Published February 2015

Geodynamics as a reflection of hydrocarbon potential of deep structures in the South Caspian basin

E.Yu.Pogorelova

The South Caspian Basin (SCB) is the largest sedimentary basin, which occupies the south deep part of Caspian Sea and joining to it West Turkmenian from the east and Lower Kura depressions from the west. The northern boundary of SCB is the Apsheron step (subduction zone), formed due to the collision of Iranian-Afgani micro-continent and Eurasian plate. The southern and western boundaries of the SCB (microplates) are characterized by high seismic and young Neogene-Quaternary volcanism. At sea, the largest oil and gas fields tend to southern anticline line Apsheron-Balkhan anticline zone and Baku archipelago, on the land of Azerbaijan the most significant concentration of primary resources are concentrated on the Apsheron Peninsula. A characteristic feature of the South Caspian region is a sharp change from a longitudinal into folded structures of the Caucasus, Kopetdagh and the Apsheron step to the cross-over within the southern part of the basin. This phenomenon owes its origin to the horizontal movement of the blocks on the flanks that are limited by shifts. Fundamental oil and gas resources of the region are associated with red-colored Productive Series of Lower Pliocene. Paleogene-Miocene and Mesozoic sediments in the waters of South Caspian are connected with the most elevated tectonic zone of North Apsheron. By the analogy with Shahdeniz and Umid gas-condensate fields, it can be expected to discover predominantly gas-condensate fields in depths over 5 km in South Caspian Basin. The crystalline basement of the SCB is divided into blocks (covered with thick sedimentary layer) with deep faults, which are the migration routes for hydrocarbons. It is advisable to look at the near-fault structures as the sedimentary cover and the crystalline basement.