National Academy of Sciences of Azerbaijan, Baku, Azerbaijan:

I. S. Guliev, Vice-President, Professor, Doctor of Geological and Mineralogical Sciences

Azerbaijan State Oil and Industry University, Baku, Azerbaijan:

S. A. Alieva, Associate Professor, Candidate of Geological and Mineralogical Sciences

Sergo Ordzhonikidze Russian State Geological Prospecting University, Moscow, Russia:
V. Yu. Kerimov, Adviser to Rector, Head of a Chair, Professor, Doctor of Geological and Mineralogical Sciences
R. N. Mustaev, Acting Pro-Rector for Science, Candidate of Geological and Mineralogical Sciences, mustaevrn@mgri.ru

The article offers an overview of hydrocarbon systems in the North and Middle Caspian areas. In the North Caspian offshore zone, in the cross-section of sedimentary cover, there are three major levels of structural formations: subsalt (Pre-Kungurian), salt-bearing (Kungurian) and above-salt (Upper Permian–Mesozoic) structures. These structures have different geologic history and structure-forming factors, which govern the features of their formation and evolution of. In Kazakhstan’s sector of the North Caspian shelf, the large discovered oil reservoirs are the Kashagan-West and Kashagan-East fields holding, by provisional estimates, nearly 7 Bt of oil reserves and more than 3 Bm3 of gas reserves. In Russia’s sector in 1995–2006, the deposits holding more than 2 Bt of equivalent fuel reserves were discovered, namely, Filanovsky, Yuri Korchagin, Khvalyn, Sarmat and Rakushechnoe fields. Geological exploration surveys detected 10 oil and gas promising structures. In the Middle Caspian water zone, three oil reservoirs are discovered: Inchkhe-More, Sakilstoe More and Central field. The schematic maps of organic hydrocarbons in different deposits are given. The current oil and gas mining projects in the region under study are discussed. The implemented analysis of hydrocarbon systems in the North and Middle Caspian areas reveals huge recovery prospects of the Tyub-Karagan structure (388 Mt of equivalent fuel, including 324.3 Mt of oil), Atash block (248.8 Mt of equivalent fuel, including 141.7 Mt of oil), Kurmangazy structure (300 Mt to 1.2 Bt of oil resources), as well as projects as follows: Buzachi Neft (Northeast Karaturun), Zhemchuzhiny, Zhambai, Zhambyl, Satpaev, Abai, Isatai, Shagala, Makhambet, Bobek and Darkhan.

1. Boldizsár T. Terrestrial Heat Flow in the Carpathians. Journal of Geophysical Research. 1964. Vol. 69, No. 24. pp. 5269–5275.
2. Kerimov V., Rachinsky M., Mustaev R., Serikova U. Geothermal conditions of hydrocarbon formation in the South Caspian basin. Iranian Journal of Earth Sciences. 2018. Vol. 10, No. 1. pp. 78–89.
3. Washburn A. M., Hudson S. M., Selby D., Abdullayev N., Shiyanova N. Constraining the timing and depositional conditions of the Maikop formation within the Kura basin, Eastern Azerbaijan, through the application of Re-Os geochronology and chemostratigraphy. Journal of Petroleum Geology. 2019. Vol. 42, Iss. 3. pp. 281–300.
4. Aliev Ad. A., Guliev I. S., Rakhmanov R. R. Comparative analysis of mud volcanism in the Black Sea and Caspian regions. Geologiya i poleznye iskopaemye Mirovogo okeana. 2015. No. 2(40). pp. 92–105.
5. Glumov I. F., Malovitskiy Ya. P., Novikov A. A., Senin B. V. Regional geology and oil and gas content of Caspian sea. Moscow : Nedra-Biznestsentr, 2004. 342 p.
6. Mansouri Far S., Zui V. I. Geothermal field and geology of the Caspian sea region. Zhurnal Belorusskogo gosudarstvennogo universiteta. Geografiya. Geologiya. 2019. No. 1. pp. 104–118.
7. Abdullayev N. Distribution and Volume of Rocks in Sedimentary Basins – Unusual Case of the South Caspian Basin. 3^rd International Conference on Geology of the Caspian Sea and Adjacent Areas. Baku, 2019. Vol. 2019. DOI: 10.3997/2214-4609.201952003
8. Abdullayev N. A., Kadirov F., Guliyev I. S. Subsidence history and basin-fill evolution in the South Caspian Basin from geophysical mapping, flexural backstripping, forward lithospheric modelling and gravity modelling. Geological Society Special Publication. 2017. Vol. 427, No. 1. pp. 175–196.
9. Mekhtiev Sh. F., Tsaturyants A. B., Rachinskiy M. Z. Probable scheme of formation of multiplay fields and generation conditions of gas (gas condensate) and oil reservoirs. Uchenye zapiski AGU im. S. M. Kirova. Seriya geologo-geograficheskikh nauk. 1968. No. 6.
10. Osipov A., Kerimov V., Mustaev R. Peculiarities of Hydrocarbon Generation at Great Depths in the Crust. Doklady Earth Sciences. 2018. Vol. 483, No. 1. pp. 1413–1417.
11. Senin B. V., Leonchik M. I., Osherova N. A. Main results of geological exploration and growth prospects of marine hydrocarbon resource base in the Black Sea-Caspian region. Mineralnye resursy Rossii. Ekonomika i upravlenie. 2018. No. 2. pp. 7–17.
12. Serebryakova V. I., Ermolina A. V. Optimization of the complex of geological and geophysical researches at different stages of exploration works in the water area of the Caspian sea and adjacent regions. Geologiya, geografiya i globalnaya energiya. 2016. No. 4(63). pp. 24–30.
13. Guliev I. S., Kerimov V. Y., Mustaev R. N., Bondarev A. V. The Estimation of the Generation Potential of the Low Permeable Shale Strata of the Maikop Caucasian Series. SOCAR Proceedings. 2018. No. 1. pp. 4–20.