Micropaleontological Approaches to South Caspian Oil and Gas Development
Keywords:
South Caspian Basin, Quaternary deposits, Micropaleontology, Engineering geology, Offshore oil and gasAbstract
The South Caspian Basin is among the most structurally complex and geodynamically active regions globally, characterized by rapid sedimentation, high subsidence rates, extensive overpressure zones, and frequent mud volcanism. Together with strong seismicity, these factors pose substantial engineering challenges for offshore oil and gas development. Quaternary deposits, which underpin most offshore facilities, are critical to the safe and economical design of platforms, drilling rigs, and subsea infrastructure. Yet despite extensive studies of Caspian Sea sediments, engineering–geological data on the physical and mechanical properties of Quaternary deposits in hydrocarbon-bearing areas remain insufficient.
This study integrates micropaleontological, lithological, and stratigraphic analyses of 300 core samples from 70 boreholes across 45 offshore structures to characterize the composition, distribution, and engineering relevance of Quaternary deposits. For the first time, a detailed stratigraphic subdivision based on ostracod fauna is presented, comprising five supra-horizons, ten horizons, and seven biozones defined by index species. Eleven characteristic ostracod assemblages were identified, enabling correlation of deposits across the Apsheron and Baku archipelagos and the Turkmenian sector.
Results show pronounced lateral and vertical lithologic variability, strongly controlled by depositional environment, structural setting, and post-depositional processes. Quaternary sequences include Bakuvian, Khazarian, Khvalynian, Novo Caspian, and modern sediments, with facies ranging from fine-grained clays in deep-water settings to loams and sands in nearshore and eastern shelf areas. Integrating micropaleontological data with lithostratigraphy improves geotechnical mapping and zonation, supports the prediction of overpressure zones, and reduces development risk.
These findings establish a new stratigraphic framework for the Quaternary in the South Caspian Basin and provide essential baseline data for offshore engineering, supporting safer infrastructure design, optimized field development, and risk mitigation in one of the world’s most challenging petroleum provinces.
References
Akhmedov, A. G., Javadova, A. T., & Shved, V. I. (1997). About litho dynamics of the deposits of the Upper Part of the section within the South and Middle Caspian Sea. Presentation in “Newest tectonics and its influence on the formation and distribution of oil and gas deposits” International Conference, Baku, Azerbaijan, Program of theses, pp. 24-25
Akhmedov, A. G., Shved, V. I., & Javadova, A. (1998). The newest results of completing geophysical and geotechnical data conducted within the bounds of the Caspian Sea for detailed study of the log’s upper part (LUP) sediments. Africa/Middle East 2d international geophysical conference and exhibition, Cairo, Egypt, Proceedings, p. 320-321
Azerbaijan Petroleum Industry Review (2007) Azer-Press Independent News Agency, 252 p
Dzhandzhgava, K. I., Komarov, I. S., & Neizvestnova, Ya. V. (1990). Engineering Geology of the USSR. Nedra Publishing House, Moscow, USSR, p. 240. (in Russian)
Ali, F., Shiqi, Z., Ahmad, R., Ali, B., & Iqbal, H. (2023). Palynostratigraphical and oceanic anoxic events investigation in the Lower Jurassic Black Shale, Indus Basin, Pakistan. Journal of Himalayan Earth Sciences, 56(2), 73-88.
Javadova, A., Suleymanov, A. I., & Shved, V. I. (1995). Apsheron archipelago’s Quaternary deposit map. Scientific Notes. Journal of Azerbaijan Oil Academy, 2, 37-42, (In Russian)
Javadova, A. (2023). Biostratigraphy of Quaternary deposits in the offshore South Caspian basin. Scientific Bulletin of the Azerbaijan Society of Petroleum Geologists. Printed by OJSC “Sarq Qarb”. Azerbaijan Geologist Journal. 26, 11-19.
Javadova, A. (2025). The Role of Applied Micropaleontology in Integrating Geological and Geophysical Data for the Exploration and Development of South Caspian Oil and Gas Fields. Poster presentation in the conference GEO4CHANGE, Earth, Life, Climate, Resources, Materials. Goettingen, Germany, https://www.researchgate.net/publication/395597180_The_Role_of_Applied_Micropaleontology_in_Integrating_Geological_and_Geophysical_Data_for_the_Exploration_and_Development_of_South_Caspian_Oil_and_Gas_Fields
Lebedev, L. I., Aleksina, I. A., & Kulakova, L. S. (1987). Kaspiiskoe more: Geologiia i neftegazonosnost’. Moscow: Nauka, 296 (in Russian).
Rahman, M., Ali, F., Ali, B., & Ahmad, R. (2016). Geotechnical investigation of Chitral Slates, Hindu Kush Ranges, Northern Pakistan: case study. Journal of Himalayan Earth Sciences, 49(1), 86-97.
Rzaeva, M. (2005). Patterns of formation of geotechnical properties of Quaternary deposits in the oil- and gas-bearing areas of the Caspian Sea. Candidate of Geological and Mineralogical Sciences dissertation. Moscow: USSR State Construction Committee, Production and Research Institute for Engineering Surveys in Construction. 169 pp. (In Russian).
Rahman, M., Jiang, T., Sarim, M., Hanif, M., Barrows, T. T., & Hu, Y. (2023). Late Pleistocene chronostratigraphy and biostratigraphy of Mentelle Basin and its implications for global correlation. Marine Geology, 457 (4), 107005. https://doi.org/10.1016/j.margeo.2023.107005.
Raynolds, R. G. H., Johnson, G. D., Frost, C. D., Keller, H. M., McMurtry, M. G., & Visser, C. F. (2022). Magnetic polarity maps and time maps in the eastern Potwar Plateau; Applications of magnetic polarity stratigraphy. Journal of Himalayan Earth Sciences, 55(2), 1-20. http://ojs.uop.edu.pk/jhes/article/view/1420
Shikhalibeyli, Z. S., & Grigoryan, B. V. (1983). Main features of the structure and age relationships of the basement and sedimentary cover in the South Caspian Basin. In Geological and geomorphological studies of the Caspian Sea (pp. 22–29). Moscow: Publisher Nauka. (In Russian)
Zaionchek, V.G. (1980). Laboratory studies of the properties of bottom sediments of the shelf. In: Soil Science and Engineering Geology, Issue 2. Leningrad, USSR, pp. 119–123.
