Tengiz

…exploit the reserves of the Tengiz oil field, marking the world’s largest oil strike in two decades. Other major oil fields include Karachaganak, which began operation in the late Soviet era, and Kashagan, whose development in the early 21st century made it the largest oil field outside the Middle East.

The Tengiz field on the northeast border of the Caspian Sea is a supergiant with up to 9 billion barrels recoverable reserves. It was originally discovered in 1979; however, it was not actively developed until the American oil company Chevron gained equity in the region in…