Abstract: Pricaspian Depression - The Unique Oil & Gas-Bearing Basin of the World

A. A. Abdulin, S. Zh. Daukeev, E. S. Votsalevsky

The Pricaspian depression is a unique oil and gas-bearing basin. The total sedimentary rock volume in the basin is about 8 million cu km. More than 100 oil and gas fields have been discovered in the basin including extremely large fields, such as Tengiz, Astrakhan, and Karachaganak.

The basin is filled with Devonian to Neogene sediments, a very wide range in age for a single sedimentary basin. The range in age and composition of the rocks results in complex geology, complex conditions for producing oil and gas, and complex phase states of the hydrocarbons present.

The basin fill comprises the Paleozoic section below the Kungurian salt, the Kungurian and Kungurian to Permian salt-bearing section, and the upper Permian to Paleogene and Neogene sedimentary complexes above the salt. The thick sedimentary succession and specific oil and gas productivity are what make the Pricaspian basin a unique sedimentary basin.

The geologic structure and basin evolution during the Paleozoic, details of sedimentation in the Devonian to Early Permian, initial salt deposition and the dynamic evolution of salt domes, hydrocarbon generation and accumulation zones, various trap types, field types, hydrodynamic regimes, and hydrochemical content of groundwater are discussed in the paper.

AAPG Search and Discovery Article #90956©1995 AAPG International Convention and Exposition Meeting, Nice, France