CONSTRUCTION OF A GEOLOGICAL RESERVOIR MODEL BASED ON A COMPREHENSIVE ANALYSIS OF GEOLOGICAL AND GEOPHYSICAL DATA

The article presents the results of a comprehensive analysis of geological and geophysical data from a field located in the southern part of the Pre-Caspian sedimentary basin, characterized by complex fault-block structures, active halogenesis processes, and high lithological–stratigraphic variability. The study utilized drilling data, including core analysis, spectral gamma-ray logging, neutron–acoustic surveys, results of petrophysical interpretation, as well as refined re-interpretation of 3D seismic data. Integration of diverse information enabled the construction of a detailed three-dimensional geological model of productive horizons (Lower Albian, Aptian, and Neocomian formations), incorporating structural, lithological, and petrophysical modeling. Five structural segments were identified, the fault system was refined, and the spatial distribution of facies and reservoir zones with commercial potential was determined. Reservoir properties vary: effective porosity ranges from 13–19%, water saturation from 24–36%. The use of indicator modeling and Gaussian simulation improved the accuracy of the geological concept reproduction and the model’s consistency with actual data. The results provide a more precise assessment of hydrocarbon accumulation geometry, reserves distribution, and reservoir parameters, thus reducing geological risks and uncertainties. The developed model serves as the basis for hydrodynamic modeling, designing efficient development systems, and optimizing field operations.