Lithological and facial features of organogenic structures of the second carbonate stratum of the eastern flang of the Pre-Caspian depression on Zharkamys uplift

Abstract

The Pre-Caspian Basin is the major oil and gas basin in Kazakhstan. It contains huge hydrocarbon reserves within pre-salt carbonate deposits. There had been numerous discoveries of oil and gas-condensate fields associated with pre-salt carbonate complexes in the Eastern part of the Caspian Basin. The object of this study is the second carbonate stratum (CS-II) of the Late Visean Early Moskovian age of the Eastern part of the Pre-Caspian Basin. The formation of the Eastern part of the Pre-Caspian Basin took place in the zone of the junction of the East European craton and folded structures of the Urals. These conditions predetermined the complexity of sedimentation processes, variety of lithological types of rocks and diagenesis processes with the formation of reservoir heterogeneity. CS-II will retain the leading role as the main reservoir of hydrocarbons and it has further potential for oil exploration in the region for two to three decades. It has been proven by the discovery of large oil and gas-condensate fields in the CS-II, such as Zhanazhol, Urikhtau, Kozhasai, Alibekmola, etc.