Differentiated approach to the study of reservoirs and its influence on the calculated parameters (on the example of deposits of Pashiysky horizon of the field of the Republic of Bashkortostan)

UDK: 26.314.135 + 553.98

DOI: 10.24887/0028-2448-2025-11-77-81

Key words: Devonian, oil, petrophysical class, clay content, fraction, deposit parameters, hydrocarbon reserves

Authors: A.M. Nigmatzyanova (RN-BashNIPIneft LLC, RF, Ufa); V.V. Sidorkina (Rosneft Oil Company, RF, Moscow); R.Kh. Masagutov (Academy of Sciences of the Republic of Bashkortostan, RF, Ufa; Ufa State Petroleum Technological University, RF, Ufa); T.V. Burikova (RN-BashNIPIneft LLC, RF, Ufa); O.R. Privalova,5 (RN-BashNIPIneft LLC, RF, Ufa; Ufa University of Science and Technology, RF, Ufa); V.I. Shavaliev (RN-BashNIPIneft LLC, RF, Ufa)

The Devonian terrigenous strata the Pashiysky horizon in particular of the Republic of Bashkortostan has long remained the main complex for oil production, which is of significant interest to Rosneft Oil Company. However, even with such a high level of study, there remain marginal sections of structures and exploration areas, are poorly covered by exploratory and exploration drilling, which may be of interest for research. This publication summarizes the results of applying the classification of reservoirs of terrigenous Devonian deposits. Differentiation of reservoirs by type based on a combination of core data and geophysical research methods enables more detailed analysis of research materials, which influences the choice of the optimal development system, which corresponds to modern approaches used by Rosneft Oil Company in the regions of its operations. It takes into account the structural features and filtration-capacity characteristics of both clean and clay reservoirs and enables to develop more advanced dependencies for determining the oil and gas saturation of productive formations. Comparison of the filtration-capacity properties of the «T» field with the results of petrophysical typification of terrigenous Devonian deposits showed that the use of the obtained dependencies when recalculating reserves can lead to their increase and an increase in the accuracy of the forecast of the filtration properties of reservoirs. For Rosneft Oil Company, this is of particular importance in the development of mature fields. The proposed methodological approaches can be used for fields with similar geological conditions, both in Bashkortostan and in other regions.

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