Kazakhstan journal for oil & gas industryKazakhstan journal for oil & gas industry2707-42262957-806XKMG Engineering10897810.54859/kjogi108978Structural-sedimentological features of Triassic deposits of the Uaz Severny field and their representation in the digital geological modelMendigaliyevAibeka.mendigaliyev@kmge.kzhttps://orcid.org/0009-0009-0379-468XSabirovaAiniyeta.sabirova@kmge.kzhttps://orcid.org/0009-0001-6894-8303AldebekAlmiraa.aldebek@kmge.kzhttps://orcid.org/0009-0004-2233-4412MurzagaliyevaZhansayazh.murzagaliyeva@kmge.kzhttps://orcid.org/0000-0002-2657-8324MardanovAltynbeka.mardanov@kmge.kzhttps://orcid.org/0000-0002-8342-3046Atyrau branch of KMG EngineeringAtyrau Branch of KMG Engineering843004202619102026Copyright © , Mendigaliyev A., Sabirova A., Aldebek A., Murzagaliyeva Z., Mardanov A.<p style="text-align: justify;"><strong>Background.</strong> Triassic deposits in the southeastern part of the Precaspian Basin, formed under the influence of salt tectonics, are characterized by significant lithological heterogeneity and variability of reservoir properties, which requires a comprehensive analysis of the factors controlling their hydrocarbon potential.</p> <p style="text-align: justify;"><strong>Objective.</strong> To analyze the impact of structural and sedimentary factors on the formation of Triassic reservoirs of the Uaz Severny field and to substantiate their structural-sedimentary characteristics.</p> <p style="text-align: justify;"><strong>Materials and methods.</strong> The study is based on seismic data, well logging (WL) data, core analysis and 3D geological modeling using seismic attributes (RMS, AI) as trends.</p> <p style="text-align: justify;"><strong>Results.</strong> A comprehensive analysis of the data showed that productive horizons are represented by lens-shaped sand bodies with pronounced lateral variability. It was established that hydrocarbon-saturated zones do not always coincide with structural highs and are controlled by reservoir distribution. The geological model confirmed significant facies heterogeneity and complex spatial distribution of reservoir properties.</p> <p style="text-align: justify;"><strong>Conclusion.</strong> The Triassic deposits of the Uaz Severny field belong to the structural-sedimentary type. Hydrocarbon accumulation is controlled by the combined influence of tectonic processes and sedimentary factors. The obtained results can be used for forecasting hydrocarbon potential and refining the geological model.</p>structural-sedimentary traps, Triassic deposits, porosity, salt dome, gamma-ray logging, reservoirs, lithological heterogeneity, Precaspian basin, over-salt complex, geological model.құрылымдық-седиментациялық тұтқыш, триас шөгінділері, кеуек, тұз күмбезі, коллекторлар, литологиялық әркелкілік, Каспий маңы ойпаты.структурно-седиментационные ловушки, триасовые отложения, пористость, соляной купол, гамма-каротаж, коллекторы, литологическая неоднородность, Прикаспийская впадина, надсолевые отложения, геологическая модель.1.1. Mendigaliyev A.R., Abylkhairov A.I., Amaniyazov A.A. Podschet zapasov nefti i gaza mestorozhdeniya Uaz Severnyy Atyrauskoy oblasti Respubliki Kazakhstan. [Estimation of oil and gas reserves of the Uaz Severny field, Atyrau region, Republic of Kazakhstan]. Atyrau: Atyrau branch of LLP “KMG Engineering”, 2021.2.2. Kereyev A.B., Sarsekenova A.K., Zhaltassov S.Zh. Soprovozhdenie geologo-gidrodinamicheskoy modeli mestorozhdeniya Uaz Severny po sostoyaniyu na 01.09.2023. [Support of the geological and hydrodynamic model of the Uaz Severny field as of 01.09.2023]. Atyrau: Atyrau branch of LLP “KMG Engineering”, 2024.3.3. Detalizatsiya geologicheskogo stroeniya mestorozhdeniy Uaz i Kondybai po dannym 3D seysmorazvedki. [Detailed geological structure of the Uaz and Kondybai fields based on 3D seismic data]. LLP “Reservoir Evaluation Services”, 2017.4.4. Utochnenie geologicheskogo stroeniya mestorozhdeniy Uaz i Kondybai po dannym bureniya. [Refinement of the geological structure of the Uaz and Kondybai fields based on drilling data]. LLP “Reservoir Evaluation Services”, 2019.5.5. Selley R.C. Vvedenie v sedimentologiyu. [An introduction to sedimentology]. Moscow: Nedra, 1981.6.6. G.E.-A. Eisenstadt, S.N. Koltypin, S.S. Razmyslova. Neftegasonosnye tolshchi Prikaspiiskoi vpadiny. – Leningrad: Nedra, 1967.7.7. Pettijohn F.J. Sedimentary Rocks. Third edition. Moscow: Nedra, 1981.8.8. Russian-Kazakh-English oil and gas dictionary – Astana: JSC EP KazMunayGas, 2006.