Tengiz field (, Teñız mūnai ken orny) is an oil field located in Zhylyoi District, Atyrau Region, northwestern Kazakhstan. Geography The oil field is located in an area of low-lying wetlands along the northeast shores of the Caspian Sea. It covers a project license area which also includes a smaller Korolev field as well as several exploratory prospects. Sizewise, Tengiz reservoir is wide and long. Discovered in 1979, Tengiz oil field is one of the largest discoveries in recent history. The city of Atyrau, north of Tengiz, is the main transport hub of Tengiz oil. Many nations are involved in a large geopolitical competition to secure access to this source of oil. History The Tengiz field, first discovered in 1979, has recoverable reserves estimated at between six billion and nine billion barrels. The field was jointly developed in 1993 as a 40-year venture between Chevron Texaco (50%), KazMunayGas (20%), US ExxonMobil (25%) and LukArco (5%). The joint venture company is known as Tengizchevroil (TCO). Chevron is the operator of the TCO field. The Tengiz oil fields entered a new phase of production with the construction of its Second Generation Project (SGP) and the introduction of sour gas injection (SGI). This onshore development, which has been in the planning and approval stage since 2002, began in 2004 and required a total investment of $7.4bn. The integrated project was completed in the second half of 2008. Prior to its expansion in 2008, the Tengiz oilfield had 53 wells, tapping a column of crude oil around 1.6km thick. When the field was first tapped its oil pressure was 12,000psi, but in 2004 the pressure came down to 10,000psi in most areas and 8,500psi in others. The SGI project used gas injection technology to boost the pressure and increase oil recovery, while the SGP increased the number of producers (wells) and improved and expanded the crude export infrastructure. The Tengiz field’s production of crude in 2004 was 13 million tonnes per year but the SGI and SGP production increased this to over 25 million tonnes. TCO crude oil production capacity was increased by about 80% to 540,000 barrels of crude oil, 46,000 barrels of natural gas liquids and 760 million cubic feet of natural gas. The two projects created over 7,000 jobs in Kazakhstan and aided the development of the economy. A total investment of $20bn is envisaged for the duration of the 40