/ license to work in the site. The TengizChevroil (TCO) joint venture has developed the Tengiz field since 1993. The major partners in TengizChevroil are Chevron (50% ownership), ExxonMobil (25% ownership), the Kazakhstani government through KazMunayGas (20% ownership) and Russian LukArco (5%). Every morning at about 05:00 hours you wake up,