abstract:Tengizchevroil is a joint venture between Chevron (50% share in the consortium), ExxonMobil (25% share), KazMunayGas (20% share) and LukArco (5% share). The joint venture was formed in April 1993, when the Kazakh government granted an exclusive 40-year right to Tengizchevroil (TCO) to develop the Tengiz and Korolevskoye oil fields located in the north-eastern reaches of the Caspian Sea in Kazakhstan.