Geology, geography and global energy

Scientific and Technical Journal

GEOMORPHOLOGIC CHARACTERISTIC AND STRUCTURAL HISTORY OF SALT DOMES OF THE SOUTH-WEST PRE-CASPIAN REGION

2020. №4, pp. 42-53

Ushivtseva Lyubov F. - Astrakhan State University, ushivceval@mail.ru

Nesmianova A. S. - Astrakhan State University, geologi2007@yandex.ru

Ostrikova E. E. - Astrakhan State University, geologi2007@yandex.ru

During the development of the mineral resources having active salt massifs geology along with increased man-made load on deep-seated zones of the lithosphere, the presence of salts in the cross- section contributes to a range of drilling complications. Salt of various composition present in the Peri-Caspian, the East-Kuban, the North-German, the Dniepr-Donets depressions leads to solutions, brine showings, loss of circulation, plastic displacements, and hence to drill pipes stickings and drill- stem buckling. Originality. Tectonic features and internal architecture of positive and negative salt- dome structures define the extension of objects with anomalous geology - brine-saturated formations, salts and intrasalt sticky shale solution and flowage zones. In this article, the structure of the salt-domed structures of the southwestern part of the Caspian basin, their morphological varieties are con- sidered in detail, and a classification is given according to various criteria. It has been established that the degree of intensity of salt tectogenesis and the initial thickness of salt tectogenesis and the initial thickness of the salt determined the variety of salt structures; The most active growth of salt domes occurs during the general uplift of the territory at the turn of the Late Permian - Early Triassic, Late Triassic, Early Jurassic, Oligocene-Pliocene eras. Therefore, the study of salt-bearing formations and identification (based on science approach) of the section zones with anomalous objects within their massifs (reduced rocks strength properties zones, faults, brine-saturated formations, potassium-magnesium salts, and sticky shale zones development) using outrunning forecasting is crucial. Summary . Knowledge on geological internal architecture of the section of the project well at the predesign stage, to be drilled at the pre-project stage the following to choose the adequate well design, to pick mud clay individual parameters. The article describes salt-dome structures geological aspects, characteristics, and classification as well as their connection with oil/gas presence.

Key words: salt dome tectonics, salt massif, salt-dome structures, salt-bearing formations, anomalous objects, diapir, ridge, trough, stock, oil/gas presence

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