil field, allowing it to pump one million barrels a day.

Chevron said on Friday it had started production at a $48 billion expansion of the giant Tengiz oilfield which will bring its output to around 1% of global crude supply.