Abstract
The relevance of this study is due to the need for a detailed study of recoverable oil reserves in reservoirs of productive horizons, which is associated with the conditions of sedimentation and deposit formation processes within the South Turgai sedimentary basin. A comprehensive analysis, including granulometric studies of terrigenous sediments, is required to accurately determine the conditions of rock formation. This approach allows to obtain reliable data on the depositional environment and to perform a more detailed facies analysis. The aim of the study is to determine the facies of sedimentation of the South Kumkol productive horizon Y-II using granulometric analysis. The methodology of the study includes application of various methods of granulometric analysis. The generalised Fuchtbauer and Muller definition of depositional setting was used as the main approach. Genetic interpretation of sediments is based on the K. Björlikke diagram analysing the ratio of sorting and asymmetry of particle distribution. The G.F. Rozhkov dynamogenetic diagram, which takes into account the ratio of asymmetry and excess, was used to clarify sedimentation conditions. The results of the study make it possible to characterise more objectively the conditions of reservoir rock formation and specify sedimentation parameters. An integrated approach to the analysis of granulometric data helps to improve the accuracy of facies diagnostics of oil-bearing horizons.