Reservoir Characteristics and Sedimentary Evolution of a Major Pre-Caspian Field: The Example of Karachaganak

Karachaganak Field in northwestern Kazakhstan is a giant gas condensate reservoir underlain by<br>an oil rim with a compositional gradient from top to bottom. The Lower Permian to Upper<br>Devonian carbonate reservoir contains 1.236 billion tonnes of liquids and 1.371 trillion cubic<br>metres of gas in place (17.78 billion barrels of oil equivalent). The field was discovered by<br>Uralskneftegasgeologia in 1979, and first produced by KarachaganakGazprom in 1984. In<br>November 1997, an international consortium comprising ENI-Agip, BG Group, Texaco and<br>Lukoil signed a Production Sharing Agreement (PSA) with the Republic of Kazakhstan to<br>optimise the technical and economical recoveries.